header advert
Results 701 - 800 of over 10000
Results per page:
Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 8 - 8
1 Dec 2022
Pelletier-Roy R Dionne A Richard-Denis A Briand M Bourassa-Moreau E Mac-Thiong J
Full Access

Acute spinal cord injury (SCI) is most often secondary to trauma, and frequently presents with associated injuries. A neurological examination is routinely performed during trauma assessment, including through Advanced Trauma Life Support (ATLS). However, there is no standard neurological assessment tool specifically used for trauma patients to detect and characterize SCI during the initial evaluation. The International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) is the most comprehensive and popular tool for assessing SCI, but it is not adapted to the acute trauma patients such that it is not routinely used in that setting. Therefore, the objective is to develop a new tool that can be used routinely in the initial evaluation of trauma patients to detect and characterize acute SCI, while preserving basic principles of the ISNCSCI.

The completion rate of the ISCNSCI during the initial evaluation after an acute traumatic SCI was first estimated. Using a modified Delphi technique, we designed the Montreal Acute Classification of Spinal Cord Injuries (MAC-SCI), a new tool to detect and characterize the completeness (grade) and level of SCI in the polytrauma patient. The ability of the MAC-SCI to detect and characterize SCI was validated in a cohort of 35 individuals who have sustained an acute traumatic SCI. The completeness and neurological level of injury (NLI) were assessed by two independent assessors using the MAC-SCI, and compared to those obtained with the ISNCSCI.

Only 33% of patients admitted after an acute traumatic SCI had a complete ISNCSCI performed at initial presentation. The MAC-SCI includes 53 of the 134 original elements of the ISNCSCI which is 60% less. There was a 100% concordance between the severity grade derived from the MAC-SCI and from the ISNCSCI. Concordance of the NLI within two levels of that obtained from the ISNCSCI was observed in 100% of patients with the MAC-SCI and within one level in 91% of patients. The ability of the MAC-SCI to discriminate between cervical (C0 to C7) vs. thoracic (T1 to T9) vs. thoraco-lumbar (T10 to L2) vs. lumbosacral (L3 to S5) injuries was 100% with respect to the ISNCSCI.

The rate of completion of the ISNCSCI is low at initial presentation after an acute traumatic SCI. The MAC-SCI is a streamlined tool proposed to detect and characterize acute SCI in polytrauma patients, that is specifically adapted to the acute trauma setting. It is accurate for determining the completeness of the SCI and localize the NLI (cervical vs. thoracic vs. lumbar). It could be implemented in the initial trauma assessment protocol to guide the acute management of SCI patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 18 - 18
1 Dec 2022
Taha M Hadden W Ibrahim M Abdelbary H
Full Access

Prosthetic joint infection (PJI) is a complex disease that causes significant damage to the peri-implant tissue. Developing an animal model that is clinically relevant in depicting this disease process is an important step towards developing novel successful therapies. In this study, we have performed a thorough histologic analysis of peri-implant tissue harvested post Staphylococcus aureus (S. aureus) infection of a cemented 3D-printed titanium hip implant in rats.

Sprague-Dawley rats underwent left hip cemented 3D-printed titanium hemiarthroplasty via posterior approach under general anesthesia. Four surgeries were performed for the control group and another four for the infected group. The hip joint was inoculated with 5×109 CFU/mL of S. aureus Xen36 prior to capsule closure. The animals were scarified 3 weeks after infection. The femur was harvested and underwent micro-CT and histologic analysis. Hematoxylin and eosin (H&E), as well as Masson's trichrome (MT) stains were performed. Immunohistochemistry (IHC) using rabbit antibody for S. aureus was also used to localize bacterial presence within femur and acetabulum tissue .

The histologic analysis revealed strong resemblance to tissue changes in the clinical setting of chronic PJI. IHC demonstrated the extent of bacterial spread within the peri-implant tissue away from the site of infection. The H&E and MT stains showed 5 main features in infected bone: 1) increased PMNs, 2) fibrovascular inflammation, 3) bone necrosis, and 4) increased osteoclasts 5) fibrosis of muscular tissue and cartilage. Micro CT data showed significantly more osteolysis present around the infected prosthesis compared to control (surgery with no infection).

This is the first clinically relevant PJI animal model with detailed histologic analysis that strongly resembles the clinical tissue pathology of chronic PJI. This model can provide a better understanding of how various PJI therapies can halt or reverse peri-implant tissue damage caused by infection.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 19 - 19
1 Dec 2022
Eltit F Wang Q Xu S Satra M Liu D Wang R Charest-Morin R Cox M
Full Access

One out of nine Canadian males would suffer prostate cancer (PC) during his lifetime. Life expectancy of males with PC has increased with modern therapy and 90% live >10 years. However, 20% of PC-affected males would develop incurable metastatic diseases. Bone metastases (BM) are present in ~80% of metastatic PC patients, and are the most severe complication of PC, generating severe pain, fractures, spinal cord compression, and death. Interestingly, PC-BMs are mostly osteoblastic. However, the structure of this newly formed bone and how it relates to pain and fracture are unknown. Due to androgen antagonist treatment, different PC phenotypes develop with differential dependency on androgen receptor (AR) signaling: androgen-dependent (AR+), double negative (AR-) and neuroendocrine. How these phenotypes are related to changes in bone structure has not been studied. Here we show a state-of-the-art structural characterization of PCBM and how PC phenotypes are associated to abnormal bone formation in PCBM.

Cadaveric samples (n=14) obtained from metastases of PC in thoracic or lumbar vertebrae (mean age 74yo) were used to analyze bone structure. We used micro-computed tomography (mCT) to analyze the three-dimensional structure of the bone samples. After imaging, the samples were sectioned and one 3mm thick section was embedded in epoxy-resin, ground and polished. Scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) and quantitative backscattering electron (qBSE) imaging were used to determine mineral morphology and composition. Another section was used for histological analysis of the PC-affected bone. Collagen structure, fibril orientation and extracellular matrix composition were characterized using histochemistry. Additionally, we obtained biopsies of 3 PCBM patients undergoing emergency decompression surgery following vertebral fracture and used them for immunohistological characterization.

By using mCT, we observed three dysmorphic bone patterns: osteolytic pattern with thinned trabecula of otherwise well-organized structures, osteoblastic pattern defined as accumulation of disorganized matrix deposited on pre-existing trabecula, and osteoblastic pattern with minimum residual trabecula and bone space dominated by accumulation of disorganized mineralized matrix. Comparing mCT data with patho/clinical parameters revealed a trend for higher bone density in males with larger PSA increase. Through histological sections, we observed that PC-affected bone, lacks collagen alignment structure, have a higher number of lacunae and increased amount of proteoglycans as decorin.

Immunohistochemistry of biopsies revealed that PC-cells inside bone organize into two manners: i) glandular-like structures where cells maintain their polarization in the expression of prostate markers, ii) diffuse infiltrate that spreads along bone surfaces, with loss of cell polarity. These cells take direct contact with osteoblasts in the surface of trabecula. We define that PCBM are mostly composed by AR+ with some double negative cells. We did not observe neuroendocrine phenotype cells.

PCBMs generate predominantly osteoblastic lesions that are characterized by high lacunar density, lack of collagen organization and elevated proteoglycan content. These structural changes are associated with the infiltration of PC cells that are mostly androgen-dependent but have lost their polarization and contact directly with osteoblasts, perhaps altering their function. These changes could be associated with lower mechanical properties that led to fracture and weakness of the PCBM affected bone.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 21 - 21
1 Dec 2022
Cherry A Montgomery S Brillantes J Osborne T Khoshbin A Daniels T Ward S Atrey A
Full Access

In 2020, the COVID-19 pandemic meant that proceeding with elective surgery was restricted to minimise exposure on the wards. In order to maintain throughput of elective cases, our hospital was forced to convert as many cases as possible to same day procedures rather than overnight admission. In this retrospective analysis we review the cases performed as same day arthroplasty surgeries compared to the same period 12 months previous.

We conducted a retrospective analysis of patients undergoing total hip and knee arthroplasties in a three month period between October and December in 2019 and again in 2020, in the middle of the SARS-CoV-2 pandemic. Patient demographics, number of out-patient primary arthroplasty cases, length of stay for admissions, 30-day readmission and complications were collated.

In total, 428 patient charts were reviewed for the months of October-December of 2019 (n=195) and 2020 (n=233). Of those, total hip arthroplasties comprised 60% and 58.8% for 2019 and 2020, respectively. Demographic data was comparable with no statistical difference for age, gender contralateral joint replacement or BMI. ASA grade I was more highly prevalent in the 2020 cohort (5.1x increase, n=13 vs n=1). Degenerative disc disease and fibromyalgia were less significantly prevalent in the 2020 cohort. There was a significant increase in same day discharges for non-DAA THAs (2x increase) and TKA (10x increase), with a reciprocal decrease in next day discharges. There were significantly fewer reported superficial wound infections in 2020 (5.6% vs 1.7%) and no significant differences in readmissions or emergency department visits (3.1% vs 3.0%).

The SARS-CoV-2 pandemic meant that hospitals and patients were hopeful to minimise the exposure to the wards and to not put strain on the already taxed in-patient beds. With few positives during the Coronavirus crisis, the pandemic was the catalyst to speed up the outpatient arthroplasty program that has resulted in our institution being more efficient and with no increase in readmissions or early complications.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 35 - 35
1 Dec 2022
Verhaegen J Innmann MM Batista NA Merle C Grammatopoulos G
Full Access

Adverse spinopelvic characteristics (ASC) have been associated with increased dislocation risk following primary total hip arthroplasty (THA). A stiff lumbar spine, a large posterior standing tilt when standing and severe sagittal spinal deformity have been identified as key risk factors for instability. It has been reported that the rate of dislocation in patients with such ASC may be increased and some authors have recommended the use of dual mobility bearings or robotics to reduce instability to within acceptable rates (<2%).

The aims of the prospective study were to 1: Describe the true incidence of ASC in patients presenting for a THA 2. Assess whether such characteristics are associated with greater symptoms pre-THA due to the concomitant dual pathology of hip and spine and 3. Describe the early term dislocation rate with the use of ≤36mm bearings.

This is an IRB-approved, two-center, multi-surgeon, prospective, consecutive, cohort study of 220 patients undergoing THA through anterolateral- (n=103; 46.8%), direct anterior- (n=104; 27.3%) or posterior- approaches (n=13; 5.9%). The mean age was 63.8±12.0 years (range: 27.7-89.0 years) and the mean BMI 28.0±5.0 kg/m2 (range: 19.4-44.4 kg/m2). There were 44 males (47.8%) and 48 females (52.2%). The mean follow-up was 1.6±0.5 years. Overall, 54% of femoral heads was 32 mm, and 46% was 36mm.

All participants underwent lateral spinopelvic radiographs in the standing and deep-flexed seated positions were taken to determine lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic-femoral angle (PFA) and pelvic incidence (PI) in both positions. Spinal stiffness was defined as lumbar flexion <20° when transitioning between the standing and deep-seated position; adverse standing PT was defined as >19° and adverse sagittal lumbar balance was defined as mismatch between standing PI and LL >10°.

Pre-operative patient reported outcomes was measured using the Oxford Hip Score (OHS) and EuroQol Five-Dimension questionnaire (EQ-5D). Dislocation rates were prospectively recorded. Non-parametric tests were used, significance was set at p<0.05.

The prevalence of PI-LL mismatch was 22.1% (43/195) and 30.4% had increased standing PT (59/194). The prevalence of lumbar stiffness was 3.5% (5/142) and these patients had all three adverse spinopelvic characteristics (5/142; 3.5%).

There was no significant difference in the pre-operative OHS between patients with (20.7±7.6) and patients without adverse spinopelvic characteristics (21.6±8.7; p=0.721), nor was there for pre-operative EQ5D (0.651±0.081 vs. 0.563±0.190; p=0.295).

Two patients sustained a dislocation (0.9%): One in the lateral (no ASC) and one in the posterior approaches, who also exhibited ASC pre-operatively.

Sagittal lumbar imbalance, increased standing spinal tilt and spinal stiffness are not uncommon among patients undergoing THA. The presence of such characteristics is not associated with inferior pre-operative PROMs. However, when all characteristics are present, the risk of instability is increased. Patients with ASC treated with posterior approach THA may benefit from the use of advanced technology due to a high risk of dislocation. The use of such technology with the anterior or lateral approach to improve instability is to date unjustified as the rate of instability is low even amongst patients with ASCs.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 18 - 18
1 Dec 2022
Singh S Miyanji F
Full Access

The routine use of intraoperative vancomycin powder to prevent postoperative wound infections has not been borne out in the literature in the pediatric spine population. The goal of this study is to determine the impact of vancomycin powder on postoperative wound infection rates and determine its potential impact on microbiology.

A retrospective analysis of the Harms Study Group database of 1269 adolescent idiopathic scoliosis patients was performed. Patients that underwent a posterior fusion from 2004-2018 were analyzed. A comparative analysis of postoperative infection rates was done between patients that received vancomycin powder to those who did not. Statistical significance was determined using Chi-squared test. Additionally, the microbiology of infected patients was examined.

In total, 765 patients in the vancomycin group (VG) were compared to 504 patients in the non-vancomycin group (NVG). NVG had a significantly higher rate of deep wound infection (p<0.0001) and associated reoperation rate compared to VG (p<0.0001). Both groups were compared for age, gender, race, weight, surgical time, blood loss, number of levels instrumented, and preop curve magnitude. There were significant differences between the groups for race (p<0.0001); surgical time (p=0.0033), and blood loss (p=0.0021). In terms of microbiology, VG grew p.acnes (n=2), and serratia (n=1), whereas NVG grew p.acnes (n=1) and gram positive bacilli (n=1). The remaining cultures were negative.

The use of intraoperative vancomycin powder in adolescent idiopathic scoliosis appears to contribute significantly to deep wound infection prevention and reduction of associated reoperations. Based on this study's limited culture data, Vancomycin does not seem to alter the microbiology of deep wound infections.


Acute Compartment Syndrome (ACS) is an orthopaedic emergency that can develop after a wide array of etiologies. In this pilot study the MY01 device was used to assess its ease of use and its ability to continuously reflect the intracompartmental pressure (ICP) and transmit this data to a mobile device in real time. This preliminary data is from the lead site which is presently expanding data collection to five other sites as part of a multi-center study.

Patients with long bone trauma of the lower or upper extremity posing a possibility of developing compartment syndrome were enrolled in the study. Informed consent was obtained from the patients. A Health Canada licensed continuous compartmental pressure monitor (MY01) was used to measure ICP. The device was inserted in the compartment that was deemed most likely to develop ACS and ICP was continuously measured for up to 18 hours. Fractures were classified according to the AO/OTA classification. Patient clinical signs and pain levels were recorded by healthcare staff during routine in-patient monitoring and were compared to the ICP from the device. Important treatment information was pulled from the patient's chart to help correlate all of the patient's data and symptoms.

The study period was conducted from November 2020 through December 2021. Twenty-six patients were enrolled. There were 17 males, and nine females. The mean age was 38 years (range, 17–76). Seventeen patients received the device post-operatively and nine received it pre-operatively. Preliminary results show that post-operative ICPs tend to be significantly higher than pre-operative ICPs but tend to trend downwards very quickly. The trend in this measurement appears to be more significant than absolute numbers which is a real change from the previous literature. One patient pre-operatively illustrated a steep trend upwards with minimal clinical symptoms but required compartment release at the time of surgery that exhibited no muscle necrosis. The trend in this patient was very steep and, as predicted, predated the clinical findings of compartment syndrome. This trend allows an early warning signal of the absolute pressure, to come, in the compartment that is being assessed by the device.

Preliminary results suggest that this device is reliable and relatively easy to use within our institutions. In addition it suggests that intracompartmental pressures can be higher immediately post-op but lower rapidly when the patient does not develop ACS. These results are in line with current literature of the difference between pre and post-operative baselines and thresholds of ICP, but are much more striking, as continuous measurements have not been part of the data set in most of past studies.

Further elucidation of the pressure thresholds and profiles are currently being studied in the ongoing larger multicenter study and will add to our understanding of the critical values. This data, plus the added value of continuous trends in the pressure, upwards or downwards, will aid in preventing muscle necrosis during our management of these difficult long bone fractures.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 20 - 20
1 Dec 2022
O'Connor K Zwicker J Chhina H Cooper A
Full Access

A huge commitment is required from patients and families who undergo a limb reconstruction procedure using the hexapod frame. This includes turning the struts on the frame, pin site care and intensive rehabilitation. Montpetit et al (2009) discovered that function, participation, engagement in regular activities of daily living is severely impacted during the hexapod lengthening period. Due to the long duration and burden for families, it is imperative that healthcare professionals understand the impact that the hexapod frame has on functional abilities and health related quality of life (HRQL).

This project involved a retrospective review of prospectively collected data on function and HRQL during two periods of time: (1) when the hexapod frame is applied on the child's lower extremity and (2) when the lengthening phase is completed, and the hexapod frame is removed. Data from 38 children (mean age: 12 years SD 3.8) who completed lower extremity reconstruction using the hexapod frame and completed either or both the Pediatric Quality of Life Inventory 4.0 Generic Core Scale (PedsQL) and Pediatric Outcomes data Collection Instrument (PODCI) was included. Analysis included, standardized response means, the non-parametric Wilcoxon test and effect size calculation.

A Wilcoxon signed rank test for those children who completed pre and post frame PODCI’;s revealed those scores were significantly greater once the hexapod frame was removed (Md=85.10, n=10) compared to during (Md=66.50, n=10) with a large effect size, r= 1.45. Similar, the PedsQL scores improved post frame removal (Md= 66.30, n=10) compared to during treatment (Md = 53.34, n=10), with a medium size effect, r= 0.62. All subtests improved once the frame was removed.

This study provides essential insights into the burden of the hexapod frame for children and provides valuable information for all allied healthcare professionals targeted interventions for health domains. This study shows that children's function improves once the hexapod frame is removed. However, this study highlights the importance for all healthcare professional to address health domains for the duration of the hexapod procedure where the child scored lower e.g. sports and physical function, pain and comfort, happiness from the PODCI. The PedsQL identified lower mean scores in physical and emotional function.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 21 - 21
1 Dec 2022
Kim D Dermott J Lebel D Howard AW
Full Access

Primary care physicians rely on radiology reports to confirm a scoliosis diagnosis and inform the need for spine specialist referral. In turn, spine specialists use these reports for triage decisions and planning of care. To be a valid predictor of disease and management, radiographic evaluation should include frontal and lateral views of the spine and a complete view of the pelvis, leading to accurate Cobb angle measurements and Risser staging. The study objectives were to determine 1) the adequacy of index images to inform treatment decisions at initial consultation by generating a score and 2) the utility of index radiology reports for appropriate triage decisions, by comparing reports to corresponding images.

We conducted a retrospective chart and radiographic review including all idiopathic scoliosis patients seen for initial consultation, aged three to 18 years, between January 1-April 30, 2021. A score was generated based on the adequacy of index images to provide accurate Cobb angle measurements and determine skeletal maturity (view of full spine, coronal=two, lateral=one, pelvis=one, ribcage=one). Index images were considered inadequate if repeat imaging was necessary. Comparisons were made between index radiology report, associated imaging, and new imaging if obtained at initial consultation. Major discrepancies were defined by inter-reader difference >15°, discordant Risser staging, or inaccuracies that led to inappropriate triage decisions. Location of index imaging, hospital versus community-based private clinic, was evaluated as a risk factor for inadequate or discrepant imaging.

There were 94 patients reviewed with 79% (n=74) requiring repeat imaging at initial consultation, of which 74% (n=55) were due to insufficient quality and/or visualization of the sagittal profile, pelvis or ribcage. Of index images available for review at initial consult (n=80), 41.2% scored five out of five and 32.5% scored two or below. New imaging showed that 50.0% of those patients had not been triaged appropriately, compared to 18.2% of patients with a full score. Comparing index radiology reports to initial visit evaluation with <60 days between imaging (n=49), discrepancies in Cobb angle were found in 24.5% (95% CI 14.6, 38.1) of patients, with 18.4% (95% CI 10.0, 31.4) categorized as major discrepancies. Risser stage was reported in only 14% of index radiology reports. In 13.8% (n=13) of the total cohort, surgical or brace treatment was recommended when not predicted based on index radiology report. Repeat radiograph (p=0.001, OR=8.38) and discrepancies (p=0.02, OR=7.96) were increased when index imaging was obtained at community-based private clinic compared to at a hospital. Re-evaluation of available index imaging demonstrated that 24.6% (95% CI 15.2, 37.1) of Cobb angles were mis-reported by six to 21 degrees.

Most pre-referral paediatric spine radiographs are inadequate for idiopathic scoliosis evaluation. Standardization of spine imaging and reporting should improve measurement accuracy, facilitate triage and decrease unnecessary radiation exposure.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 40 - 40
1 Dec 2022
Schmidt-Braekling T Thavorn K Poitras S Gofton W Kim P Beaulé P Grammatopoulos G
Full Access

With an ageing population and an increasing number of primary arthroplasties performed, the revision burden is predicted to increase. The aims of this study were to 1. Determine the revision burden in an academic hospital over a 11-year period; 2. identify the direct hospital cost associated with the delivery of revision service and 3. ascertain factors associated with increased cost.

This is an IRB-approved, retrospective, single tertiary referral center, consecutive case series. Using the hospital data warehouse, all patients that underwent revision hip or knee arthroplasty surgery between 2008-2018 were identified. 1632 revisions were identified (1304 patients), consisting of 1061 hip and 571 knee revisions. The majority of revisions were performed for mechanical-related problems and aseptic loosening (n=903; 55.3%); followed by periprosthetic joint infection (n=553; 33.9%) and periprosthetic fractures (176; 10.8%). Cost and length of stay was determined for all patient. The direct in-hospital costs were converted to 2020 inflation-adjusted Canadian dollars. Several patients- (age; gender; HOMR- and ASA-scores; Hemoglobin level) and surgical- (indication for surgery; surgical site) factors were tested for possible associations.

The number of revisions increased by 210% in the study period (2008 vs. 2018: 83 vs. 174). Revision indications changed over study period; with prevalence of fracture increasing by 460% (5 in 2008 vs. 23 in 2018) with an accompanying reduction in mechanical-related reasons, whilst revisions for infection remained constant. The mean annual cost over the entire study period was 3.9 MMCAD (range:2.4–5.1 MMCAD). The cost raised 150% over the study period from 2.4 MMCAD in 2008 to 3.6 MMCAD. Revisions for fractured had the greatest length of stay, the highest mean age, HOMR-score, ASA and cost associated with treatment compared to other revision indications (p < 0 .001). Patient factors associated with cost and length of stay included ASA- and HOMR-scores, Charlson-Comorbidity score and age.

The revision burden increased 1.5-fold over the years and so has the direct cost of care delivery. The increased cost is primarily related to the prolonged hospital stay and increased surgical cost. For tertiary care units, these findings indicate a need to identify strategies on improving efficiencies whilst improving the quality of patient care (e.g. efficient ways of reducing acute hospital stay) and reducing the raise of the economic burden on a publicly funded health system.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 42 - 42
1 Dec 2022
Fransen B Howard L MacDonell T Bengoa F Garbuz D Sheridan G Neufeld M
Full Access

Increased femoral head size reduces the rate of dislocation after total hip arthroplasty (THA). With the introduction of highly crosslinked polyethylene (HXLPE) liners in THA there has been a trend towards using larger size femoral heads in relatively smaller cup sizes, theoretically increasing the risk of liner fracture, wear, or aseptic loosening. Short to medium follow-up studies have not demonstrated a negative effect of using thinner HXLPE liners. However, there is concern that these thinner liners may prematurely fail in the long-term, especially in those with thinner liners. The aim of this study was to evaluate the long-term survival and revision rates of HXLPE liners in primary THA, as well as the effect of liner thickness on these outcomes. We hypothesized that there would be no significant differences between the different liner thicknesses.

We performed a retrospective database analysis from a single center of all primary total hip replacements using HXLPE liners from 2010 and earlier, including all femoral head sizes. All procedures were performed by fellowship trained arthroplasty surgeons. Patient characteristics, implant details including liner thickness, death, and revisions (all causes) were recorded. Patients were grouped for analysis for each millimeter of PE thickness (e.g. 4.0-4.9mm, 5.0-5.9mm). Kaplan-Meier survival estimates were estimated with all-cause and aseptic revisions as the endpoints.

A total of 2354 patients (2584 hips) were included (mean age 64.3 years, min-max 19-96). Mean BMI was 29.0 and 47.6% was female. Mean follow-up was 13.2 years (range 11.0-18.8). Liner thickness varied from 4.9 to 12.7 mm. Seven patients had a liner thickness <5.0mm and 859 had a liner thickness of <6.0mm. Head sizes were 28mm (n=85, 3.3%), 32mm (n=1214, 47.0%), 36mm (n=1176, 45.5%), and 40mm (n=109, 4.2%), and 98.4% were metal heads. There were 101 revisions, and in 78 of these cases the liner was revised. Reason for revision was instability/dislocation (n=34), pseudotumor/aseptic lymphocyte-dominant vasculitis associated lesion (n=18), fracture (n=17), early loosening (n=11), infection (n=7), aseptic loosening (n=4), and other (n=10). When grouped by liner thickness, there were no significant differences between the groups when looking at all-cause revision (p=0.112) or aseptic revision (p=0.116).

In our cohort, there were no significant differences in all-cause or aseptic revisions between any of the liner thickness groups at long-term follow-up. Our results indicate that using thinner HXPE liners to maximize femoral head size in THA does not lead to increased complications or liner failures at medium to long term follow-up. As such, orthopedic surgeons can consider the use of larger heads at the cost of liner thickness a safe practice to reduce the risk of dislocation after THA when using HXLPE liners.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 25 - 25
1 Dec 2022
Asma A Ulusaloglu A Shrader MW Mackenzie W Scavina M Heinle R Howard J
Full Access

Prior to the introduction of steroid management in Duchenne Muscular Dystrophy (DMD), the prevalence of scoliosis approached 100%, concomitant with progressive decreases in pulmonary function. As such, early scoliosis correction (at 20-25°) was advocated, prior to substantial pulmonary function decline. With improved pulmonary function and delayed curve progression with steroid treatment, the role of early surgery has been questioned. The purpose of this study was to compare the post-operative outcomes of early versus late scoliosis correction in DMD. We hypothesize that performing later surgery with larger curves would not lead to worse post-operative complications.

Retrospective cohort study. Patients with DMD who underwent posterior scoliosis correction, had pre-operative pulmonary function testing, and at least 1-year post-operative follow-up, were included; divided into 2 Groups by pre-operative curve angle – 1: ≤45°, 2: >45°. Primary outcome was post-operative complications by Clavien-Dindo (CD) grading. Secondary outcomes included: age at surgery, forced vital capacity (FVC), steroid utilization, fractional shortening (FS) by echocardiogram, surgery duration, blood transfusion requirements, ICU length of stay (LOS), days intubated post-operatively, hospital LOS, infection, curve correction. Two-tailed t-test and chi-square testing were used for analysis of patient factors and CD complication grade, respectively.

31 patients met the inclusion criteria, with a mean total follow-up of 8.3±3.2 years. Steroid treatment (prednisone, deflazacort) was utilized for 21 (67.7%) patients, for a mean duration of 8.2±4.0 years. Groups were comparable for steroid use, FVC, echo FS, and age at surgery (p>0.05). Primary curve angle was 31.7±10.4° and 58.3±11.1° for Groups 1 and 2, respectively (p 0.05). Surgery duration, ICU LOS, days intubated, hospital LOS, were also not different between Groups. For the entire cohort, however, the overall complication rate was higher for patients with steroid treatment [61.9% vs 10%, respectively (p=0.008)], the majority being CDII. Neither FVC nor echo FS were different between Groups at final follow-up (p=0.6; p=0.4, respectively).

Post-operative complication rates were not different for early and late scoliosis correction in DMD. In general, however, patients undergoing steroid treatment were at higher risk of blood transfusion and deep infection. Delaying scoliosis correction in DMD while PF is favourable is reasonable, but patients with prior steroid treatment should be counseled regarding the higher risk of complications.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 17 - 17
1 Dec 2022
Smit K L'Espérance C Livock H Tice A Carsen S Jarvis J Kerrigan A Seth S
Full Access

Olecranon fractures are common injuries representing roughly 5% of pediatric elbow fractures. The traditional surgical management is open reduction and internal fixation with a tension band technique where the pins are buried under the skin and tamped into the triceps. We have used a modification of this technique, where the pins have been left out of the skin to be removed in clinic. The purpose of the current study is to compare the outcomes of surgically treated olecranon fractures using a tension-band technique with buried k-wires (PINS IN) versus percutaneous k-wires (PINS OUT).

We performed a retrospective chart review on all pediatric patients (18 years of age or less) with olecranon fractures that were surgically treated at a pediatric academic center between 2015 to present. Fractures were identified using ICD-10 codes and manually identified for those with an isolated olecranon fracture. Patients were excluded if they had polytrauma, metabolic bone disease, were treated non-op or if a non-tension band technique was used (ex: plate/screws). Patients were then divided into 2 groups, olecranon fractures using a tension-band technique with buried k-wires (PINS IN) and with percutaneous k-wires (PINS OUT). In the PINS OUT group, the k-wires were removed in clinic at the surgeon's discretion once adequate fracture healing was identified. The 2 groups were then compared for demographics, time to mobilization, fracture healing, complications and return to OR.

A total of 35 patients met inclusion criteria. There were 28 patients in the PINS IN group with an average age of 12.8 years, of which 82% male and 43% fractured their right olecranon. There were 7 patients in the PINS OUT group with an average age of 12.6 years, of which 57% were male and 43% fractured their right olecranon. All patients in both groups were treated with open reduction internal fixation with a tension band-technique. In the PINS IN group, 64% were treated with 2.0 k-wires and various materials for the tension band (82% suture, 18% cerclage wire). In the PINS OUT group, 71% were treated with 2.0 k-wires and all were treated with sutures for the tension band. The PINS IN group were faster to mobilize (3.4 weeks (range 2-5 weeks) vs 5 weeks (range 4-7 weeks) p=0.01) but had a significantly higher complications rate compared to the PINS OUT group (6 vs 0, p =0.0001) and a significantly higher return to OR (71% vs 0%, p=0.0001), mainly for hardware irritation or limited range of motion. All fractures healed in both groups within 7 weeks.

Pediatric olecranon fractures treated with a suture tension-band technique and k-wires left percutaneously is a safe and alternative technique compared to the traditional buried k-wires technique. The PINS OUT technique, although needing longer immobilization, could lead to less complications and decreased return to the OR due to irritation and limited ROM.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 48 - 48
1 Dec 2022
Yee N Iorio C Shkumat N Rocos B Ertl-Wagner B Green A Lebel D Camp M
Full Access

Neuromuscular scoliosis patients face rates of major complications of up to 49%. Along with pre-operative risk reduction strategies (including nutritional and bone health optimization), intra-operative strategies to decrease blood loss and decrease surgical time may help mitigate these risks. A major contributor to blood loss and surgical time is the insertion of instrumentation which is challenging in neuromuscular patient given their abnormal vertebral and pelvic anatomy. Standard pre-operative radiographs provide minimal information regarding pedicle diameter, length, blocks to pedicle entry (e.g. iliac crest overhang), or iliac crest orientation. To minimize blood loss and surgical time, we developed an “ultra-low dose” CT protocol without sedation for neuromuscular patients.

Our prospective quality improvement study aimed to determine: if ultra-low dose CT without sedation was feasible given the movement disorders in this population; what the radiation exposure was compared to standard pre-operative imaging; whether the images allowed accurate assessment of the anatomy and intra-operative navigation given the ultra-low dose and potential movement during the scan.

Fifteen non-ambulatory surgical patients with neuromuscular scoliosis received the standard spine XR and an ultra-low dose CT scan. Charts were reviewed for etiology of neuromuscular scoliosis and medical co-morbidities. The CT protocol was a high-speed, high-pitch, tube-current modulated acquisition at a fixed tube voltage. Adaptive statistical iterative reconstruction was applied to soft-tissue and bone kernels to mitigate noise. Radiation dose was quantified using reported dose indices (computed tomography dose index (CTDIvol) and dose-length product (DLP)) and effective dose (E), calculated through Monte-Carlo simulation. Statistical analysis was completed using a paired student's T-test (α = 0.05). CT image quality was assessed for its use in preoperative planning and intraoperative navigation using 7D Surgical System Spine Module (7D Surgical, Toronto, Canada).

Eight males and seven females were included in the study. Their average age (14±2 years old), preoperative Cobb angle (95±21 degrees), and kyphosis (60±18 degrees) were recorded. One patient was unable to undergo the ultra-low dose CT protocol without sedation due to a co-diagnosis of severe autism. The average XR radiation dose was 0.5±0.3 mSv. Variability in radiographic dose was due to a wide range in patient size, positioning (supine, sitting), number of views, imaging technique and body habitus. Associated CT radiation metrics were CTDIvol = 0.46±0.14 mGy, DLP = 26.2±8.1 mGy.cm and E = 0.6±0.2 mSv. CT radiation variability was due to body habitus and arm orientation. The radiation dose differences between radiographic and CT imaging were not statistically significant. All CT scans had adequate quality for preoperative assessment of pedicle diameter and orientation, obstacles impeding pedicle entry, S2-Alar screw orientation, and intra-operative navigation.

“Ultra-low dose” CT scans without sedation were feasible in paediatric patients with neuromuscular scoliosis. The effective dose was similar between the standard preoperative spinal XR and “ultra-low dose” CT scans. The “ultra-low dose” CT scan allowed accurate assessment of the anatomy, aided in pre-operative planning, and allowed intra-operative navigation despite the movement disorders in this patient population.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 66 - 66
1 Dec 2022
Lamer S Ma Z Mazy D Chung-Tze-Cheong C Nguyen A Li J Nault M
Full Access

Meniscal tears are the most common knee injuries, occurring in acute ruptures or in chronic degenerative conditions. Meniscectomy and meniscal repair are two surgical treatment options. Meniscectomy is easier, faster, and the patient can return to their normal activities earlier. However, this procedure has long-term consequences in the development of degenerative changes in the knee, potentially leading to knee replacement. On the other hand, meniscal repair can offer prolonged benefits to the patients, but it is difficult to perform and requires longer rehabilitation.

Sutures are used for meniscal repairs, but they have limitations. They induce tissue damage when passing through the meniscus. Furthermore, under dynamic loading of the knee, they can cause tissue shearing and potentially lead to meniscal repair failure.

Our team has developed a new technology of resistant adhesive hydrogels to coat the suture used to repair meniscal tissue.

The objective of this study is to biomechanically compare two suture types on bovine menisci specimens: 1) pristine sutures and 2) gel adhesive puncture sealing (GAPS) sutures, on a repaired radial tear under cyclic tensile testing.

Five bovine knees were dissected to retrieve the menisci. On the 10 menisci, a complete radial tear was performed. They were separated in two groups and repaired using either pristine (2-0 Vicryl) or GAPS (2-0 Vicryl coated with adhesive hydrogels) with a single stitch and five knots.

The repaired menisci were clamped on an Instron machine. The specimens were cyclically preconditioned between one and 10 newtons for 10 cycles and then cyclically loaded for 500 cycles between five and 25 newtons at a frequency of 0.16 Hz. The gap formed between the edges of the tear after 500 cycles was then measured using an electronic measurement device. The suture loop before and after testing was also measured to ensure that there was no suture elongation or loosening of the knot.

The groups were compared statistically using Mann-Whitney tests for nonparametric data. The level of significance was set to 0.05.

The mean gap formation of the pristine sutures was 5.61 mm (SD = 2.097) after 500 cycles of tensile testing and 2.38 mm (SD = 0.176) for the GAPS sutures. Comparing both groups, the gap formed with the coated sutures was significantly smaller (p = 0.009) than with pristine sutures. The length of the loop was equal before and after loading. Further investigation of tissue damage indicated that the gap was formed by suture filament cutting into the meniscal tissue.

The long-term objective of this research is to design a meniscal repair toolbox from which the surgeon can adapt his procedure for each meniscal tear. This preliminary experimentation on bovine menisci is promising because the new GAPS sutures seem to keep the edges of the meniscal tear together better than pristine sutures, with hopes of a clinical correlation with enhanced meniscal healing.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 67 - 67
1 Dec 2022
You D Korley R Duffy P Martin R Dodd A Buckley R Soo A Schneider P
Full Access

Prolonged bedrest in hospitalized patients is a major risk factor for venous thromboembolism (VTE), especially in high risk patients with hip fracture. Thrombelastography (TEG) is a whole blood viscoelastic hemostatic assay with evidence that an elevated maximal amplitude (MA), a measure of clot strength, is predictive of VTE in orthopaedic trauma patients. The objective of this study was to compare the TEG MA parameter between patients with hip fracture who were more mobile post-operatively and discharged from hospital early to patients with hip fracture with reduced mobility and prolonged hospitalizations post-operatively.

In this prospective cohort study, TEG analysis was performed in patients with hip fracture every 24-hours from admission until post-operative day (POD) 5, then at 2- and 6-weeks post-operatively. Hypercoagulability was defined by MA > 65. Patients were divided into an early (within 5-day) and late (after 5-day) discharge group, inpatient at 2-weeks group, and discharge to MSK rehabilitation (MSK rehab), and long term care (LTC) groups. Two-sample t-test was used to analyze differences in MA between the early discharge and less mobile groups. All statistical tests were two-sided, and p-values < 0.05 were considered statistically significant.

In total, 121 patients with a median age of 81.0 were included. Patients in the early discharge group (n=15) were younger (median age 64.0) and more likely to ambulate without gait aids pre-injury (86.7%) compared to patients in the late discharge group (n=105), inpatients at 2-weeks (n=48), discharged to MSK rehab (n=30), and LTC (n=20). At two weeks post-operative, the early discharge group was significantly less hypercoagulable (MA=68.9, SD 3.0) compared to patients in the other four groups. At 6-weeks post-operative, the early discharge group was the only group to demonstrate a trend towards mean MA below the MA > 65 hypercoagulable threshold (MA=64.4, p=0.45). Symptomatic VTE events were detected in three patients (2.5%) post-operatively. All three patients had hospitalizations longer than five days after surgery.

In conclusion, our analysis of hypercoagulability secondary to reduced post-operative mobility demonstrates that patients with hip fracture who were able to mobilize independently sooner after hip fracture surgery, have a reduced peak hypercoagulable state. In addition, there is a trend towards earlier return to normal coagulation status as determined by the TEG MA parameter. Post-operative mobility status may play a role in determining individualized duration of thromboprophylaxis following hip fracture surgery. Future studies comparing TEG to clinically validated mobility tools may more closely evaluate the contribution of venous stasis due to reduced mobility on hypercoagulation following hip fracture surgery.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 68 - 68
1 Dec 2022
Yee N Lorio C Shkumat N Rocos B Ertl-Wagner B Green A Lebel D Camp M
Full Access

Neuromuscular scoliosis patients face rates of major complications of up to 49%. Along with pre-operative risk reduction strategies (including nutritional and bone health optimization), intra-operative strategies to decrease blood loss and decrease surgical time may help mitigate these risks. A major contributor to blood loss and surgical time is the insertion of instrumentation which is challenging in neuromuscular patient given their abnormal vertebral and pelvic anatomy. Standard pre-operative radiographs provide minimal information regarding pedicle diameter, length, blocks to pedicle entry (e.g. iliac crest overhang), or iliac crest orientation. To minimize blood loss and surgical time, we developed an “ultra-low dose” CT protocol without sedation for neuromuscular patients.

Our prospective quality improvement study aimed to determine:

if ultra-low dose CT without sedation was feasible given the movement disorders in this population;

what the radiation exposure was compared to standard pre-operative imaging;

whether the images allowed accurate assessment of the anatomy and intra-operative navigation given the ultra-low dose and potential movement during the scan.

Fifteen non-ambulatory surgical patients with neuromuscular scoliosis received the standard spine XR and an ultra-low dose CT scan. Charts were reviewed for etiology of neuromuscular scoliosis and medical co-morbidities. The CT protocol was a high-speed, high-pitch, tube-current modulated acquisition at a fixed tube voltage. Adaptive statistical iterative reconstruction was applied to soft-tissue and bone kernels to mitigate noise. Radiation dose was quantified using reported dose indices (computed tomography dose index (CTDIvol) and dose-length product (DLP)) and effective dose (E), calculated through Monte-Carlo simulation. Statistical analysis was completed using a paired student's T-test (α= 0.05). CT image quality was assessed for its use in preoperative planning and intraoperative navigation using 7D Surgical System Spine Module (7D Surgical, Toronto, Canada).

Eight males and seven females were included in the study. Their average age (14±2 years old), preoperative Cobb angle (95±21 degrees), and kyphosis (60±18 degrees) were recorded. One patient was unable to undergo the ultra-low dose CT protocol without sedation due to a co-diagnosis of severe autism. The average XR radiation dose was 0.5±0.3 mSv. Variability in radiographic dose was due to a wide range in patient size, positioning (supine, sitting), number of views, imaging technique and body habitus. Associated CT radiation metrics were CTDIvol = 0.46±0.14 mGy, DLP = 26.2±8.1 mGy.cm and E = 0.6±0.2 mSv. CT radiation variability was due to body habitus and arm orientation. The radiation dose differences between radiographic and CT imaging were not statistically significant. All CT scans had adequate quality for preoperative assessment of pedicle diameter and orientation, obstacles impeding pedicle entry, S2-Alar screw orientation, and intra-operative navigation.

“Ultra-low dose” CT scans without sedation were feasible in paediatric patients with neuromuscular scoliosis. The effective dose was similar between the standard preoperative spinal XR and “ultra-low dose” CT scans. The “ultra-low dose” CT scan allowed accurate assessment of the anatomy, aided in pre-operative planning, and allowed intra-operative navigation despite the movement disorders in this patient population.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 69 - 69
1 Dec 2022
Clarke M Beaudry E Besada N Oguaju B Nathanail S Westover L Sommerfeldt M
Full Access

Meniscal root tears can result from traumatic injury to the knee or gradual degeneration. When the root is injured, the meniscus becomes de-functioned, resulting in abnormal distribution of hoop stresses, extrusion of the meniscus, and altered knee kinematics. If left untreated, this can cause articular cartilage damage and rapid progression of osteoarthritis. Multiple repair strategies have been described; however, no best fixation practice has been established. To our knowledge, no study has compared suture button, interference screw, and HEALICOIL KNOTLESS fixation techniques for meniscal root repairs. The goal of this study is to understand the biomechanical properties of these fixation techniques and distinguish any advantages of certain techniques over others. Knowledge of fixation robustness will aid in surgical decision making, potentially reducing failure rates, and improving clinical outcomes.

19 fresh porcine tibias with intact medial menisci were randomly assigned to four groups: 1) native posterior medial meniscus root (PMMR) (n = 7), 2) suture button (n = 4), 3) interference screw (n = 4), or 4) HEALICOIL KNOTLESS (n = 4). In 12 specimens, the PMMR was severed and then refixed by the specified group technique. The remaining seven specimens were left intact. All specimens underwent cyclic loading followed by load-to-failure testing. Elongation rate; displacement after 100, 500, and 1000 cycles; stiffness; and maximum load were recorded.

Repaired specimens had greater elongation rates and displacements after 100, 500, and 1000 cycles than native PMMR specimens (p 0.05). The native PMMR showed greater maximum load than all repair techniques (p 0.05). In interference screw and HEALICOIL KNOTLESS specimens, failure occurred as the suture was displaced from the fixation and tension was gradually lost. In suture button specimens, the suture was either displaced or completely separated from the button. In some cases, tear formation and partial failure also occurred at the meniscus luggage tag knot. Native PMMR specimens failed through meniscus or meniscus root tearing.

All fixation techniques showed similar biomechanical properties and performed inferiorly to the native PMMR. Evidence against significant differences between fixation techniques suggests that the HEALICOIL KNOTLESS technique may present an additional option for fixation in meniscal root repairs. While preliminary in vitro evidence suggests similarities between fixation techniques, further research is required to determine if clinical outcomes differ.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 70 - 70
1 Dec 2022
Hébert S Charest-Morin R Bédard L Pelet S
Full Access

Despite the current trend favoring surgical treatment of displaced intra-articular calcaneal fractures (DIACFs), studies have not been able to demonstrate superior functional outcomes when compared to non-operative treatment. These fractures are notoriously difficult to reduce. Studies investigating surgical fixation often lack information about the quality of reduction even though it may play an important role in the success of this procedure. We wanted to establish if, amongst surgically treated DIACF, an anatomic reduction led to improved functional outcomes at 12 months.

From July 2011 to December 2020, at a level I trauma center, 84 patients with an isolated DIACF scheduled for surgical fixation with plate and screws using a lateral extensile approach were enrolled in this prospective cohort study and followed over a 12-month period. Post-operative computed tomography (CT) imaging of bilateral feet was obtained to assess surgical reduction using a combination of pre-determined parameters: Böhler's angle, calcaneal height, congruence and articular step-off of the posterior facet and calcaneocuboid (CC) joint. Reduction was judged anatomic when Böhler's angle and calcaneal height were within 20% of the contralateral foot while the posterior facet and CC joint had to be congruent with a step-off less than 2 mm. Several functional scores related to foot and ankle pathology were used to evaluate functional outcomes (American Orthopedic Foot and Ankle Score - AOFAS, Lower Extremity Functional Score - LEFS, Olerud and Molander Ankle Score - OMAS, Calcaneal Functional Scoring System - CFSS, Visual Analog Scale for pain – VAS) and were compared between anatomic and nonanatomic DIAFCs using Student's t-test. Demographic data and information about injury severity were collected for each patient.

Among the 84 enrolled patients, 6 were excluded while 11 were lost to follow-up. Thirty-nine patients had a nonanatomic reduction while 35 patients had an anatomic reduction (47%). Baseline characteristics were similar in both groups. When we compared the injury severity as defined by the Sanders’ Classification, we did not find a significant difference. In other words, the nonanatomic group did not have a greater proportion of complex fractures. Anatomically reduced DIACFs showed significantly superior results at 12 months for all but one scoring system (mean difference at 12 months: AOFAS 3.97, p = 0.12; LEFS 7.46, p = 0.003; OMAS 13.6, p = 0.002, CFSS 7.5, p = 0.037; VAS −1.53, p = 0.005). Univariate analyses did not show that smoking status, worker's compensation or body mass index were associated with functional outcomes. Moreover, fracture severity could not predict functional outcomes at 12 months.

This study showed superior functional outcomes in patients with a DIACF when an anatomic reduction is achieved regardless of the injury severity.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 72 - 72
1 Dec 2022
Kendal J Fruson L Litowski M Sridharan S James M Purnell J Wong M Ludwig T Lukenchuk J Benavides B You D Flanagan T Abbott A Hewison C Davison E Heard B Morrison L Moore J Woods L Rizos J Collings L Rondeau K Schneider P
Full Access

Distal radius fractures (DRFs) are common injuries that represent 17% of all adult upper extremity fractures. Some fractures deemed appropriate for nonsurgical management following closed reduction and casting exhibit delayed secondary displacement (greater than two weeks from injury) and require late surgical intervention. This can lead to delayed rehabilitation and functional outcomes. This study aimed to determine which demographic and radiographic features can be used to predict delayed fracture displacement.

This is a multicentre retrospective case-control study using radiographs extracted from our Analytics Data Integration, Measurement and Reporting (DIMR) database, using diagnostic and therapeutic codes. Skeletally mature patients aged 18 years of age or older with an isolated DRF treated with surgical intervention between two and four weeks from initial injury, with two or more follow-up visits prior to surgical intervention, were included. Exclusion criteria were patients with multiple injuries, surgical treatment with fewer than two clinical assessments prior to surgical treatment, or surgical treatment within two weeks of injury. The proportion of patients with delayed fracture displacement requiring surgical treatment will be reported as a percentage of all identified DRFs within the study period. A multivariable conditional logistic regression analysis was used to assess case-control comparisons, in order to determine the parameters that are mostly likely to predict delayed fracture displacement leading to surgical management. Intra- and inter-rater reliability for each radiographic parameter will also be calculated.

A total of 84 age- and sex-matched pairs were identified (n=168) over a 5-year period, with 87% being female and a mean age of 48.9 (SD=14.5) years. Variables assessed in the model included pre-reduction and post-reduction radial height, radial inclination, radial tilt, volar cortical displacement, injury classification, intra-articular step or gap, ulnar variance, radiocarpal alignment, and cast index, as well as the difference between pre- and post-reduction parameters. Decreased pre-reduction radial inclination (Odds Ratio [OR] = 0.54; Confidence Interval [CI] = 0.43 – 0.64) and increased pre-reduction volar cortical displacement (OR = 1.31; CI = 1.10 – 1.60) were significant predictors of delayed fracture displacement beyond a minimum of 2-week follow-up. Similarly, an increased difference between pre-reduction and immediate post reduction radial height (OR = 1.67; CI = 1.31 – 2.18) and ulnar variance (OR = 1.48; CI = 1.24 – 1.81) were also significant predictors of delayed fracture displacement.

Cast immobilization is not without risks and delayed surgical treatment can result in a prolong recovery. Therefore, if reliable and reproducible radiographic parameters can be identified that predict delayed fracture displacement, this information will aid in earlier identification of patients with DRFs at risk of late displacement. This could lead to earlier, appropriate surgical management, rehabilitation, and return to work and function.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 11 - 11
1 Dec 2022
Tolgyesi A Huang C Akens M Hardisty M Whyne C
Full Access

Bone turnover and the accumulation of microdamage are impacted by the presence of skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact bone quality. The present study aims to establish a preliminary understanding of microdamage accumulation and load to failure in osteolytic vertebrae following stereotactic body radiotherapy (SBRT), zoledronic acid (ZA), or docetaxel (DTX) treatment.

Twenty-two six-week old athymic female rats (Hsd:RH-Foxn1rnu, Envigo, USA) were inoculated with HeLa cervical cancer cells through intracardiac injection (day 0). Institutional approval was obtained for this work and the ARRIVE guidelines were followed. Animals were randomly assigned to four groups: untreated (n=6), spine stereotactic body radiotherapy (SBRT) administered on day 14 (n=6), zoledronic acid (ZA) administered on day 7 (n=5), and docetaxel (DTX) administered on day 14 (n=5). Animals were euthanized on day 21. T13-L3 vertebral segments were collected immediately after sacrifice and stored in −20°C wrapped in saline soaked gauze until testing. µCT scans (µCT100, Scanco, Switzerland) of the T13-L3 segment confirmed tumour burden in all T13 and L2 vertebrae prior to testing. T13 was stained with BaSO4 to label microdamage. High resolution µCT scans were obtained (90kVp, 44uA, 4W, 4.9µm voxel size) to visualize stain location and volume. Segmentations of bone and BaSO4 were created using intensity thresholding at 3000HU (~736mgHA/cm3) and 10000HU (~2420mgHA/cm3), respectively. Non-specific BaSO4 was removed from the outer edge of the cortical shell by shrinking the segmentation by 105mm in 3D. Stain volume fraction was calculated as the ratio of BaSO4 volume to the sum of BaSO4 and bone volume. The L1-L3 motion segments were loaded under axial compression to failure using a µCT compatible loading device (Scanco) and force-displacement data was recorded. µCT scans were acquired unloaded, at 1500µm displacement and post-failure. Stereological analysis was performed on the L2 vertebrae in the unloaded µCT scans. Differences in mean stain volume fraction, mean load to failure, and mean bone volume/total volume (BV/TV) were compared between treatment groups using one-way ANOVAs. Pearson's correlation between stain volume fraction and load to failure by treatment was calculated using an adjusted load to failure divided by BV/TV.

Stained damage fraction was significantly different between treatment groups (p=0.0029). Tukey post-hoc analysis showed untreated samples to have higher stain volume fraction (16.25±2.54%) than all treatment groups (p<0.05). The ZA group had the highest mean load to failure (195.60±84.49N), followed by untreated (142.33±53.08N), DTX (126.60±48.75N), and SBRT (95.50±44.96N), but differences did not reach significance (p=0.075). BV/TV was significantly higher in the ZA group (49.28±3.56%) compared to all others. The SBRT group had significantly lower BV/TV than the untreated group (p=0.018). Load divided by BV/TV was not significantly different between groups (p=0.24), but relative load to failure results were consistent (ZA>Untreated>DTX>SBRT). No correlations were found between stain volume fraction and load to failure.

Focal and systemic cancer treatments effect microdamage accumulation and load to failure in osteolytic vertebrae. Current testing of healthy controls will help to further separate the effects of the tumour and cancer treatments on bone quality.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 92 - 92
1 Dec 2022
Thibault J Grammatopoulos G Horton I Harris N Dodd-Moher M Papp S
Full Access

In patients admitted to hospital with a hip fracture, urinary issues are common. Despite guidelines that recommend avoiding foley catheter usage when possible, it remains a common part of perioperative care. To date, there is no prospective data on the safety and satisfaction associated with catheter use in such cohort. The aim of this study was to evaluate the satisfaction of patients when using a foley catheter while they await surgery for their fractured hip and the safety associated with catheter use.

In our prospectively collected database, 587 patients were admitted to our tertiary care center over a 1 year period. Most patients (328) were catheterized within the first 24h of admission, primarily inserted in ED. Of these patients, 119 patients (61 catheterized and 58 noncatheterized) completed a questionnaire about their perioperative management with foley catheter usage administered on day 1 of admission. This was used to determine satisfaction of catheter use (if catheterized) and pain levels (associated with catheterized or associated with transferring/voiding if not catheterized). Adverse effects related with catheter use included urinary tract infection (UTI) and post-operative urinary retention (POUR).

Ninety-five percent of patients found the catheter to be convenient. Only 5% of patients reported any pain with catheter use. On the contrary, 47.5% of non-catheterized patients found it difficult to move to the bathroom and 30.4% found it difficult to urinate. Catheterized patients had significative less pain than uncatheterized patients (0.62/10 vs 2.45/10 respectively, p < 0 .001). The use of nerve block reduced pain levels amongst catheterized patients but was not associated with reduced pain levels or satisfaction amongst non-catheterized patients. The use of catheter was not associated with increased risk of UTI(17.5% in the catheterized vs 13.3% in the non-catheterized, p = 0.541) or POUR (6.8% in the catheterized vs 11.1% in the non-catheterized, p = 0.406).

This study illustrates the benefits and safety associated with the use of urinary catheters in the pre-operative period amongst hip fractures. The use of catheters was associated with reduced pain and satisfaction without increasing post-operative UTI or POUR. These findings suggest that pre-operative catheter use is associated with less pain and more satisfaction for patients awaiting hip surgery and whom other measures, such as nerve blocks, are unlikely to reduce the discomfort associated with the mobility required to void. A prospective randomized control study could lead to a more evidence based approach for perioperative foley catheter usage in hip fracture patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 94 - 94
1 Dec 2022
Versteeg A Chisamore N Ng K Elmoursi O Leroux T Zywiel M
Full Access

While surgeon-industry relationships in orthopaedics have a critical role in advancing techniques and patient outcomes, they also present the potential for conflict of interest (COI) and increased risk of bias in surgical education. Consequently, robust processes of disclosure and mitigation of potential COI have been adopted across educational institutions, professional societies, and specialty journals. The past years have seen marked growth in the use of online video-based surgical education platforms that are commonly used by both trainees and practicing surgeons. However, it is unclear to what extent the same COI disclosure and mitigation principles are adhered to on these platforms. Thus, the purpose of the present study was to evaluate the frequency and adequacy of potential COI disclosure on orthopaedic online video-based educational platforms.

We retrospectively reviewed videos from a single, publicly-accessible online peer-to-peer orthopaedic educational video platform (VuMedi) that is used as an educational resource by a large number of orthopaedic trainees across North America. The 25 highest-viewed videos were identified for each of 6 subspecialty areas (hip reconstruction, knee reconstruction, shoulder/elbow, foot and ankle, spine and sports). A standardized case report form was developed based on the COI disclosure guidelines of the American Academy of Orthopaedic Surgery (AAOS) and the Journal of Bone and Joint Surgery. Two reviewers watched and assessed each video for presentation of any identifiable commercial products or brand names, disclosure of funding source for video, and presenter's potential conflict of interest. Additionally, presenter disclosures were cross-referenced against commercial relationships reported in the AAOS disclosure database to determine adequacy of disclosure. Any discrepancies between reviewers were resolved by consensus wherever possible, or with adjudication by a third reviewer when necessary.

Out of 150 reviewed videos, only 37 (25%) included a disclosure statement of any kind. Sixty-nine (46%) videos involved the presentation of a readily identifiable commercial orthopaedic device, implant or brand. Despite this, only 13 of these (19%) included a disclosure of any kind, and only 8 were considered adequate when compared to the presenter's disclosures in the AAOS database. In contrast, 83% of the presenters of the videos included in this study reported one or more commercial relationships in the AAOS disclosure database.

Videos of presentations given at conferences and/or academic meetings had significantly greater rates of disclosure as compared to those that were not (41% vs 14%; p=0.004). Similarly, disclosures associated with conference/meeting presentations had significantly greater rates of adequacy (21% vs 7%; p=0.018). Even so, less than half of the educational videos originating from a conference or meeting included a disclosure of any kind, and only about half of these were deemed adequate. No differences were seen in the rate of disclosures between orthopaedic subspecialties (p=0.791).

Online orthopaedic educational videos commonly involve presentation of specific, identifiable commercial products and brands, and the large majority of presenters have existing financial relationships with potential for conflict of interest. Despite this, the overall rate of disclosure of potential conflict of interest in these educational videos is low, and many of these disclosures are incomplete or inadequate. Further work is needed to better understand the impact of this low rate of disclosure on orthopaedic education both in-training and in practice.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 95 - 95
1 Dec 2022
Gleicher Y Wolfstadt J Entezari B
Full Access

Ankle fractures are common orthopedic injuries, often requiring operative intervention to restore joint stability, improve alignment, and reduce the risk of post-traumatic ankle arthritis. However, ankle fracture surgeries (AFSs) are associated with significant postoperative pain, typically requiring postoperative opioid analgesics. In addition to putting patients at risk of opioid dependence, the adverse effects of opioids include nausea, vomiting, and altered mental status which may delay recovery. Peripheral nerve blocks (PNBs) offer notable benefits to the postoperative pain profile when compared to general or spinal anaesthesia alone and may help improve recovery. The primary objective of this quality improvement (QI) study was to increase PNB administration for AFS at our institution to above 50% by January 2021.

A root cause analysis was performed by a multidisciplinary team to identify barriers for PNB administration. Four interventions were chosen & implemented: recruitment and training of expert anesthesiologists in regional anesthesia techniques, procurement of additional ultrasound machines, implementation of a dedicated block room with training to create an enhanced learning environment, and the development of an educational pamphlet for patients outlining strategies to manage rebound pain, instructions around the use of oral multimodal analgesia, and the potential for transient motor block of the leg.

The primary outcome was the percentage of patients who received PNB for AFS. Secondary outcome measures included total hospitalization length of stay (LOS), post-anesthesia care unit (PACU) and 24-hour postoperative opioid consumption (mean oral morphine equivalent [OME]), proportion of patients requiring opioid analgesic in PACU, and proportion of patients experiencing post-operative nausea and/or vomiting (PONV) requiring antiemetic in PACU. Thirty-day post-operative emergency department (ED) visits were collected as a balance measure.

The groups receiving PNB and not receiving PNB included 78 & 157 patients, respectively, with no significant differences in age, gender, or ASA class between groups. PNB administration increased from less than 10% to 53% following implementation of the improvement bundle. Mean total hospital LOS did not vary significantly across the PNB and no PNB groups (1.04 days vs. 1.42 days, P = 0.410). Both mean PACU and mean 24-hour postoperative opioid analgesic consumption was significantly lower in the PNB group compared to the no PNB group (OME in PACU 38.96mg vs. 55.42mg [P = 0.001]; 24-hour OME 44.74mg vs. 37.71mg [P = .008]). A greater proportion of patients in the PNB group did not require any PACU opioid analgesics compared to those in the no PNB group (62.8% vs. 27.4%, P < 0.001). The proportion of patients experiencing PONV and requiring antiemetic both in the PACU did not vary significantly across groups. Thirty-day postoperative ED visits did not vary significantly across groups.

By performing a root cause analysis and implementing a multidisciplinary, patient-centered QI bundle, we achieved significant increases in PNB administration for AFS. As a result, there were significant improvements in the recovery of patients following AFS, specifically reduced use of postoperative opioid analgesia. This multi-faceted approach provides a framework for an individualized QI approach to increase PNB administration and achieve improved patient outcomes following AFS.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 83 - 83
1 Dec 2022
Van Meirhaeghe J Vicente M Leighton R Backstein D Nousiainen M Sanders DW Dehghan N Cullinan C Stone T Schemitsch C Nauth A
Full Access

The management of periprosthetic distal femur fractures is an issue of increasing importance for orthopaedic surgeons. Because of the expanding indications for total knee arthroplasty (TKA) and an aging population with increasingly active lifestyles there has been a corresponding increase in the prevalence of these injuries. The management of these fractures is often complex because of issues with obtaining fixation around implants and dealing with osteopenic bone or compromised bone stock. In addition, these injuries frequently occur in frail, elderly patients, and the early restoration of function and ambulation is critical in these patients. There remains substantial controversy with respect to the optimal treatment of periprosthetic distal femur fractures, with some advocating for Locked Plating (LP), others Retrograde Intramedullary Nailing (RIMN) and finally those who advocate for Distal Femoral Replacement (DFR). The literature comparing these treatments, has been infrequent, and commonly restricted to single-center studies. The purpose of this study was to retrospectively evaluate a large series of operatively treated periprosthetic distal femur fractures from multiple centers and compare treatment strategies.

Patients who were treated operatively for a periprosthetic distal femur fracture at 8 centers across North America between 2003 and 2018 were retrospectively identified. Baseline characteristics, surgical details and post-operative clinical outcomes were collected from patients meeting inclusion criteria. Inclusion criteria were patients aged 18 and older, any displaced operatively treated periprosthetic femur fracture and documented 1 year follow-up. Patients with other major lower extremity trauma or ipsilateral total hip replacement were excluded. Patients were divided into 3 groups depending on the type of fixation received: Locked Plating, Retrograde Intramedullary Nailing and Distal Femoral Replacement. Documented clinical follow-up was reviewed at 2 weeks, 3 months, 6 months and 1 year following surgery. Outcome and covariate measures were assessed using basic descriptive statistics. Categorical variables, including the rate of re-operation, were compared across the three treatment groups using Fisher Exact Test.

In total, 121 patients (male: 21% / female: 79%) from 8 centers were included in our analysis. Sixty-seven patients were treated with Locked Plating, 15 with Retrograde Intramedullary Nailing, and 39 were treated with Distal Femoral Replacement. At 1 year, 64% of LP patients showed radiographic union compared to 77% in the RIMN group (p=0.747). Between the 3 groups, we did not find any significant differences in ambulation, return to work and complication rates at 6 months and 1 year (Table 1). Reoperation rates at 1 year were 27% in the LP group (17 reoperations), 16% in the DFR group (6 reoperations) and 0% in the RIMN group. These differences were not statistically significant (p=0.058).

We evaluated a large multicenter series of operatively treated periprosthetic distal femur fractures in this study. We did not find any statistically significant differences at 1 year between treatment groups in this study. There was a trend towards a lower rate of reoperation in the Retrograde Intramedullary Nailing group that should be evaluated further with prospective studies.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 15 - 15
1 Dec 2022
Tolgyesi A Huang C Akens M Hardisty M Whyne C
Full Access

Bone turnover and the accumulation of microdamage are impacted by the presence of skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact bone quality. The present study aims to establish a preliminary understanding of microdamage accumulation and load to failure in osteolytic vertebrae following stereotactic body radiotherapy (SBRT), zoledronic acid (ZA), or docetaxel (DTX) treatment.

Twenty-two six-week old athymic female rats (Hsd:RH-Foxn1rnu, Envigo, USA) were inoculated with HeLa cervical cancer cells through intracardiac injection (day 0). Institutional approval was obtained for this work and the ARRIVE guidelines were followed. Animals were randomly assigned to four groups: untreated (n=6), spine stereotactic body radiotherapy (SBRT) administered on day 14 (n=6), zoledronic acid (ZA) administered on day 7 (n=5), and docetaxel (DTX) administered on day 14 (n=5). Animals were euthanized on day 21. T13-L3 vertebral segments were collected immediately after sacrifice and stored in −20°C wrapped in saline soaked gauze until testing. µCT scans (µCT100, Scanco, Switzerland) of the T13-L3 segment confirmed tumour burden in all T13 and L2 vertebrae prior to testing. T13 was stained with BaSO4 to label microdamage. High resolution µCT scans were obtained (90kVp, 44uA, 4W, 4.9µm voxel size) to visualize stain location and volume. Segmentations of bone and BaSO4 were created using intensity thresholding at 3000HU (~736mgHA/cm3) and 10000HU (~2420mgHA/cm3), respectively. Non-specific BaSO4 was removed from the outer edge of the cortical shell by shrinking the segmentation by 105mm in 3D. Stain volume fraction was calculated as the ratio of BaSO4 volume to the sum of BaSO4 and bone volume. The L1-L3 motion segments were loaded under axial compression to failure using a µCT compatible loading device (Scanco) and force-displacement data was recorded. µCT scans were acquired unloaded, at 1500µm displacement and post-failure. Stereological analysis was performed on the L2 vertebrae in the unloaded µCT scans. Differences in mean stain volume fraction, mean load to failure, and mean bone volume/total volume (BV/TV) were compared between treatment groups using one-way ANOVAs. Pearson's correlation between stain volume fraction and load to failure by treatment was calculated using an adjusted load to failure divided by BV/TV.

Stained damage fraction was significantly different between treatment groups (p=0.0029). Tukey post-hoc analysis showed untreated samples to have higher stain volume fraction (16.25±2.54%) than all treatment groups (p<0.05). The ZA group had the highest mean load to failure (195.60±84.49N), followed by untreated (142.33±53.08N), DTX (126.60±48.75N), and SBRT (95.50±44.96N), but differences did not reach significance (p=0.075). BV/TV was significantly higher in the ZA group (49.28±3.56%) compared to all others. The SBRT group had significantly lower BV/TV than the untreated group (p=0.018). Load divided by BV/TV was not significantly different between groups (p=0.24), but relative load to failure results were consistent (ZA>Untreated>DTX>SBRT). No correlations were found between stain volume fraction and load to failure.

Focal and systemic cancer treatments effect microdamage accumulation and load to failure in osteolytic vertebrae. Current testing of healthy controls will help to further separate the effects of the tumour and cancer treatments on bone quality.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 24 - 24
1 Dec 2022
Searle S Reesor M Sadat M Bouchard M
Full Access

The Ponseti method is the gold standard treatment for clubfoot. It begins in early infancy with weekly serial casting for up to 3 months. Globally, a commonly reported barrier to accessing clubfoot treatment is increased distance patients must travel for intervention. This study aims to evaluate the impact of the distance traveled by families to the hospital on the treatment course and outcomes for idiopathic clubfoot. No prior studies in Canada have examined this potential barrier.

This is a retrospective cohort study of patients managed at a single urban tertiary care center for idiopathic clubfoot deformity. All patients were enrolled in the Pediatric Clubfoot Research Registry between 2003 and April 2021. Inclusion criteria consisted of patients presenting at after percutaneous Achilles tenotomy. Postal codes were used to determine distance from patients’ home address to the hospital. Patients were divided into three groups based on distance traveled to hospital: those living within the city, within the Greater Metro Area (GMA) and outside of the GMA (non-GMA). The primary outcome evaluated was occurrence of deformity relapse and secondary outcomes included need for surgery, treatment interruptions/missed appointments, and complications with bracing or casting.

A total of 320 patients met inclusion criteria. Of these, 32.8% lived in the city, 41% in the GMA and 26% outside of the GMA. The average travel distance to the treatment centre in each group was 13.3km, 49.5km and 264km, respectively. Over 22% of patients travelled over 100km, with the furthest patient travelling 831km.

The average age of presentation was 0.91 months for patients living in the city, 1.15 months for those within the GMA and 1.33 months for patients outside of the GMA. The mean number of total casts applied was similar with 7.1, 7.8 and 7.3 casts in the city, GMA and non-GMA groups, respectively.

At least one two or more-week gap was identified between serial casting appointments in 49% of patients outside the GMA, compared to 27% (GMA) and 24% (city). Relapse occurred in at least one foot in 40% of non-GMA patients, versus 27% (GMA) and 24% (city), with a mean age at first relapse of 50.3 months in non-GMA patients, 42.4 months in GMA and 35.7 months in city-dwelling patients. 12% of the non-GMA group, 6.8% of the GMA group and 5.7% of the city group underwent surgery, with a mean age at time of initial surgery of 79 months, 67 months and 76 months, respectively. Complications, such as pressure sores, casts slips and soiled casts, occurred in 35% (non-GMA), 32% (GMA) and 24% (city) of patients.

These findings suggest that greater travel distance for clubfoot management is associated with more missed appointments, increased risk of relapse and treatment complications. Distance to a treatment center is a modifiable barrier. Improving access to clubfoot care by establishing clinics in more remote communities may improve clinical outcomes and significantly decrease the burdens of travel on patients and families.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 44 - 44
1 Dec 2022
Turgeon T Bohm E Gascoyne T Hedden D Burnell C
Full Access

This study used model-based radiostereometric analysis (MBRSA) to compare migration of a recently introduced cementless hip stem to an established hip stem of similar design. Novel design features of the newer hip stem included a greater thickness of hydroxyapatite coating and a blended compaction extraction femoral broach.

Fifty-seven patients requiring primary total hip arthroplasty (THA) were enrolled at a single centre. Patients were randomized to receive either an Avenir collarless stem and Trilogy IT cup (ZimmerBiomet) or a Corail collarless stem and Pinnacle cup (DePuy Synthes) via a posterior or lateral approach. Both stems are broach-only femoral bone preparation. RSA beads (Halifax Biomedical) were inserted into the proximal femur during surgery. Patients underwent supine RSA imaging a 6 weeks (baseline), 6, 12, and 24 months following surgery. The primary study outcome was total subsidence of the hip stem from baseline to 24 months as well as progression of subsidence between 12 and 24 months. These values were compared against published migration thresholds for well-performing hip stems (0.5mm). The detection limit, or precision, of MBRSA was calculated based on duplicate examinations taken at baseline. Patient reported outcome measures were collected throughout the study and included the Oxford-12 Hip Score (OHS), EuroQoL EQ-5D-5L, Hip Osteoarthritis Score (HOOS) as well as visual analogue scales (VAS) for thigh pain and satisfaction. Analysis comprised of paired and unpaired t-tests with significance set at p≤0.05.

Forty-eight patients (30 males) were included for analysis; 7 patients received a non-study hip stem intra-operatively, 1 patient suffered a traumatic dislocation within three weeks of surgery, and 1 patient died within 12 months post-surgery. RSA data was obtained for 45 patients as three patients did not receive RSA beads intra-operatively. Our patient cohort had a mean age of 65.9 years (±;7.2) at the time of surgery and body mass index of 30.5 kg/m2 (±;5.2). No statistical difference in total stem migration was found between the Avenir and Corail stems at 12 months (p=0.045, 95%CI: −0.046 to 0.088) and 24 months (p=0.936, 95% CI: −0.098 to 0.090). Progression of subsidence from 12-24 months was 0.011mm and 0.034mm for the Avenir and Corail groups which were not statistically different (p=0.163, 95%CI: −0.100 to 0.008) between groups and significantly less than the 0.5mm threshold (pNo statistically significant differences existed between study groups for any pre-operative function scores (p>0.05). All patients showed significant functional improvement from pre- to post-surgery and no outcome measures were different between study groups with exception of EQ-5D-5L health visual analogue scale at 12 months which showed marginally superior (p=0.036) scores in the Avenir group. This study was not powered to detect differences in clinical outcomes.

This study has demonstrated no statistical difference in subsidence or patient-reported outcomes between the Corail hip stem and the more recently introduced Avenir hip stem. This result is predictable as both stems are of a triple-tapered design, are coated with hydroxyapatite, and utilize a broach-only bone preparation technique. Both stem designs demonstrate migration below 0.5mm suggesting both are low-risk for aseptic loosening in the long-term.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 46 - 46
1 Dec 2022
Sheridan G Garbuz D Masri B
Full Access

The demand for revision total knee arthroplasty (TKA) has grown significantly in recent years. The two major fixation methods for stems in revision TKA include cemented and ‘hybrid’ fixation. We explore the optimal fixation method using data from recent, well-designed comparative studies.

We performed a systematic review of comparative studies published within the last 10 years with a minimum follow-up of 24 months. To allow for missing data, a random-effects meta-analysis of all available cases was performed. The odds ratio (OR) for the relevant outcome was calculated with 95% confidence intervals. The effects of small studies were analyzed using a funnel plot, and asymmetry was assessed using Egger's test. The primary outcome measure was all-cause failure. Secondary outcome measures included all-cause revision, aseptic revision and radiographic failure.

There was a significantly lower failure rate for hybrid stems when compared to cemented stems (p = 0.006) (OR 0.61, 95% CI 0.42-0.87). Heterogeneity was 4.3% and insignificant (p = 0.39). There was a trend toward superior hybrid performance for all other outcome measures including all-cause re-revision, aseptic re-revision and radiographic failure.

Recent evidence suggests a significantly lower failure rate for hybrid stems in revision TKA. There is also a trend favoring the use of hybrid stems for all outcome variables assessed in this study. This is the first time a significant difference in outcome has been demonstrated through systematic review of these two modes of stem fixation. We therefore recommend the use, where possible, of hybrid stems in revision TKA.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 50 - 50
1 Dec 2022
Nagle M Lethbridge L Johnston E Richardson G Stringer M Boivin M Dunbar M
Full Access

Canada is second only to the United States worldwide in the number of opioid prescriptions per capita. Despite this, little is known about prescription patterns for patients undergoing total joint arthroplasty (TJA). The purpose of this study was to detail preoperative opioid use patterns and investigate the effect it has on perioperative quality outcomes in patients undergoing elective total hip and total knee arthroplasty surgery (THA and TKA).

The study cohort was constructed from hospital Discharge Abstract Data (DAD) and National Ambulatory Care Reporting System (NACRS) data, using Canadian Classification of Health Intervention codes to select all primary THA and TKA procedures from 2017-2020 in Nova Scotia. Opioid use was defined as any prescription filled at discharge as identified in the Nova Scotia Drug Information System (DIS). Emergency Department (ED) and Family Doctor (FD) visits for pain were ascertained from Physician Claims data. Multivariate logistic regression was used to test for associations controlling for confounders. Chi-squared statistics at 95% confidence level used to test for statistical significance.

In total, 14,819 TJA patients were analysed and 4306 patients (29.0%) had at least one opioid prescription in the year prior to surgery. Overall, there was no significant difference noted in preoperative opiate use between patients undergoing TKA vs THA (28.8% vs 29.4%). During the period 2017-2019 we observed a declining year-on-year trend in preoperative opiate use. Interestingly, this trend failed to continue into 2020, where preoperative opiate use was observed to increase by 15% and exceeded 2017 levels. Within the first 90 days of discharge, 22.9% of TKA and 20.9% of THA patients presented to the ED or their FD with pain related issues. Preoperative opiate use was found to be a statistically significant predictor for these presentations (TKA: odds ratio [OR], 1.45; 95% confidence interval [CI], 1.29 to 1.62; THA: OR, 1.46; 95% CI, 1.28 to 1.65).

Preoperative opioid consumption in TJA remains high, and is independently associated with a higher risk of 90 day return to the FD or ED. The widespread dissemination of opioid reduction strategies introduced during the middle of the last decade may have reduced preoperative opiate utilisation. Access barriers and practice changes due to the COVID-19 pandemic may now have annulled this effect.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 59 - 59
1 Dec 2022
Hoffer A Peck G Kingwell D McConkey M Leith J Lodhia P
Full Access

To document and assess the available evidence regarding single bundle, hamstrings autograft preparation techniques for Anterior Cruciate Ligament reconstruction (ACLR) and provide graft preparation options for different clinical scenarios.

Three online databases (Embase, PubMed and Ovid [MEDLINE]) were searched from database inception until April 10, 2021. The inclusion criteria were English language studies, human studies, and operative technique studies for single bundle hamstrings autograft preparation for ACLR. Descriptive characteristics, the number of tendons, number of strands, tendon length, graft length and graft diameter were recorded. The methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) instrument and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system for non-randomized and randomized studies, respectively.

The initial search yielded 5485 studies, 32 met the inclusion criteria. The mean MINORS score across all nonrandomized studies was 8.2 (standard deviation, SD 6.6) indicating an overall low quality of evidence. The mean MINORS score for comparative studies was 17.4 (SD 3.2) indicating a fair quality of evidence. The GRADE assessment for risk of bias in the randomized study included was low.

There were 2138 knees in 1881 participants, including 1296 (78.1%) males and 363 (21.9%) females recorded. The mean age was 30.3 years. The mean follow-up time was 43.9 months when reported (range 16-55 months). Eleven studies utilized the semitendinosus tendon alone, while 21 studies used both semitendinosus and gracilis tendons. There were 82 (3.8%) two-strand grafts, 158 (7.4%) three-strand grafts, 1044 (48.8%) four-strand grafts, 546 (25.5%) five-strand grafts, and 308 (14.4%) six-strand grafts included. Overall, 372 (19.7%) participants had a single-tendon ACLR compared to 1509 (80.2%) participants who had a two-tendon ACLR.

The mean graft diameter was 9.4mm when reported. The minimum semitendinosus and gracilis tendon lengths necessary ranged from 210-280mm and 160-280mm respectively. The minimum graft length necessary ranged from 63-120mm except for an all-epiphyseal graft in the paediatric population that required a minimum length of 50mm. The minimum femoral, tibial, and intra-articular graft length ranged from 15-25mm, 15-35mm and 20-30mm respectively. Thirteen studies detailed intra-operative strategies to increase graft size such as adding an extra strand or altering the tibial and/or femoral fixation strategies to shorten and widen the graft.

Two studies reported ACL reinjury or graft failure rate. One study found no difference in the re-injury rate between four-, five- and six-strand grafts (p = 0.06) and the other found no difference in the failure rate between four- and five- strand grafts (p = 0.55). There was no difference in the post-operative Lysholm score in 3 studies that compared four- and five-strand ACLR. One of the five studies that compared post-operative IKDC scores between graft types found a difference between two- and three- strand grafts, favoring three-strand grafts.

There are many single bundle hamstrings autograft preparation techniques for ACLR that have been used successfully with minimal differences in clinical outcomes. There are different configurations that may be utilized interchangeably depending on the number, size and length of tendons harvested to obtain an adequate graft diameter and successful ACLR.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 60 - 60
1 Dec 2022
Yin D Couture J
Full Access

Direct oral anticoagulant (DOAC) use is becoming more widespread in the geriatric population. Depending on the type of DOAC, several days are required for its anticoagulant effects to resorb, which may lead to surgical delays. This can have an important impact on hip fracture patients who require surgery. The goal of the current study is to compare surgical delays, mortality and complications for hip fracture patients who were on a DOAC to those who were not.

A retrospective cohort study was conducted at a university hospital in Sherbrooke. All hip fracture patients between 2012 and 2018 who were on a DOAC prior to their surgery were included. These patients were matched with similar patients who were not on an anticoagulant (non-DOAC) for age, sex, type of fracture and date of operation. Demographic and clinical data were collected for all patients. Surgical delay was defined as time of admission to time of surgery. Mortality and complications up to one year postoperative were also noted.

Each cohort comprised of 74 patients. There were no statistically signification differences in Charleson Comorbidty Index and American Society of Anesthesiologists scores between cohorts. Surgical delay was significantly longer for DOAC patients (36.3±22.2 hours vs. 18.6±18.9 hours, p < 0 .001). Mortality (6.1%) and overall complication (33.8%) rates were similar between the two cohorts. However, there were more surgical reinterventions in DOAC patients than non-DOAC ones (16.2% vs. 0.0%, p < 0 .001). Among DOAC patients, mortality was greater for those operated after 48 hours (23.1% vs. 3.3%, p < 0 .05) and complications were more frequent for those operated after 24 hours (52.0% vs. 37.5%, p < 0 .05).

Direct oral anticoagulant (DOAC) use in hip fracture patients is associated with longer surgical delays. Longer delays to surgery are associated with higher mortality and complication rates in hip fracture patients taking a DOAC. Hip fracture patients should have their surgery performed as soon as medically possible, regardless of anticoagulant use.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 44 - 44
1 Dec 2022
Dumas E Fleury C LaRue B Bedard S Goulet J Couture J Lebel K Bigney E Manson N Abraham EP El-Mughayyar D Cherry A Richardson E Attabib N Small C Vandewint A Kerr J McPhee R
Full Access

Pain management in spine surgery can be challenging. Cannabis might be an interesting choice for analgesia while avoiding some side effects of opioids. Recent work has reported on the potential benefits of cannabinoids for multimodal pain control, but very few studies focus on spinal surgery patients. This study aims to examine demographic and health status differences between patients who report the use of (1) cannabis, (2) narcotics, (3) cannabis and narcotics or (4) no cannabis/narcotic use.

Retrospective cohort study of thoracolumbar patients enrolled in the CSORN registry after legalization of cannabis in Canada. Variables included: age, sex, modified Oswestry Disability Index (mODI), Numerical Rating Scales (NRS) for leg and back pain, tingling/numbness leg sensation, SF-12 Quality of Life- Mental Health Component (MCS), Patient Health Questionnaire (PHQ-9), and general health state. An ANCOVA with pathology as the covariate and post-hoc analysis was run.

The majority of the 704 patients enrolled (mean age: 59; female: 46.9%) were non-users (41.8%). More patients reported narcotic-use than cannabis-use (29.7% vs 12.9%) with 13.4% stating concurrent-use. MCS scores were significantly lower for patients with concurrent-use compared to no-use (mean of 39.95 vs 47.98, p=0.001) or cannabis-use (mean=45.66, p=0.043). The narcotic-use cohort had significantly worse MCS scores (mean=41.37, p=0.001) than no-use. Patients reporting no-use and cannabis-use (mean 41.39 vs 42.94) had significantly lower ODI scores than narcotic-use (mean=54.91, p=0.001) and concurrent-use (mean=50.80, p=0.001). Lower NRS-Leg pain was reported in cannabis-use (mean=5.72) compared to narcotic-use (mean=7.19) and concurrent-use (mean=7.03, p=0.001). No-use (mean=6.31) had significantly lower NRS-Leg pain than narcotic-use (p=0.011), and significantly lower NRS-back pain (mean=6.17) than narcotic-use (mean=7.16, p=0.001) and concurrent-use (mean=7.15, p=0.012). Cannabis-use reported significantly lower tingling/numbness leg scores (mean=4.85) than no-use (mean=6.14, p=0.022), narcotic-use (mean=6.67, p=0.001) and concurrent-use (mean=6.50, p=0.01). PHQ-9 scores were significantly lower for the no-use (mean=6.99) and cannabis-use (mean=8.10) than narcotic-use (mean=10.65) and concurrent-use (mean=11.93) cohorts. Narcotic-use reported a significantly lower rating of their overall health state (mean=50.03) than cannabis-use (mean=60.50, p=0.011) and no-use (mean=61.89, p=0.001).

Patients with pre-operative narcotic-use or concurrent use of narcotics and cannabis experienced higher levels of disability, pain and depressive symptoms and worse mental health functioning compared to patients with no cannabis/narcotic use and cannabis only use. To the best of our knowledge, this is the first and largest study to examine the use of cannabis amongst Canadian patients with spinal pathology. This observational study lays the groundwork to better understand the potential benefits of adding cannabinoids to control pain in patients waiting for spine surgery. This will allow to refine recommendations about cannabis use for these patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 2 - 2
1 Dec 2022
Schneider P Bergeron S Liew A Kreder H Berry, G
Full Access

Fractures of the humeral diaphysis occur in a bimodal distribution and represent 3-5% of all fractures. Presently, the standard treatment of isolated humeral diaphyseal fractures is nonoperative care using splints, braces, and slings. Recent data has questioned the effectiveness of this strategy in ensuring fracture healing and optimal patient function. The primary objective of this randomized controlled trial (RCT) was to assess whether operative treatment of humeral shaft fractures with a plate and screw construct provides a better functional outcome than nonoperative treatment. Secondary objectives compared union rates and both clinical and patient-reported outcomes.

Eligible patients with an isolated, closed humeral diaphyseal fracture were randomized to either nonoperative care (initial sugar-tong splint, followed by functional coaptation brace) or open reduction and internal fixation (ORIF; plate and screw construct). The primary outcome measure was the Disability Shoulder, Arm, Hand (DASH) score assessed at 2-, 6-, 16-, 24-, and 52-weeks. Secondary outcomes included the Short Musculoskeletal Functional Assessment (SMFA), the Constant Shoulder Score, range of motion (ROM), and radiographic parameters. Independent samples t-tests and Chi-squared analyses were used to compare treatment groups. The DASH, SMFA, and Constant Score were modelled over time using a multiple variable mixed effects model.

A total of 180 patients were randomized, with 168 included in the final analysis. There were 84 patients treated nonoperatively and 84 treated with ORIF. There was no significant difference between the two treatment groups for age (mean = 45.4 years, SD 16.5 for nonoperative group and 41.7, SD 17.2 years for ORIF group; p=0.16), sex (38.1% female in nonoperative group and 39.3% female in ORIF group; p=0.87), body mass index (mean = 27.8, SD 8.7 for nonoperative group and 27.2, SD 6.2 for ORIF group; p=0.64), or smoking status (p=0.74). There was a significant improvement in the DASH scores at 6 weeks in the ORIF group compared to the nonoperative group (mean=33.8, SD 21.2 in the ORIF group vs. mean=56.5, SD=21.1 in the nonoperative group; p < 0 .0001). At 4 months, the DASH scores were also significantly better in the ORIF group (mean=21.6, SD=19.7 in the ORIF group vs. mean=31.6, SD=24.6 in the nonoperative group; p=0.009. However, there was no difference in DASH scores at 12-month follow-up between the groups (mean=8.8,SD=10.9 vs. mean=11.0, SD=16.9 in the nonoperative group; p=0.39). Males had improved DASH scores at all timepoints compared with females. There was significantly quicker time to union (p=0.016) and improved position (p < 0 .001) in the ORIF group. There were 13 (15.5%) nonunions in the nonoperative group and four (4.7%) combined superficial and deep infections in the ORIF group. There were seven radial nerve palsies in the nonoperative group and five (a single iatrogenic) radial nerve palsies in the ORIF group.

This large RCT comparing operative and nonoperative treatment of humeral diaphyseal fractures found significantly improved functional outcome scores in patients treated surgically at 6 weeks and 4 months. However, the early functional improvement did not persist at the 12-month follow-up. There was a 15.5% nonunion rate, which required surgical intervention, in the nonoperative group and a similar radial nerve palsy rate between groups.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 88 - 88
1 Dec 2022
Del Papa J Champagne A Shah A Toor J Larouche J Nousiainen M Mann S
Full Access

The 2020-2021 Canadian Residency Matching Service (CaRMS) match year was altered on an unprecedented scale. Visiting electives were cancelled at a national level, and the CaRMS interview tour was moved to a virtual model. These changes posed a significant challenge to both prospective students and program directors (PDs), requiring each party to employ alternative strategies to distinguish themselves throughout the match process. For a variety of reasons, including a decline in applicant interest secondary to reduced job prospects, the field of orthopaedic surgery was identified as vulnerable to many of these changes, creating a window of opportunity to evaluate their impacts on students and recruiting residency programs.

This longitudinal survey study was disseminated to match-year medical students (3rd and 4th year) with an interest in orthopaedic surgery, as well as orthopaedic surgery program directors. Responses to the survey were collected using an electronic form designed in Qualtrics (Qualtrics, 2021, Provo, Utah, USA). Students were contacted through social media posts, as well as by snowball sampling methods through appropriate medical student leadership intermediates. The survey was disseminated to all 17 orthopedic surgery program directors in Canada.

A pre-match and post-match iteration of this survey were designed to identify whether expectations differed from reality regarding the effect of the COVID-19 pandemic on the CaRMS match 2020-2021 process. A similar package was disseminated to Canadian orthopaedic surgery program directors pre-match, with an option to opt-in for a post-match survey follow-up. This survey had a focus on program directors’ opinions of various novel communication, recruitment, and assessment strategies, in the wake of the COVID-19 pandemic.

Students’ responses to the loss of visiting electives were negative. Despite a reduction in financial stress associated with reduced need to travel (p=0.001), this was identified as a core component of the clerkship experience. In the case of virtual interviews, students’ initial trepidation pre-CaRMS turned into a positive outlook post-CaRMS (significant improvement, p=0.009) indicating an overall satisfaction with the virtual interview format, despite some concerns about a reduction in their capacity to network. Program directors and selection committee faculty also felt positively about the virtual interview format. Both students and program directors were overwhelmingly positive about virtual events put on by both school programs and student-led initiatives to complement the CaRMS tour.

CaRMS was initially developed to facilitate the matching process for both students and programs alike. We hope to continue this tradition of student-led and student-informed change by providing three evidence-based recommendations. First, visiting electives should not be discontinued in future iterations of CaRMS if at all possible. Second, virtual interviews should be considered as an alternative approach to the CaRMS interview tour moving forward. And third, ongoing virtual events should be associated with a centralized platform from which programs can easily communicate virtual sessions to their target audience.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 75 - 75
1 Dec 2022
Rousseau-Saine A Kerslake S Hiemstra LA
Full Access

Recurrent patellar instability is a common problem and there are multiple demographic and pathoanatomic risk factors that predispose patients to dislocating their patella. The most common of these is trochlear dysplasia. In cases of severe trochlear dysplasia associated with patellar instability, a sulcus deepening trochleoplasty combined with a medial patellofemoral ligament reconstruction (MPFLR) may be indicated. Unaddressed trochlear pathology has been associated with failure and poor post-operative outcomes after stabilization. The purpose of this study is to report the clinical outcome of patients having undergone a trochleoplasty and MPFLR for recurrent lateral patellofemoral instability in the setting of high-grade trochlear dysplasia at a mean of 2 years follow-up.

A prospectively collected database was used to identify 46 patients (14 bilateral) who underwent a combined primary MPFLR and trochleoplasty for recurrent patellar instability with high-grade trochlear dysplasia between August 2013 and July 2021. A single surgeon performed a thin flap trochleoplasty using a lateral para-patellar approach with lateral retinaculum lengthening in all 60 cases. A tibial tubercle osteotomy (TTO) was performed concomitantly in seven knees (11.7%) and the MPFLR was performed with a gracilis tendon autograft in 22%, an allograft tendon in 27% and a quadriceps tendon autograft in 57% of cases. Patients were assessed post-operatively at three weeks and three, six, 12 and 24 months. The primary outcome was the Banff Patellar Instability Instrument 2.0 (BPII 2.0) and secondary outcomes were incidence of recurrent instability, complications and reoperations.

The mean age was 22.2 years (range, 13 to 45), 76.7% of patients were female, the mean BMI was 25.03 and the prevalence of a positive Beighton score (>4/9) was 40%. The mean follow-up was 24.3 (range, 6 to 67.7) months and only one patient was lost to follow-up before one year post-operatively. The BPII 2.0 improved significantly from a mean of 27.3 pre-operatively to 61.1 at six months (p < 0 .01) and further slight improvement to a mean of 62.1 at 12 months and 65.6 at 24 months post-operatively. Only one patient (1.6%) experienced a single event of subluxation without frank dislocation at nine months. There were three reoperations (5%): one for removal of the TTO screws and prominent chondral nail, one for second-look arthroscopy for persistent J-sign and one for mechanical symptoms associated with overgrowth of a lateral condyle cartilage repair with a bioscaffold. There were no other complications.

In this patient cohort, combined MPFLR and trochleoplasty for recurrent patellar instability with severe trochlear dysplasia led to significant improvement of patient reported outcome scores and no recurrence of patellar dislocation at a mean of 2 years. Furthermore, in this series the procedure demonstrated a low rate (5%) of complications and reoperations.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 76 - 76
1 Dec 2022
Kruse C Axelrod D Johal H Al-Mohrej O Daniel R
Full Access

Despite the routine use of systemic antibiotic prophylaxis, postoperative infection following fracture surgery remains a persistent issue with substantial morbidity. The use of additional local antibiotic prophylaxis may have a protective effect and some orthopaedic surgeons have adopted their use in recent years, despite limited evidence of its beneficial effect. The purpose of this systematic review and meta-analysis was to evaluate the current literature regarding the effect of prophylactic local antibiotics on the rate of infection in fracture surgery in both open and closed fractures.

A comprehensive search of Medline, EMBASE, and PubMed was performed. Cohort studies were eligible if they investigated the effect on infection rate of additional local antibiotic prophylaxis compared with systemic prophylaxis alone following fracture surgery. The data were pooled in a meta-analysis.

In total, four randomized controlled trials and 11 retrospective cohort studies with a total of 6161 fractures from various anatomical locations were eligible for inclusion. The majority of the included studies were Level 3 evidence and had a moderate risk of bias. When all fractures were pooled, the risk of infection was significantly reduced when local antibiotics were applied compared with the control group receiving systemic prophylaxis only (OR = 0.39; 95%CI: 0.26 to 0.53, P < 0.001). In particular, there was a significant reduction in deep infections (OR = 0.59; 95%CI: 0.38 to 0.91, P = 0.017). The beneficial effect of local antibiotics for preventing total infection was seen in both open fractures (OR = 0.35; 95%CI: 0.23 to 0.53, P < 0.001) and closed fractures (OR = 0.58; 95%CI: 0.35 to 0.95, P = 0.029) when analyzed separately.

This meta-analysis suggests a significant risk reduction for postoperative infection following fracture surgery when local antibiotics were added to standard systemic prophylaxis, with a protective effect present in both open and closed fractures.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 91 - 91
1 Dec 2022
Abbas A Toor J Saleh I Abouali J Wong PKC Chan T Sarhangian V
Full Access

Most cost containment efforts in public health systems have focused on regulating the use of hospital resources, especially operative time. As such, attempting to maximize the efficiency of limited operative time is important. Typically, hospital operating room (OR) scheduling of time is performed in two tiers: 1) master surgical scheduling (annual allocation of time between surgical services and surgeons) and 2) daily scheduling (a surgeon's selection of cases per operative day). Master surgical scheduling is based on a hospital's annual case mix and depends on the annual throughput rate per case type. This throughput rate depends on the efficiency of surgeons’ daily scheduling. However, daily scheduling is predominantly performed manually, which requires that the human planner simultaneously reasons about unknowns such as case-specific length-of-surgery and variability while attempting to maximize throughput. This often leads to OR overtime and likely sub-optimal throughput rate. In contrast, scheduling using mathematical and optimization methods can produce maximum systems efficiency, and is extensively used in the business world. As such, the purpose of our study was to compare the efficiency of 1) manual and 2) optimized OR scheduling at an academic-affiliated community hospital representative of most North American centres.

Historic OR data was collected over a four year period for seven surgeons. The actual scheduling, surgical duration, overtime and number of OR days were extracted. This data was first configured to represent the historic manual scheduling process. Following this, the data was then used as the input to an integer linear programming model with the goal of determining the minimum number of OR days to complete the same number of cases while not exceeding the historic overtime values. Parameters included the use of a different quantile for each case type's surgical duration in order to ensure a schedule within five percent of the historic overtime value per OR day.

All surgeons saw a median 10% (range: 9.2% to 18.3%) reduction in the number of OR days needed to complete their annual case-load compared to their historical scheduling practices. Meanwhile, the OR overtime varied by a maximum of 5%. The daily OR configurations differed from historic configurations in 87% of cases. In addition, the number of configurations per surgeon was reduced from an average of six to four.

Our study demonstrates a significant increase in OR throughput rate (10%) with no change in operative time required. This has considerable implications in terms of cost reduction, surgical wait lists and surgeon satisfaction. A limitation of this study was that the potential gains are based on the efficiency of the pre-existing manual scheduling at our hospital. However, given the range of scenarios tested, number of surgeons included and the similarity of our hospital size and configuration to the majority of North American hospitals with an orthopedic service, these results are generalizable. Further optimization may be achieved by taking into account factors that could predict case duration such as surgeon experience, patients characteristics, and institutional attributes via machine learning.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 80 - 80
1 Dec 2022
Reeves J Spangenberg G Elwell J Stewart B Vanasse T Roche C Langohr GD Faber KJ
Full Access

Shoulder arthroplasty is effective at restoring function and relieving pain in patients suffering from glenohumeral arthritis; however, cortex thinning has been significantly associated with larger press-fit stems (fill ratio = 0.57 vs 0.48; P = 0.013)1. Additionally, excessively stiff implant-bone constructs are considered undesirable, as high initial stiffness of rigid fracture fixation implants has been related to premature loosening and an ultimate failure of the implant-bone interface2. Consequently, one objective which has driven the evolution of humeral stem design has been the reduction of stress-shielding induced bone resorption; this in-part has led to the introduction of short stems, which rely on metaphyseal fixation. However, the selection of short stem diametral (i.e., thickness) sizing remains subjective, and its impact on the resulting stem-bone construct stiffness has yet to be quantified.

Eight paired cadaveric humeri (age = 75±15 years) were reconstructed with surgeon selected ‘standard’ sized and 2mm ‘oversized’ short-stemmed implants. Standard stem sizing was based on a haptic assessment of stem and broach stability per typical surgical practice. Anteroposterior radiographs were taken, and the metaphyseal and diaphyseal fill ratios were quantified. Each humerus was then potted in polymethyl methacrylate bone cement and subjected to 2000 cycles of compressive loading representing 90º forward flexion to simulate postoperative seating. Following this, a custom 3D printed metal implant adapter was affixed to the stem, which allowed for compressive loading in-line with the stem axis (Fig.1). Each stem was then forced to subside by 5mm at a rate of 1mm/min, from which the compressive stiffness of the stem-bone construct was assessed. The bone-implant construct stiffness was quantified as the slope of the linear portion of the resulting force-displacement curves.

The metaphyseal and diaphyseal fill ratios were 0.50±0.10 and 0.45±0.07 for the standard sized stems and 0.50±0.06 and 0.52±0.06 for the oversized stems, respectively. Neither was found to correlate significantly with the stem-bone construct stiffness measure (metaphysis: P = 0.259, diaphysis: P = 0.529); however, the diaphyseal fill ratio was significantly different between standard and oversized stems (P < 0.001, Power = 1.0). Increasing the stem size by 2mm had a significant impact on the stiffness of the stem-bone construct (P = 0.003, Power = 0.971; Fig.2). Stem oversizing yielded a construct stiffness of −741±243N/mm; more than double that of the standard stems, which was −334±120N/mm.

The fill ratios reported in the present investigation match well with those of a finite element assessment of oversizing short humeral stems3. This work complements that investigation's conclusion, that small reductions in diaphyseal fill ratio may reduce the likelihood of stress shielding, by also demonstrating that oversizing stems by 2mm dramatically increases the stiffness of the resulting implant-bone construct, as stiffer implants have been associated with decreased bone stimulus4 and premature loosening2. The present findings suggest that even a small, 2mm, variation in the thickness of short stem humeral components can have a marked influence on the resulting stiffness of the implant-bone construct. This highlights the need for more objective intraoperative methods for selecting stem size to provide guidelines for appropriate diametral sizing.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 83 - 83
1 Dec 2022
Bornes T Kubik J Klinger C Altintas B Dziadosz D Ricci W
Full Access

Tibial plateau fracture reduction involves restoration of alignment and articular congruity. Restorations of sagittal alignment (tibial slope) of medial and lateral condyles of the tibial plateau are independent of each other in the fracture setting. Limited independent assessment of medial and lateral tibial plateau sagittal alignment has been performed to date. Our objective was to characterize medial and lateral tibial slopes using fluoroscopy and to correlate X-ray and CT findings.

Phase One: Eight cadaveric knees were mounted in extension. C-arm fluoroscopy was used to acquire an AP image and the C-arm was adjusted in the sagittal plane from 15° of cephalad tilt to 15 ° of caudad tilt with images captured at 0.5° increments. The “perfect AP” angle, defined as the angle that most accurately profiled the articular surface, was determined for medial and lateral condyles of each tibia by five surgeons. Given that it was agreed across surgeons that more than one angle provided an adequate profile of each compartment, a range of AP angles corresponding to adequate images was recorded. Phase Two: Perfect AP angles from Phase One were projected onto sagittal CT images in Horos software in the mid-medial compartment and mid-lateral compartment to determine the precise tangent subchondral anatomic structures seen on CT to serve as dominant bony landmarks in a protocol generated for calculating medial and lateral tibial slopes on CT. Phase Three: 46 additional cadaveric knees were imaged with CT. Tibial slopes were determined in all 54 specimens.

Phase One: Based on the perfect AP angle on X-ray, the mean medial slope was 4.2°+/-2.6° posterior and mean lateral slope was 5.0°+/-3.8° posterior in eight knees. A range of AP angles was noted to adequately profile each compartment in all specimens and was noted to be wider in the lateral (3.9°+/-3.8°) than medial compartment (1.8°+/-0.7° p=0.002). Phase Two: In plateaus with a concave shape, the perfect AP angle on X-ray corresponded with a line between the superiormost edges of the anterior and posterior lips of the plateau on CT. In plateaus with a flat or convex shape, the perfect AP angle aligned with a tangent to the subchondral surface extending from center to posterior plateau on CT. Phase Three: Based on the CT protocol created in Phase Two, mean medial slope (5.2°+/-2.3° posterior) was significantly less than lateral slope (7.5°+/-3.0° posterior) in 54 knees (p<0.001). In individual specimens, the difference between medial and lateral slopes was variable, ranging from 6.8° more laterally to 3.1° more medially. In a paired comparison of right and left knees from the same cadaver, no differences were noted between sides (medial p=0.43; lateral p=0.62).

On average there is slightly more tibial slope in the lateral plateau than medial plateau (2° greater). However, individual patients may have substantially more lateral slope (up to 6.8°) or even more medial slope (up to 3.1°). Since tibial slope was similar between contralateral limbs, evaluating slope on the uninjured side provides a template for sagittal plane reduction of tibial plateau fractures.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 35 - 35
1 Dec 2022
Torkan L Bartlett K Nguyen K Bryant T Bicknell R Ploeg H
Full Access

Reverse shoulder arthroplasty (RSA) is commonly used to treat patients with rotator cuff tear arthropathy. Loosening of the glenoid component remains one of the principal modes of failure and is the main complication leading to revision. For optimal RSA implant osseointegration to occur, the micromotion between the baseplate and the bone must not exceed a threshold of 150 µm. Excess micromotion contributes to glenoid loosening. This study assessed the effects of various factors on glenoid baseplate micromotion for primary fixation of RSA.

A half-fractional factorial experiment design (2k-1) was used to assess four factors: central element type (central peg or screw), central element cortical engagement according to length (13.5 or 23.5 mm), anterior-posterior (A-P) peripheral screw type (nonlocking or locking), and bone surrogate density (10 or 25 pounds per cubic foot [pcf]). This created eight unique conditions, each repeated five times for 40 total runs. Glenoid baseplates were implanted into high- or low-density Sawbones™ rigid polyurethane (PU) foam blocks and cyclically loaded at 60 degrees for 1000 cycles (500 N compressive force range) using a custom designed loading apparatus. Micromotion at the four peripheral screw positions was recorded using linear variable displacement transducers (LVDTs). Maximum micromotion was quantified as the displacement range at the implant-PU interface, averaged over the last 10 cycles of loading.

Baseplates with short central elements that lacked cortical bone engagement generated 373% greater maximum micromotion at all peripheral screw positions compared to those with long central elements (p < 0.001). Central peg fixation generated 360% greater maximum micromotion than central screw fixation (p < 0.001). No significant effects were observed when varying A-P peripheral screw type or bone surrogate density. There were significant interactions between central element length and type (p < 0.001).

An interaction existed between central element type and level of cortical engagement. A central screw and a long central element that engaged cortical bone reduced RSA baseplate micromotion. These findings serve to inform surgical decision-making regarding baseplate fixation elements to minimize the risk of glenoid loosening and thus, the need for revision surgery.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 74 - 74
1 Dec 2022
Changoor A Suderman R Wood B Grynpas M Hurtig M Kuzyk P
Full Access

Large cartilage lesions in younger patients can be treated by fresh osteochondral allograft transplantation, a surgical technique that relies on stable initial fixation and a minimum chondrocyte viability of 70% in the donor tissue to be successful. The Missouri Osteochondral Allograft Preservation System (MOPS) may extend the time when stored osteochondral tissues remain viable. This study aimed to provide an independent evaluation of MOPS storage by evaluating chondrocyte viability, chondrocyte metabolism, and the cartilage extracellular matrix using an ovine model.

Femoral condyles from twelve female Arcott sheep (6 years, 70 ± 15 kg) were assigned to storage times of 0 (control), 14, 28, or 56 days. Sheep were assigned to standard of care [SOC, Lactated Ringer's solution, cefazolin (1 g/L), bacitracin (50,000 U/L), 4°C storage] or MOPS [proprietary media, 22-25°C storage]. Samples underwent weekly media changes. Chondrocyte viability was assessed using Calcein AM/Ethidium Homodimer and reported as percent live cells and viable cell density (VCD). Metabolism was evaluated with the Alamar blue assay and reported as Relative Fluorescent Units (RFU)/mg. Electromechanical properties were measured with the Arthro-BST, a device used to non-destructively compress cartilage and calculate a quantitative parameter (QP) that is inversely proportional to stiffness. Proteoglycan content was quantified using the dimethylmethylene blue assay of digested cartilage and distribution visualized by Safranin-O/Fast Green staining of histological sections. A two-way ANOVA and Tukey's post hoc were performed.

Compared to controls, MOPS samples had fewer live cells (p=0.0002) and lower VCD (p=0.0004) after 56 days of storage, while SOC samples had fewer live cells (p=0.0004, 28 days; p=0.0002, 56 days) and lower VCD (p=0.0002, 28 days; p=0.0001, 56 days) after both 28 and 56 days (Table 1). At 14 days, the percentage of viable cells in SOC samples were statistically the same as controls but VCD was lower (p=0.0197). Cell metabolism in MOPS samples remained the same over the study duration but SOC had lower RFU/mg after 28 (p=0.0005) and 56 (p=0.0001) days in storage compared to controls. These data show that MOPS maintained viability up to 28 days yet metabolism was sustained for 56 days, suggesting that the conditions provided by MOPS storage allowed fewer cells to achieve the same metabolic levels as fresh cartilage. Electromechanical QP measurements revealed no differences between storage methods at any individual time point. QP data could not be used to interpret changes over time because a mix of medial and lateral condyles were used and they have intrinsically different properties. Proteoglycan content in MOPS samples remained the same over time but SOC was significantly lower after 56 days (p=0.0086) compared to controls. Safranin-O/Fast Green showed proteoglycan diminished gradually beginning at the articular surface and progressing towards bone in SOC samples, while MOPS maintained proteoglycan over the study duration (Figure 1).

MOPS exhibited superior viability, metabolic activity and proteoglycan retention compared to SOC, but did not maintain viability for 56 days. Elucidating the effects of prolonged MOPS storage on cartilage properties supports efforts to increase the supply of fresh osteochondral allografts for clinical use.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 75 - 75
1 Dec 2022
Hunter J Lalone E
Full Access

Analyzing shoulder kinematics is challenging as the shoulder is comprised of a complex group of multiple highly mobile joints. Unlike at the elbow or knee which has a primary flexion/extension axis, both primary shoulder joints (glenohumeral and scapulothoracic) have a large range of motion (ROM) in all three directions. As such, there are six degrees of freedom (DoF) in the shoulder joints (three translations and three rotations), and all these parameters need to be defined to fully describe shoulder motion. Despite the importance of glenohumeral and scapulothoracic coordination, it's the glenohumeral joint that is most studied in the shoulder. Additionally, the limited research on the scapulothoracic primarily focuses on planar motion such as abduction or flexion. However, more complex motions, such as internally rotating to the back, are rarely studied despite the importance for activities of daily living. A technique for analyzing shoulder kinematics which uses 4DCT has been developed and validated and will be used to conduct analysis. The objective of this study is to characterize glenohumeral and scapulothoracic motion during active internal rotation to the back, in a healthy young population, using a novel 4DCT approach.

Eight male participants over 18 with a healthy shoulder ROM were recruited. For the dynamic scan, participants performed internal rotation to the back. For this motion, the hand starts on the abdomen and is moved around the torso up the back as far as possible, unconstrained to examine variability in motion pathway. Bone models were made from the dynamic scans and registered to neutral models, from a static scan, to calculate six DoF kinematics. The resultant kinematic pathways measured over the entire motion were used to calculate the ROM for each DoF.

Results indicate that anterior tilting is the most important DoF of the scapula, the participants all followed similar paths with low variation. Conversely, it appears that protraction/retraction of the scapula is not as important for internally rotating to the back; not only was the ROM the lowest, but the pathways had the highest variation between participants. Regarding glenohumeral motion, internal rotation was by far the DoF with the highest ROM, but there was also high variation in the pathways. Summation of ROM values revealed an average glenohumeral to scapulothoracic ratio of 1.8:1, closely matching the common 2:1 ratio other studies have measured during abduction.

Due to the unconstrained nature of the motion, the complex relationship between the glenohumeral and scapulothoracic joints leads to high variation in kinematic pathways. The shoulder has redundant degrees of freedom, the same end position can result from different joint angles and positions. Therefore, some individuals might rely more on scapular motion while others might utilize primarily humeral motion to achieve a specific movement. More analysis needs to be done to identify if any direct correlations can be drawn between scapulothoracic and glenohumeral DoF. Analyzing the kinematics of the glenohumeral and scapulothoracic joint throughout motion will further improve understanding of shoulder mechanics and future work plans to examine differences with age.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 60 - 60
1 Dec 2022
Martin RK Wastvedt S Pareek A Persson A Visnes H Fenstad AM Moatshe G Wolfson J Lind M Engebretsen L
Full Access

External validation of machine learning predictive models is achieved through evaluation of model performance on different groups of patients than were used for algorithm development. This important step is uncommonly performed, inhibiting clinical translation of newly developed models. Recently, machine learning was used to develop a tool that can quantify revision risk for a patient undergoing primary anterior cruciate ligament (ACL) reconstruction (https://swastvedt.shinyapps.io/calculator_rev/). The source of data included nearly 25,000 patients with primary ACL reconstruction recorded in the Norwegian Knee Ligament Register (NKLR). The result was a well-calibrated tool capable of predicting revision risk one, two, and five years after primary ACL reconstruction with moderate accuracy. The purpose of this study was to determine the external validity of the NKLR model by assessing algorithm performance when applied to patients from the Danish Knee Ligament Registry (DKLR).

The primary outcome measure of the NKLR model was probability of revision ACL reconstruction within 1, 2, and/or 5 years. For the index study, 24 total predictor variables in the NKLR were included and the models eliminated variables which did not significantly improve prediction ability - without sacrificing accuracy. The result was a well calibrated algorithm developed using the Cox Lasso model that only required five variables (out of the original 24) for outcome prediction. For this external validation study, all DKLR patients with complete data for the five variables required for NKLR prediction were included. The five variables were: graft choice, femur fixation device, Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life subscale score at surgery, years from injury to surgery, and age at surgery. Predicted revision probabilities were calculated for all DKLR patients. The model performance was assessed using the same metrics as the NKLR study: concordance and calibration.

In total, 10,922 DKLR patients were included for analysis. Average follow-up time or time-to-revision was 8.4 (±4.3) years and overall revision rate was 6.9%. Surgical technique trends (i.e., graft choice and fixation devices) and injury characteristics (i.e., concomitant meniscus and cartilage pathology) were dissimilar between registries. The model produced similar concordance when applied to the DKLR population compared to the original NKLR test data (DKLR: 0.68; NKLR: 0.68-0.69). Calibration was poorer for the DKLR population at one and five years post primary surgery but similar to the NKLR at two years.

The NKLR machine learning algorithm demonstrated similar performance when applied to patients from the DKLR, suggesting that it is valid for application outside of the initial patient population. This represents the first machine learning model for predicting revision ACL reconstruction that has been externally validated. Clinicians can use this in-clinic calculator to estimate revision risk at a patient specific level when discussing outcome expectations pre-operatively. While encouraging, it should be noted that the performance of the model on patients undergoing ACL reconstruction outside of Scandinavia remains unknown.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 80 - 80
1 Dec 2022
Nauth A Dehghan N Schemitsch C Schemitsch EH Jenkinson R Vicente M McKee MD
Full Access

There has been a substantial increase in the surgical treatment of unstable chest wall injuries recently. While a variety of fixation methods exist, most surgeons have used plate and screw fixation. Rib-specific locking plate systems are available, however evidence supporting their use over less-expensive, conventional plate systems (such as pelvic reconstruction plates) is lacking. We sought to address this by comparing outcomes between locking plates and non-locking plates in a cohort of patients from a prior randomized trial who received surgical stabilization of their unstable chest wall injury.

We used data from the surgical group of a previous multi-centred, prospective, randomized controlled trial comparing surgical fixation of acute, unstable chest wall injuries to non-operative management. In this substudy, our primary outcome was hardware-related complications and re-operation. Secondary outcomes included ventilator free days (VFDs) in the first 28 days following injury, length of ICU and hospital stay, and general health outcomes (SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores). Categorical variables are reported as frequency counts and percentages and the two groups were compared using Fisher's Exact test. Continuous data are reported as median and interquartile range and the two groups were compared using the Wilcoxon rank-sum test.

From the original cohort of 207 patients, 108 had been treated surgically and had data available on the type of plate construct used. Fifty-nine patients (55%) had received fixation with non-locking plates (primarily 3.5 or 2.7 mm pelvic reconstruction plates) and 49 (45%) had received fixation with locking plates (primarily rib-specific locking plates). The two groups were similar in regard to baseline and injury characteristics. In the non-locking group, 15% of patients (9/59) had evidence of hardware loosening versus 4% (2/49 patients) in the locking group (p = 0.1). The rate of re-operation for hardware complications was 3% in the non-locking group versus 0% in the locking group (p = 0.5). No patients in either group required revision fixation for loss of reduction or nonunion. There were no differences between the groups with regard to VFDs (26.3 [19.6 – 28] vs. 27.3 [18.3 – 28], p = 0.83), length of ICU stay (6.5 [2.0 – 13.1] vs 4.1 [0 – 11], p = 0.12), length of hospital stay (17 [10 – 32] vs. 17 [10 – 24], p = 0.94) or SF-36 PCS (40.9 [33.6 – 51.0] vs 43.4 [34.1 – 49.6], p = 0.93) or MCS scores (47.8 [36.9 – 57.9] vs 46.9 [40.5 – 57.4], p = 0.95).

We found no statistically significant differences in outcomes between patients who received surgical stabilization of their unstable chest wall injury when comparing non-locking plates versus locking plates. However, the rate of hardware loosening was nearly 4 times higher in the non-locking plate group and trended towards statistical significance, although re-operation related to this was less frequent. This finding is not surprising, given the inherent challenges of rib fixation including thin bones, comminution, potential osteopenia and a post-operative environment of constant motion. We believe that the increased cost of locking plate fixation in this setting is likely justifiable given these findings.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 23 - 23
1 Dec 2022
Innmann MM Verhaegen J Reichel F Schaper B Merle C Grammatopoulos G
Full Access

The presence of hip osteoarthritis is associated with abnormal spinopelvic characteristics. This study aims to determine whether the pre-operative, pathological spinopelvic characteristics “normalize” at 1-year post-THA.

This is a prospective, longitudinal, case-control matched cohort study. Forty-seven patients underwent pre- and post- (at one-year) THA assessments. This group was matched (age, sex, BMI) with 47 controls/volunteers with well-functioning hips. All participants underwent clinical and radiographic assessments including lateral radiographs in standing, upright-seated and deep-flexed-seated positions. Spinopelvic characteristics included change in lumbar lordosis (ΔLL), pelvic tilt (ΔPT) and hip flexion (pelvic-femoral angle, ΔPFA) when moving from the standing to each of the seated positions. Spinopelvic hypermobility was defined as ΔPT>30° between standing and upright-seated positions.

Pre-THA, patients illustrated less hip flexion (ΔPFA −54.8°±17.1° vs. −68.5°± 9.5°, p<0.001), greater pelvic tilt (ΔPT 22.0°±13.5° vs. 12.7°±8.1°, p<0.001) and greater lumbar movements (ΔLL −22.7°±15.5° vs. −15.4°±10.9°, p=0.015) transitioning from standing to upright-seated. Post-THA, these differences were no longer present (ΔPFApost −65.8°±12.5°, p=0.256; ΔPTpost 14.3°±9.5°, p=0.429; ΔLLpost −15.3°±10.6°, p=0.966). The higher prevalence of pre-operative spinopelvic hypermobility in patients compared to controls (21.3% vs. 0.0%; p=0.009), was not longer present post-THA (6.4% vs. 0.0%; p=0.194). Similar results were found moving from standing to deep-seated position post-THA.

Pre-operative, spinopelvic characteristics that contribute to abnormal mechanics can normalize post-THA following improvement in hip flexion. This leads to patients having the expected hip-, pelvic- and spinal flexion as per demographically-matched controls, thus potentially eliminating abnormal mechanics that contribute to the development/exacerbation of hip-spine syndrome.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 8 - 8
1 Dec 2022
Okamoto T Glaris Z Goetz T
Full Access

Pathologies such as Scapho-Lunate Advanced Collapse (SLAC), Scaphoid Non-union Advanced Collapse (SNAC) and Kienbock's disease can lead to arthritis in the wrist. Depending on the articular surfaces that are involved, motion preserving surgical procedures can be performed. Proximal Row Carpectomy (PRC) and Four Corner Fusion (4CF) are tried and tested surgical options. However, prospective studies comparing the two methods looking at sufficient sample sizes are limited in the literature.

The purpose of this study was to prospectively compare the early results of PRC vs 4CF performed in a single centre.

Patients with wrist arthritis were prospectively enrolled (2015 to 2021) in a single centre in Vancouver, Canada. Thirty-six patients and a total of 39 wrists underwent either a PRC (n=18) or 4CF (n=21) according to pre-operative clinical, radiographical, and intra-operative assessment. Patient-Rated Wrist Evaluation (PRWE) scores were obtained preoperatively, as well as at six months and one year post operatively. Secondary outcomes were range of motion (ROM) of the wrist, grip strength, reoperation and complication rates. Statistical significance was set at p=0.05

Respectively for PRC and 4CF, the average PRWE scores at baseline were 61.64 (SD=19.62) and 63.67 (SD=20.85). There was significant improvement at the six-month mark to 38.81 (SD=22.95) (p=0.031) and 41.33 (SD=26.61) (p=0.007), then further improvement at the 12month mark to 33.11 (SD=23.42) (p=0.007) and 36.29 (SD=27.25) (p=0.002).

There was no statistical difference between the two groups at any time point.

Regarding ROM, statistical difference was seen in pronation for the PRC group at the 6month mark from an average of 72.18 deg to 61.56 deg and in flexion at the 12 month mark from 47.89 deg to 33.50 deg. All other parameters did not show statistically significant difference post operatively.

For ROM of the 4CF group, only flexion at the 12month mark showed statistically significant change from an average of 48.81 deg to 38.03 deg.

There was no statistical difference in pre-operative ROM between the two groups.

One patient in the 4CF group required a revision for delayed union, and three patients ended up with ulnar sided wrist pain.

Patients undergoing PRC and 4CF showed significant improvement in post operative PRWE scores, this reflects existing literature. For 4CF care must be taken to minimise ulnar sided wrist pain by relatively shortening the unar sided carpal column mass.

ROM analysis showed that patients lost some wrist flexion ROM post-operatively at the 12month mark with both PRC and 4CF. However, other ROM parameters were unchanged


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 9 - 9
1 Dec 2022
Glaris Z Okamoto T Goetz T
Full Access

SARS-CoV-2 emerged in Wuhan, China in December 2019 causing pneumonia and resulting in a pandemic, commonly known as COVID-19. This pandemic led to significant changes to our daily lives due to restrictions, such as social distancing, quarantining, stay at home orders and closure of restaurants and shops among other things. The psychological effects of this uncertainty as well as of these changes to our lives have been shown to be significant. This study is a prospective study investigating the mental effects of the pandemic on hand and wrist patients seen in our clinic during this pandemic.

A prospective database on wrist pain was used to identify patients seen in our hand clinic from January 1, 2018 to December 10, 2021. All participants had been diagnosed with either radial sided wrist pain or ulnar side wrist pain. The Center for Epidemiological Studies Depression (CES-D) Scale was used to assess the mental health of our participants before and during this pandemic. An independent samples t-test was used to compare the scores of the 2 groups.

A total of 437 CES-D questionnaires were collected during this period. 118 of them belonging to the pandemic group and 319 to the pre-pandemic group. A difference (p < 0 .05) in the CES-D score was observed between the pre-pandemic and during pandemic groups. The mean score for the pre-pandemic group was found to be 9.23 (8.94) and 12.81 (11.45) for the pandemic group. However, despite the increase in score, it didn't exceed the cut off score of 16 or greater used to assess depression.

Our results indicate that there was a slight increase in score for depression in hand and wrist patients, but not above the cut off level of 16 to be of a significant risk for depression. Other global studies have shown an increase in depression in the general public. Our mild results might be attributed to the fact that British Columbia did not implement severe restrictions compared to other countries or regions, i.e no stay at home orders. Additionally, our study population was skewed and included more middle age and older patients compared to younger ones and age might be a factor in keeping the score down.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 27 - 27
1 Dec 2022
Falsetto A Bohm E Wood G
Full Access

Recent registry data from around the world has strongly suggested that using cemented hip hemiarthroplasty has lower revision rates compared to cementless hip hemiarthroplasty for acute femoral neck hip fractures. The adoption of using cemented hemiarthroplasty for hip fracture has been slow as many surgeons continue to use uncemented stems. One of the reasons is that surgeons feel more comfortable with uncemented hemiarthroplasty as they have used it routinely. The purpose of this study is to compare the difference in revision rates of cemented and cementless hemiarthroplasty and stratify the risk by surgeon experience. By using a surgeons annual volume of Total Hip Replacements performed as an indicator for surgeon experience. The Canadian Joint Replacement Registry Database was used to collect and compare the outcomes to report on the revision rates based on surgeon volume.

This is a large Canadian Registry Study where 68447 patients were identified for having a hip hemiarthroplasty from 2012-2020. This is a retrospective cohort study, identifying patients that had cementless or cemented hip hemiarthroplasty. The surgeons who performed the procedures were linked to the procedure Total Hip Replacement. Individuals were categorized as experienced hip surgeons or not based on whether they performed 50 hip replacements a year. Identifying high volume surgeon (>50 cases/year) and low volume (<50 cases/year) surgeons. Hazard ratios adjusted for age and sex were performed for risk of revision over this 8-year span. A p-value <0.05 was deemed significant.

For high volume surgeons, cementless fixation had a higher revision risk than cemented fixation, HR 1.29 (1.05-1.56), p=0.017. This pattern was similar for low volume surgeons, with cementless fixation having a higher revision risk than cemented fixation, HR 1.37 (1.11-1.70) p=0.004 We could not detect a difference in revision risk for cemented fixation between low volume and high volume surgeons; at 0-1.5 years the HR was 0.96 (0.72-1.28) p=0.786, and at 1.5+ years the HR was 1.61 (0.83-3.11) p=0.159. Similarly, we could not detect a difference in revision risk for cementless fixation between low volume and high volume surgeons, HR 1.11 (0.96-1.29) p=0.161

Using large registry data, cemented hip hemiarthroplasty has a significant lower revision rate than the use of cementless stems even when surgeons are stratified to high and low volume. Low volume surgeons who use uncemented prostheses have the highest rate of revision. The low volume hip surgeon who cements has a lower revision rate than the high volume cementless surgeon. The results of this study should help to guide surgeons that no matter the level of experience, using a cemented hip hemiarthroplasty for acute femoral neck fracture is the safest option. That high volume surgeons who perform cementless hemiarthroplasty are not immune to having revisions due to their technique. Increased training and education should be offered to surgeons to improve comfort when using this technique.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 11 - 11
1 Dec 2022
Upasani V Bomar J Fitzgerald R Schupper A Kelley S
Full Access

The Pavlik harness (PH) is commonly used to treat infantile dislocated hips. Variability exists in the duration of brace treatment after successful reduction of the dislocated hip. In this study we evaluate the effect of prescribed time in brace on acetabular index (AI) at two years of age using a prospective, international, multicenter database.

We retrospectively studied prospectively enrolled infants with at least one dislocated hip that were initially treated with a PH and had a recorded AI at two-year follow-up. Subjects were treated at one of two institutions. Institution 1 used the PH until they observed normal radiographic acetabular development. Institution 2 followed a structured 12-week brace treatment protocol. Hip dislocation was defined as less than 30% femoral head coverage at rest on the pre-treatment ultrasound or IHDI grade III or IV on the pre-treatment radiograph.

Fifty-three hips met our inclusion criteria. Hips from Institution 1 were treated with a brace 3x longer than hips from institution 2 (adjusted mean 8.9±1.3 months vs 2.6±0.2 months)(p < 0 .001). Institution 1 had an 88% success rate and institution 2 had an 85% success rate at achieving hip reduction (p=0.735). At 2-year follow-up, we observed no significant difference in AI between Institution 1 (adjusted mean 25.6±0.9˚) compared to Institution 2 (adjusted mean 23.5±0.8˚) (p=0.1). However, 19% of patients from Institution 1 and 44% of patients from Institution 2 were at or below the 50th percentile of previously published age- and sex- matched AI normal data (p=0.049). Also, 27% (7/26) of hips from Institution 1 had significant acetabular dysplasia, compared to a 22% (6/27) from Institution 2 (p=0.691). We found no correlation between age at initiation of bracing and AI at 2-year follow-up (p=0.071).

Our findings suggest that prolonged brace treatment does not result in improved acetabular index at age two years. Hips treated at Institution 1 had the same AI at age two years as hips treated at Institution 2, while spending about 1/3 the amount of time in a brace. We recommend close follow-up for all children treated for dislocated hips, as ~1/4 of infants had acetabular index measurements at or above the 90th percentile of normal. Continued follow-up of this prospective cohort will be critical to determine how many children require acetabular procedures during childhood. The PH brace can successfully treat dislocated infant hips, however, prolonged brace treatment was not found to result in improved acetabular development at two-year follow-up.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 14 - 14
1 Dec 2022
Tarchala M Grant S Bradley C Camp M Matava C Kelley S
Full Access

In response to the COVID-19 pandemic public health measures were implemented to limit virus spread. After initial implementation of a province-wide lockdown (Stage 1), there followed a sequential ease of restrictions through Stages 2 and 3 over a 6-month period from March to September 2020 (Table 1). We aimed to determine the impact of COVID-19 public health measures on the epidemiology of operative paediatric orthopaedic trauma and to determine differential effects of each stage of lockdown.

A retrospective cohort study was performed comparing all emergency department (ED) visits for musculoskeletal trauma and operatively treated orthopaedic trauma cases at a Level-1 paediatric trauma center during Mar-Sep 2020 (pandemic), compared with Mar-Sep 2019 (pre-pandemic). All operative cases were analyzed based on injury severity, mechanism of injury (MOI) and anatomic location (AL). Comparisons between groups were assessed using chi-square testing for categorical variables, and student t-tests and Fisher's exact tests for continuous variables.

During the pandemic period, ED visits for orthopaedic trauma decreased compared to pre-pandemic levels by 23% (1370 vs 1790 patients) and operative treatment decreased by 28% (283 vs 391 patients). There was a significant decrease in the number of operative cases per day in lockdown Stage 1 (1.25 pandemic vs 1.90 pre- pandemic; p < 0 .001) and Stage 2 (1.65 pandemic vs 3.03 pre-pandemic; p< 0.001) but no difference in operative case number during Stage 3 (2.18 pandemic vs 2.45 pre-pandemic; p=0.35). Significant differences were found in MOI and AL during Stage 1 (p < 0 .001) and Stage 2 (p < 0 .001) compared to pre-pandemic. During Stage 1 and 2, playground injuries decreased by 95% and 82%, respectively; sports injuries decreased by 79% and 13%, and trampoline injuries decreased 44% and 43%, compared to pre-pandemic. However, self-propelled transit injuries (bicycles/skateboards) increased during Stage 1 and Stage 2 by 67% and 28%, respectively compared to pre- pandemic. During lockdown Stage 3 there were no differences in MOI nor AL. There were no significant differences in injury severity in any lockdown stage compared to pre-pandemic.

COVID-19 lockdown measures significantly reduced the burden of operative paediatric orthopaedic trauma. Differences in volume, mechanism and pattern of injuries varied by lockdown stage offering evidence of the burden of operative trauma related to specific childhood activities.

These findings will assist health systems planning for future pandemics and suggest that improvements in safety of playgrounds and self-propelled transit are important in reducing severe childhood injury requiring operative intervention.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 32 - 32
1 Dec 2022
Fransen B Bengoa F Neufeld M Sheridan G Garbuz D Howard L
Full Access

With the introduction of highly crosslinked polyethylene (HXLPE) in total hip arthroplasty (THA), orthopaedic surgeons have moved towards using larger femoral heads at the cost of thinner liners to decrease the risk of instability. Several short and mid-term studies have shown minimal liner wear with the use HXLPE liners, but the safety of using thinner HXPLE liners to maximize femoral head size remains uncertain and concerns that this may lead to premature failure exist. Our objective was to analyze the outcomes for primary THA done with HXLPE liners in patients who have a 36-mm head or larger and a cup of 52-mm or smaller, with a minimum of 10-year follow-up. Additionally, linear and volumetric wear rates of the HXLPE were evaluated in those with a minimum of seven-year follow-up. We hypothesized that there would be minimal wear and good clinical outcome.

Between 2000 and 2010, we retrospectively identified 55 patients that underwent a primary THA performed in a high-volume single tertiary referral center using HXLPE liners with 36-mm or larger heads in cups with an outer diameter of or 52-mm or smaller. Patient characteristics, implant details including liner thickness, death, complications, and all cause revisions were recorded. Patients that had a minimum radiographic follow-up of seven years were assessed radiographically for linear and volumetric wear. Wear was calculated using ROMAN, a validated open-source software by two independent researchers on anteroposterior X-rays of the pelvis.

A total of 55 patients were identified and included, with a mean age of 74.8 (range 38.67 - 95.9) years and a mean BMI of 28.98 (range 18.87 - 63-68). Fifty-one (94.4%) of patients were female. Twenty-six (47.7%) patients died during the follow-up period. Three patients were revised, none for liner wear, fracture or dissociation. Twenty-two patients had a radiographic follow-up of minimum seven years (mean 9.9 years, min-max 7.5 –13.7) and were included in the long-term radiographic analysis. Liner thickness was 5.5 mm at 45 degrees in all cases but one, who had a liner thickness of 4.7mm, and all patients had a cobalt-chrome head. Cup sizes were 52mm (n=15, 68%) and 50mm (n=7, 32%). Mean linear liner wear was 0.0470 mm/year (range 0 - 0.2628 mm) and mean volumetric wear was 127.69 mm3/year (range 0 - 721.23 mm3/year).

Using HXLPE liners with 36-mm heads or bigger in 52-mm cups or smaller is safe, with low rates of linear and volumetric wear in the mid to long-term follow-up. Patients did not require revision surgery for liner complications, including liner fracture, dissociation, or wear. Our results suggest that the advantages of using larger heads should outweigh the potential risks of using thin HXLPE liners.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 34 - 34
1 Dec 2022
Sheridan G Garbuz D MacDonell T Neufeld M Howard L Beverland D Masri B
Full Access

The benefit of using acetabular screws in primary total hip arthroplasty (THA) has been questioned in recent years. The disadvantages of using screws include increased operative time, risk of injury to surrounding neurovascular structures and metal ware breakage. Recent large registry studies have reported that screws do not confer a protective effect against acetabular loosening or the presence of osteolysis. Other studies have even described an increased risk of aseptic acetabular loosening with the selective use of screws. We report findings from a multicentre cohort study.

This large cohort study compared clinical outcomes between primary acetabular components that were inserted with and without screws. Independent variables included the presence (or absence) of screws, the total number of screws used and the cumulative screw length (CSL). Outcome measures included all-cause revision, acetabular component revision and acetabular component loosening. Statistical software (Stata/IC 13.1 for Mac [64-bit Intel]) was used to conduct all statistical analyses. A p-value < 0 .05 taken to be significant.

There were 4,583 THAs performed in total. Screws were used in 15.9% (n=733). At a mean follow-up of 5.2 years, the all-cause revision rate in the screw cohort was 1.5% compared to 0.83% in the no screw cohort (p=0.085). There was no difference in acetabular component revision rates for screws (3/733, 0.41%) versus no screws (12/3,850, 0.31%) (p=0.439). The rate of acetabular loosening noted during the time of revision surgery was significantly higher when screws were used in the index procedure (2/733, 0.2%) compared to the no screw cohort (1/3,850, 0.02%) (p=0.017). There was no difference in outcomes when stratifying by the number of screws used or the cumulative screw length.

Primary acetabular components do not require screws for fixation. All cause revision rates and acetabular component revision rates are comparable for the screw and the no screw cohorts. The rate of acetabular component loosening, as observed during revision surgery, is significantly higher when screws are used in the index total hip replacement.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 19 - 19
1 Dec 2022
Gerges M Messner J Lim B Chhina H Cooper A
Full Access

Guided growth is commonly performed by placing an extra-periosteal two-hole plate across the growth plate with one epiphyseal and one metaphyseal screw. Recent work by Keshet et al. (2019) investigated the efficacy of the removal of the metaphyseal screw only (“sleeper plate”) after correction. They concluded the practice to be unnecessary as only 19% of patient show recurrence of deformity. The aim of this study is to examine the incidence of rebound and undesired bony in-growth of the plate (“tethering”) after metaphyseal screw removal only.

In this retrospective case series, patient data on 144 plates inserted around the knee was obtained. Plates still in situ (n=69) at time of study and full hardware removal (n=50) were excluded. The remaining 25 plates had a metaphyseal screw only removed after deformity correction. We analyzed the rate of re-bound, tethering and maintenance of correction in two age groups at latest follow-up for a mean of 3.5 years (1.25 to five). Fisher's exact test with Freeman-Halton extension was used to analyze the two by three contingency table.

Twenty-five plates were identified as “sleeper plates” in our series. 13 plates (52%) maintained the achieved correction after a mean of 21 months (four to 39), nine plates (36%) required screw re-insertion due to rebound after a mean of 22 months (12-48) from screw removal, and four plates (16%) showed tethering with undesired continuation of guided growth after a mean of 14 months (seven to 22) from screw removal. Younger patients (years at time of plate insertion) had higher rates of rebound and tethering (p=.0112, Fisher's exact test). All Tethering occurred in titanium plates, none occurred in steel plates.

The sleeper plate is an acceptable treatment strategy for coronal deformities around the knee. Rebounding and tethering are potential outcomes that occur in younger patients and should be disclosed to patients; titanium plates may increase the risk of tethering, however further long-term follow-up is needed. We stress the importance of close post-operative follow up to identify tethering early and prevent over correction.

The sleeper plate technique is a viable option in younger children with congenital abnormalities, however, continued monitoring of alignment is necessary after screw removal to check for rebound and tethering.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 5 - 5
1 Dec 2022
Li T Beaudry E Westover L Chan R
Full Access

The Adams-Berger reconstruction is an effective technique for treating distal radioulnar joint (DRUJ) instability. Graft preparation techniques vary amongst surgeons with insufficient evidence to support one technique over another. Our study evaluated the biomechanical properties of four graft preparation techniques.

Extensor tendons were harvested from fresh frozen porcine trotters obtained from a local butcher shop and prepared in one of three configurations (n=5 per group): tendon only; tendon prepared with non-locking, running suture (2-0 FiberLoop, Arthrex, Naples, FL) spaced at 6 mm intervals; and tendon prepared with suture spaced at 12 mm intervals. A fourth configuration of suture alone was also tested. Tendons were allocated in a manner to ensure comparable average diameters amongst groups. Biomechanical testing occurred using custom jigs simulating radial and ulnar tunnels attached to a Bose Electroforce 3510 mechanical testing machine (TA Instruments). After being woven through the jigs, all tendons were sutured end-to-end with 2-0 PROLENE suture (Ethicon). Tendons then underwent a staircase cyclic loading protocol (5-25 Newtons [N] at 1 hertz [Hz] for 1000 cycles, then 5-50 N at 1 Hz for 1000 cycles, then 5-75 N at 1 Hz for 1000 cycles) until graft failure; if samples did not fail during the protocol, they were then loaded to failure. Samples were visually inspected for mode of failure after the protocol. A one-way analysis of variance was used to compare average tendon diameter; post-hac Tuhey tests were used to compare elongation and elongation rate. Survival to cyclic loading was analyzed using Kaplan-Meier survival curves with log rank. Statistical significance was set at a = 0.05.

The average tendon diameter of each group was not statistically different [4.17 mm (tendon only), 4.33 mm (FiberLoop spaced 6 mm), and 4.30 mm (FiberLoop spaced 12 mm)]. The average survival of tendon augmented with FiberLoop was significantly higher than tendon only, and all groups had significantly improved survival compared to suture only. There was no difference in survival between FiberLoop spaced 6 mm and 12 mm. Elongation was significantly lower with suture compared to tendon augmented with FiberLoop spaced 6 mm. Elongation rate was significantly lower with suture compared to all groups. Modes of failure included rupture of the tendon, suture, or both at the simulated bone and suture and/or tendon interface, and elongation of the entire construct without rupture.

In this biomechanical study, augmentation of porcine tendons with FiberLoop suture spaced at either 6 or 12 mm for DRUJ reconstruction significantly increased survival to a staircase cyclic loading protocol, as suture material was significantly stiffer than any of the tendon graft configurations.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 105 - 105
1 Dec 2022
Hildebrand KM Hildebrand K Marritt K Arcila CS Singla A Monument M
Full Access

Undifferentiated pleomorphic sarcoma (UPS) is one of the most common and aggressive adult soft tissue sarcomas (STS). Once metastatic, UPS is rapidly fatal. Most STS, including UPS, are resistant to conventional immunotherapies as these tumours have low numbers of spontaneous tumour infiltrating lymphocytes (TILs) and are densely populated with immune suppressive macrophages. Intra-tumoural activation of the STimulator of INterferon Genes (STING) pathway is a novel immunotherapeutic strategy to recruit anti-tumour TILs into the tumour microenvironment. In a murine model of UPS, we have demonstrated that intra-tumoural injection of a murine-specific STING agonist, DMXAA, results in profound immune mediated tumour clearance. Recently, molecules capable of activating both human and mouse STING pathways have been developed. In pursuit of clinically relevant therapeutic opportunities, the purpose of this study is to evaluate the anti-tumour potential of two agonists of the human and murine STING receptors: ADU-S100 and MSA-2 as monotherapies and in combination with the immune checkpoint inhibitor, anti-PD1 in a murine model of UPS.

Immune competent mice were engrafted with murine UPS cells in the hindlimb muscle. Once palpable, mice in the monotherapy group were treated with a single intra-tumoural dose of 1) ADU-S100 or 2) MSA-2 or 3) DMXAA. In additional experimental groups, mice were treated with the different STING agonists and monoclonal anti-PD1. Tumour volume measurements and tumour bioluminescence were measured over time. To quantify dynamic changes in immune populations and in the tumour immune microenvironment, STING treated UPS tumours were evaluated using flow cytometry and mRNA quantification at various timepoints after therapy.

DMXAA monotherapy produced complete tumour eradication in 50% of mice, whereas both ADU-S100 or MSA-2 monotherapy only extended survival but did not result in complete tumour clearance. Flow cytometry and transcriptional profiling of tumours at multiple timepoints post-treatment showed similar inflammatory changes and increased TILs numbers across all STING agonists. The addition of anti-PD1 treatment to STING therapy significantly extended survival times with both ADU-S100 and MSA-2, and resulted in 14% complete tumour clearance with ADU-S100. No complete survivors were observed with MSA-2-anti-PD1 combinations therapy.

STING activation is a promising immunotherapeutic strategy for UPS. Recently developed human STING agonists are not as effective as DMXAA despite similar immunologic responses to treatment. STING and anti-PD-1 treatment were therapeutically synergistic for both human STING agonists. These results justify further research around STING activation as a therapeutic modality for STS. DMXAA may possess additional off-target therapeutic properties beyond STING activation which warrants further investigation. Elucidating these differences may be critical to further optimize STING therapy for human STS.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 106 - 106
1 Dec 2022
You D Korley R Duffy P Martin R Dodd A Buckley R Soo A Schneider P
Full Access

Prolonged bedrest in hospitalized patients is a major risk factor for venous thromboembolism (VTE), especially in high risk patients with hip fracture. Thrombelastography (TEG) is a whole blood viscoelastic hemostatic assay with evidence that an elevated maximal amplitude (MA), a measure of clot strength, is predictive of VTE in orthopaedic trauma patients. The objective of this study was to compare the TEG MA parameter between patients with hip fracture who were more mobile post-operatively and discharged from hospital early to patients with hip fracture with reduced mobility and prolonged hospitalizations post-operatively.

In this prospective cohort study, TEG analysis was performed in patients with hip fracture every 24-hours from admission until post-operative day (POD) 5, then at 2- and 6-weeks post-operatively. Hypercoagulability was defined by MA > 65. Patients were divided into an early (within 5-day) and late (after 5-day) discharge group, inpatient at 2-weeks group, and discharge to MSK rehabilitation (MSK rehab), and long term care (LTC) groups. Two-sample t-test was used to analyze differences in MA between the early discharge and less mobile groups. All statistical tests were two-sided, and p-values < 0.05 were considered statistically significant.

In total, 121 patients with a median age of 81.0 were included. Patients in the early discharge group (n=15) were younger (median age 64.0) and more likely to ambulate without gait aids pre-injury (86.7%) compared to patients in the late discharge group (n=105), inpatients at 2-weeks (n=48), discharged to MSK rehab (n=30), and LTC (n=20). At two weeks post-operative, the early discharge group was significantly less hypercoagulable (MA=68.9, SD 3.0) compared to patients in the other four groups. At 6-weeks post-operative, the early discharge group was the only group to demonstrate a trend towards mean MA below the MA > 65 hypercoagulable threshold (MA=64.4, p=0.45). Symptomatic VTE events were detected in three patients (2.5%) post-operatively. All three patients had hospitalizations longer than five days after surgery.

In conclusion, our analysis of hypercoagulability secondary to reduced post-operative mobility demonstrates that patients with hip fracture who were able to mobilize independently sooner after hip fracture surgery, have a reduced peak hypercoagulable state. In addition, there is a trend towards earlier return to normal coagulation status as determined by the TEG MA parameter. Post-operative mobility status may play a role in determining individualized duration of thromboprophylaxis following hip fracture surgery. Future studies comparing TEG to clinically validated mobility tools may more closely evaluate the contribution of venous stasis due to reduced mobility on hypercoagulation following hip fracture surgery.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 106 - 106
1 Dec 2022
Zwiebel X Pelet S Corriveau-Durand S
Full Access

Reported wound complication in below knee surgery can be quite high. Recent study demonstrated that increased blood loss and hematoma formation increase wound complications especially in foot and ankle surgeries. Despite the evidence on the benefit of TXA on blood loss in TKA and THA it is not routinely used by surgeon in below knee surgery.

To assess the efficacy and safety of this medication in reducing wound complication and blood loss and the risk of thromboembolic complications in patients undergoing below knee surgery. A systematic literature search of PubMed, Embase, Ovid, the Cochrane Library and AAOS and AOFAS conference proceedings was conducted. The primary outcome was the rate of wound complications. Data were analyzed using the Review Manager 5.3 software.

Nine studies involving 861 patients met the inclusion criteria. The meta-analysis indicated that TXA, when compared to a control group, reduced wound complications (OR, 0.54; 95% IC, 0.31 to 0.95, p = 0,03), blood loss (MD = −149,4 ml; 95% CI, −205,3ml to −93,6ml), post-operative drainage (MD = −169,8 ml; 95% CI, −176,7 to −162,9 ml) and hemoglobin drop (MD = −8,75 g/dL; 95% IC, −9,6 g/dL to −7,8 g/dL). There was no significant difference in thromboembolic events (RR 0,53; 95% CI, 0,15 - 1,90; p = 0,33).

This study demonstrated that TXA could be use in below knee surgery to reduce wound complication and blood loss without increased thromboembolic complications. The small number of studies limit the findings interpretation. Further studies are needed to sustain those resutls.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 51 - 51
1 Dec 2022
Gazendam A Bali K Tushinski D Petruccelli D Winemaker MJ de Beer J Wood T
Full Access

During total knee arthroplasty (TKA), a tourniquet is often used intraoperatively. There are proposed benefits of tourniquet use including shorter duration of surgery, improved surgical field visualization and increased cement penetration which may improve implant longevity. However, there are also cited side effects that include increased post-operative pain, slowed recovery, skin bruising, neurovascular injury and quadriceps weakness. Randomized controlled trials have demonstrated no differences in implant longevity, however they are limited by short follow-up and small sample sizes. The objective of the current study was to evaluate the rates of revision surgery among patients undergoing cemented TKA with or without an intraoperative tourniquet and to understand the causes and risk factors for failure.

A retrospective cohort study was undertaken of all patients who received a primary, cemented TKA at a high-volume arthroplasty centre from January 1999 to December 2010. Patients who underwent surgery without the use of a tourniquet and those who had a tourniquet inflated for the entirety of the case were included. The causes and timing of revision surgery were recorded and cross referenced with the Canadian Institute of Health Information Discharge Abstract Database to reduce the loss to follow-up. Survivorship analysis was performed with the use of Kaplan-Meier curves to determine overall survival rates at final follow-up. A Cox proportional hazards model was utilized to evaluate independent predictors of revision surgery.

Data from 3939 cases of primary cemented TKA were available for analysis. There were 2276 (58%) cases in which a tourniquet was used for the duration of the surgery and 1663 (42%) cases in which a tourniquet was not utilized. Mean time from the primary TKA was 14.7 years (range 0 days - 22.8 years) when censored by death or revision surgery. There were 150 recorded revisions in the entire cohort, with periprosthetic joint infection (n=50) and aseptic loosening (n=41) being the most common causes for revision. The cumulative survival at final follow-up for the tourniquetless group was 93.8% at final follow-up while the cumulative survival at final follow-up for the tourniquet group was 96.9% at final follow-up. Tourniquetless surgery was an independent predictor for all-cause revision with an HR of 1.53 (95% CI 1.1, 2.1, p=0.011). Younger age and male sex were also independent factors for all cause revision.

The results of the current study demonstrate higher all-cause revision rates with tourniquetless surgery in a large cohort of patients undergoing primary cemented TKA. The available literature consists of short-term trials and registry data, which have inherent limitations. Potential causes for increased revision rates in the tourniquetless group include reduced cement penetration, increased intraoperative blood loss and longer surgical. The results of the current study should be taken into consideration, alongside the known risks and benefits of tourniquet use, when considering intraoperative tourniquet use in cemented TKA.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 36 - 36
1 Dec 2022
Benavides B Cornell D Schneider P Hildebrand K
Full Access

Heterotopic ossification (HO) is a well-known complication of traumatic elbow injuries. The reported rates of post-traumatic HO formation vary from less than 5% with simple elbow dislocations, to greater than 50% in complex fracture-dislocations. Previous studies have identified fracture-dislocations, delayed surgical intervention, and terrible triad injuries as risk factors for HO formation. There is, however, a paucity of literature regarding the accuracy of diagnosing post-traumatic elbow HO. Therefore, the purpose of our study was to determine the inter-rater reliability of HO diagnosis using standard radiographs of the elbow at 52 weeks post-injury, as well as to report on the rate of mature compared with immature HO. We hypothesized inter-rater reliability would be poor among raters for HO formation.

Prospectively collected data from a large clinical trial was reviewed by three independent reviewers (one senior orthopedic resident, one senior radiology resident, and one expert upper extremity orthopedic surgeon). Each reviewer examined anonymized 52-week post-injury radiographs of the elbow and recorded: 1. the presence or absence of HO, 2. the location of HO, 3. the size of the HO (in cm, if present), and 4. the maturity of the HO formation. Maturity was defined by consensus prior to image review and defined as an area of well-defined cortical and medullary bone outside the cortical borders of the humerus, ulna, or radius. Immature lesions were defined as an area of punctate calcification with an ill-defined cloud-like density outside the cortical borders of the humerus, ulna or radius. Data were collected using a standardized online data collection form (CognizantMD, Toronto, ON, CA). Inter-rater reliability was calculated using Fleiss’ Kappa statistic and a multivariate logistic regression analysis was performed to identify risk factors for HO formation in general, as well as mature HO at 52 weeks post injury. Statistical analysis was performed using RStudio (version1.4, RStudio, Boston, MA, USA).

A total of 79 radiographs at the 52-week follow-up were reviewed (54% male, mean age 50, age SD 14, 52% operatively treated). Inter-rater reliability using Fleiss’ Kappa was k= 0.571 (p = 0.0004) indicating moderate inter-rater reliability among the three reviewers. The rate of immature HO at 52 weeks was 56%. The multivariate logistic regression analysis identified male sex as a significant risk factor for HO development (OR 5.29, 1.55-20.59 CI, p = 0.011), but not for HO maturity at 52 weeks. Age, time to surgery, and operative intervention were not found to be significant predictors for either HO formation or maturity of the lesion in this cohort.

Our study demonstrates moderate inter-rater reliability in determining the presence of HO at 52 weeks post-elbow injury. There was a high rate (56%) of immature HO at 52-week follow-up. We also report the finding of male sex as a significant risk factor for post traumatic HO development. Future research directions could include investigation into possible male predominance for traumatic HO formation, as well as improving inter-rater reliability through developing a standardized and validated classification system for reporting the radiographic features of HO formation around the elbow.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 54 - 54
1 Dec 2022
Stringer M Lethbridge L Richardson G Nagle M Boivin M Dunbar M
Full Access

The coronavirus pandemic has reduced the capability of Canadian hospitals to offer elective orthopaedic surgery requiring admission, despite ongoing and increasing demands for elective total hip and total knee arthroplasty surgery (THA and TKA). We sought to determine if the coronavirus pandemic resulted in more outpatient THA and TKA in Nova Scotia, and if so, what effect increased outpatient surgery had on 90 day post-operative readmission or Emergency Department/Family Doctor (FD) visits.

The study cohort was constructed from hospital Discharge Abstract Data (DAD), inpatient admissions, and National Ambulatory Care Reporting System (NACRS) data, day surgery observations, using Canadian Classification of Health Intervention codes to select all primary hip and knee procedures from 2005-2020 in Nova Scotia. Emergency Department and General Practitioner visits were identified from the Physician Billings data and re-admissions from the DAD and NACRS. Rates were calculated by dividing the number of cases with any visit within 90 days after discharge. Chi-squared statistics at 95% confidence level used to test for statistical significance. Knee and hip procedures were modelled separately.

There was a reduction in THA and TKA surgery in Nova Scotia during the coronavirus pandemic in 2020. Outpatient arthroplasty surgery in Nova Scotia in the years prior to 2020 were relatively stable. However, in 2020 there was a significant increase in the proportion and absolute number of outpatient THA and TKA. The proportion of THA increased from 1% in 2019 to 14% in 2020, while the proportion of TKA increased from 1% in 2019 to 11% in 2020. The absolute number of outpatient THA increased from 16 cases in 2019, to 163 cases in 2020. Outpatient TKA cases increased from 21 in 2019, to 173 in 2020. The increase in outpatient surgery resulted in an increase in 90 day presentations to ED following TKA but not THA which was not statistically significant. For outpatient THA and TKA, there was a decrease in 90 day readmissions, and a statistically significant decrease in FD presentations.

Outpatient THA and TKA increased significantly in 2020, likely due to the restrictions imposed during the coronavirus pandemic on elective Orthopaedic surgery requiring admission to hospital. The increase in outpatient surgery resulted in an increase in 90 day presentations to ED for TKA, and a decrease in 90 day readmissions and FD presentations for THA and TKA. Reducing the inpatient surgical burden may result in a post-operative burden on ED, but does not appear to have caused an increase in hospital readmission rates.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 56 - 56
1 Dec 2022
Tat J Hall J
Full Access

Open debridement and Outerbridge and Kashiwagi debridement arthroplasty (OK procedure) are common surgical treatments for elbow arthritis. However, the literature contains little information on the long-term survivorship of these procedures. The purpose of this study was to determine the survivorship after elbow debridement techniques until conversion to total elbow arthroplasty and revision surgery.

We performed a retrospective chart review of patients who underwent open elbow surgical debridement (open debridement, OK procedure) between 2000 and 2015. Patients were diagnosed with primary elbow osteoarthritis, post-traumatic arthritis, or inflammatory arthritis. A total of 320 patients had primary surgery including open debridement (n=142) and OK procedure (n=178), and of these 33 patients required a secondary revision surgery (open debridement, n=14 and OK procedure, n=19). The average follow-up time was 11.5 years (5.5 - 21.5 years). Survivorship was analyzed with Kaplan-Meier curves and Log Rank test. A Cox proportional hazards model was used assess the likelihood of conversion to total elbow arthroplasty or revision surgery while adjusting for covariates (age, gender, diagnosis). Significance was set p<0.05.

Kaplan-Meier survival curves showed open debridement was 100.00% at 1 year, 99.25% at 5 years, and 98.49% at 10 years and for OK procedure 100.00% at 1 year, 98.80% at 5 years, 97.97% at 10 years (p=0.87) for conversion to total elbow arthroplasty. There was no difference in survivorship between procedures after adjusting for significant covariates with the cox proportional hazard model. The rate of revision for open debridement and OK procedure was similar at 11.31% rand 11.48% after 10 years respectively. There were higher rates of revision surgery in patients with open debridement (hazard ratio, 4.84 CI 1.29 - 18.17, p = 0.019) compared to OK procedure after adjusting for covariates. We also performed a stratified analysis with radiographic severity as an effect modifier and showed grade 3 arthritis did better with the OK procedure compared to open debridement for survivorship until revision surgery (p=0.05). However, this difference was not found for grade 1 or grade 2 arthritis. This may suggest that performing the OK procedure for more severe grade 3 arthritis could decrease reoperation rates. Further investigations are needed to better understand the indications for each surgical technique.

This study is the largest cohort of open debridement and OK procedure with long term follow-up. We showed that open elbow debridement and the OK procedure have excellent survivorship until conversion to total elbow arthroplasty and are viable options in the treatment of primary elbow osteoarthritis and post traumatic cases. The OK procedure also has lower rates of revision surgery than open debridement, especially with more severe radiographic arthritis.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 40 - 40
1 Dec 2022
Dandurand C Mashayekhi M McIntosh G Street J Fisher C Jacobs B Johnson MG Paquet J Wilson J Hall H Bailey C Christie S Nataraj A Manson N Phan P Rampersaud RY Thomas K Dea N Soroceanu A Marion T Kelly A Santaguida C Finkelstein J Charest-Morin R
Full Access

Prolonged length of stay (LOS) is a significant contributor to the variation in surgical health care costs and resource utilization after elective spine surgery. The primary goal of this study was to identify patient, surgical and institutional variables that influence LOS. The secondary objective is to examine variability in institutional practices among participating centers.

This is a retrospective study of a prospectively multicentric followed cohort of patients enrolled in the CSORN between January 2015 and October 2020. A logistic regression model and bootstrapping method was used. A survey was sent to participating centers to assessed institutional level interventions in place to decrease LOS. Centers with LOS shorter than the median were compared to centers with LOS longer than the median.

A total of 3734 patients were included (979 discectomies, 1102 laminectomies, 1653 fusions). The median LOS for discectomy, laminectomy and fusion were respectively 0.0 day (IQR 1.0), 1.0 day (IQR 2.0) and 4.0 days (IQR 2.0). Laminectomy group had the largest variability (SD=4.4, Range 0-133 days). For discectomy, predictors of LOS longer than 0 days were having less leg pain, higher ODI, symptoms duration over 2 years, open procedure, and AE (p< 0.05). Predictors of longer LOS than median of 1 day for laminectomy were increasing age, living alone, higher ODI, open procedures, longer operative time, and AEs (p< 0.05). For posterior instrumented fusion, predictors of longer LOS than median of 4 days were older age, living alone, more comorbidities, less back pain, higher ODI, using narcotics, longer operative time, open procedures, and AEs (p< 0.05). Ten centers (53%) had either ERAS or a standardized protocol aimed at reducing LOS.

In this study stratifying individual patient and institutional level factors across Canada, several independent predictors were identified to enhance the understanding of LOS variability in common elective lumbar spine surgery. The current study provides an updated detailed analysis of the ongoing Canadian efforts in the implementation of multimodal ERAS care pathways. Future studies should explore multivariate analysis in institutional factors and the influence of preoperative patient education on LOS.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 43 - 43
1 Dec 2022
Pelletier-Roy R Dionne A Richard-Denis A Briand M Bourassa-Moreau E Mac-Thiong J
Full Access

Acute spinal cord injury (SCI) is most often secondary to trauma, and frequently presents with associated injuries. A neurological examination is routinely performed during trauma assessment, including through Advanced Trauma Life Support (ATLS). However, there is no standard neurological assessment tool specifically used for trauma patients to detect and characterize SCI during the initial evaluation. The International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) is the most comprehensive and popular tool for assessing SCI, but it is not adapted to the acute trauma patients such that it is not routinely used in that setting. Therefore, the objective is to develop a new tool that can be used routinely in the initial evaluation of trauma patients to detect and characterize acute SCI, while preserving basic principles of the ISNCSCI.

The completion rate of the ISCNSCI during the initial evaluation after an acute traumatic SCI was first estimated. Using a modified Delphi technique, we designed the Montreal Acute Classification of Spinal Cord Injuries (MAC-SCI), a new tool to detect and characterize the completeness (grade) and level of SCI in the polytrauma patient. The ability of the MAC-SCI to detect and characterize SCI was validated in a cohort of 35 individuals who have sustained an acute traumatic SCI. The completeness and neurological level of injury (NLI) were assessed by two independent assessors using the MAC-SCI, and compared to those obtained with the ISNCSCI.

Only 33% of patients admitted after an acute traumatic SCI had a complete ISNCSCI performed at initial presentation. The MAC-SCI includes 53 of the 134 original elements of the ISNCSCI which is 60% less. There was a 100% concordance between the severity grade derived from the MAC-SCI and from the ISNCSCI. Concordance of the NLI within two levels of that obtained from the ISNCSCI was observed in 100% of patients with the MAC-SCI and within one level in 91% of patients. The ability of the MAC-SCI to discriminate between cervical (C0 to C7) vs. thoracic (T1 to T9) vs. thoraco-lumbar (T10 to L2) vs. lumbosacral (L3 to S5) injuries was 100% with respect to the ISNCSCI.

The rate of completion of the ISNCSCI is low at initial presentation after an acute traumatic SCI. The MAC-SCI is a streamlined tool proposed to detect and characterize acute SCI in polytrauma patients, that is specifically adapted to the acute trauma setting. It is accurate for determining the completeness of the SCI and localize the NLI (cervical vs. thoracic vs. lumbar). It could be implemented in the initial trauma assessment protocol to guide the acute management of SCI patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 46 - 46
1 Dec 2022
de Vries G McDonald T Somayaji C
Full Access

Worldwide, most spine imaging is either “inappropriate” or “probably inappropriate”. The Choosing Wisely recommendation is “Do not perform imaging for lower back pain unless red flags are present.” There is currently no detailed breakdown of lower back pain diagnostic imaging performed in New Brunswick (NB) to inform future directions.

A registry of spine imaging performed in NB from 2011-2019 inclusive (n=410,000) was transferred to the secure platform of the NB Institute for Data, Training and Research (NB-IRDT). The pseudonymized data included linkable institute identifiers derived from an obfuscated Medicare number, as well as information on type of imaging, location of imaging, and date of imaging. The transferred data did not include the radiology report or the test requisition.

We included all lumbar, thoracic, and complete spine images. We excluded imaging related to the cervical spine, surgical or other procedures, out-of-province patients and imaging of patients under 19 years.

We verified categories of X-ray, Computed Tomography (CT), and Magnetic Resonance Imaging (MRI). Red flags were identified by ICD-10 code-related criteria set out by the Canadian Institute for Health Information.

We derived annual age- and sex-standardized rates of spine imaging per 100,000 population and examined regional variations in these rates in NB's two Regional Health Authorities (RHA-A and RHA-B). Age- and sex-standardized rates were derived for individuals with/without red flag conditions and by type of imaging. Healthcare utilization trends were reflected in hospital admissions and physician visits 2 years pre- and post-imaging. Rurality and socioeconomic status were derived using patients’ residences and income quintiles, respectively.

Overall spine imaging rates in NB decreased between 2012 and 2019 by about 20% to 7,885 images per 100,000 people per year. This value may be higher than the Canadian average.

Females had 23% higher average imaging rate than males. RHA-A had a 45% higher imaging rate than RHA-B. Imaging for red flag conditions accounted for about 20% of all imaging.

X-rays imaging accounted for 67% and 75% of all imaging for RHA-A and RHA-B respectively. The proportions were 20% and 8% for CT and 13% and 17% for MRI.

Two-year hospitalization rates and rates of physician visits were higher post-imaging. Females had higher age-standardized hospitalization and physician-visit rates, but the magnitude of increase was higher for males. Individuals with red flag conditions were associated with increased physician visits, regardless of the actual reason for the visit.

Imaging rates were higher for rural than urban patients by about 26%. Individuals in the lowest income quintiles had higher imaging rates than those in the highest income quintiles. Physicians in RHA-A consistently ordered more images than their counterparts at RHA-B.

We linked spine imaging data with population demographic data to look for variations in lumbar spine imaging patterns. In NB, as in other jurisdictions, imaging tests of the spine are occurring in large numbers. We determined that patterns of imaging far exceed the numbers expected for ‘red flag’ situations. Our findings will inform a focused approach in groups of interest. Implementing high value care recommendations pre-imaging ought to replace low-value routine imaging.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 10 - 10
1 Dec 2022
Behman A Bradley C Maddock C Sharma S Kelley S
Full Access

There is no consensus regarding the optimum frequency of ultrasound for monitoring the response to Pavlik harness (PH) treatment in developmental dysplasia of hip (DDH). The purpose of our study was to determine if a limited-frequency hip ultrasound (USS) assessment in children undergoing PH treatment for DDH had an adverse effect on treatment outcomes when compared to traditional comprehensive ultrasound monitoring.

This study was a single-center non-inferiority randomized controlled trial. Children aged less than six months of age with dislocated, dislocatable and stable dysplastic hips undergoing a standardized treatment program with a PH were randomized, once stability had been achieved, to our current standard USS monitoring protocol (every clinic visit) or to a limited-frequency ultrasound protocol (USS only until hip stability and then end of treatment). Groups were compared based on alpha angle at the end of treatment, acetabular indices (AI) and IHDI grade on follow up radiographs at one-year post harness and complication rates. The premise was that if there were no differences in these outcomes, either protocol could be deemed safe and effective.

One hundred patients were recruited to the study; after exclusions, 42 patients completed the standard protocol (SP) and 36 completed the limited protocol (LP). There was no significant difference between the mean age between both groups at follow up x-ray (SP: 17.8 months; LP: 16.6 months; p=0.26). There was no difference between the groups in mean alpha angle at the end of treatment (SP: 69°; LP: 68.1°: p=0.25). There was no significant difference in the mean right AI at follow up (SP: 23.1°; LP: 22.0°; p=0.26), nor on the left (SP:23.3°; LP 22.8°; p=0.59). All hips in both groups were IHDI grade 1 at follow up. The only complication was one femoral nerve palsy in the SP group. In addition, the LP group underwent a 60% reduction in USS use once stable.

We found that once dysplastic or dislocated hips were reduced and stable on USS, a limited- frequency ultrasound protocol was not associated with an inferior complication or radiographic outcome profile compared to a standardized PH treatment pathway. Our study supports reducing the frequency of ultrasound assessment during PH treatment of hip dysplasia. Minimizing the need for expensive, time-consuming and in-person health care interventions is critical to reducing health care costs, improving patient experience and assists the move to remote care. Removing the need for USS assessment at every PH check will expand care to centers where USS is not routinely available and will facilitate the establishment of virtual care clinics where clinical examination may be performed remotely.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 29 - 29
1 Dec 2022
Tyrpenou E Lee D Robbins S Ippersiel P Antoniou J
Full Access

Hip instability is one of the most common causes for total hip arthroplasty (THA) revision surgery. Studies have indicated that lumbar fusion (LF) surgery is a risk factor for hip dislocation. Instrumented spine fusion surgery decreases pelvic tilt, which might lead to an increase in hip motion to accommodate this postural change. To the best of our knowledge, spine-pelvis-hip kinematics during a dynamic activity in patients that previously had both a THA and LF have not been investigated. Furthermore, patients with a combined THA and LF tend to have greater disability. The purpose was to examine spine-pelvis-hip kinematics during a sit to stand task in patients that have had both THA and LF surgeries and compare it to a group of patients that had a THA with no history of spine surgery. The secondary purpose was to compare pain, physical function, and disability between these patients.

This cross-sectional study recruited participants that had a combined THA and LF (n=10; 6 females, mean age 73 y) or had a THA only (n=11; 6 females, mean age 72 y). Spine, pelvis, and hip angles were measured using a TrakSTAR motion capture system sampled at 200 Hz. Sensors were mounted over the lateral thighs, base of the sacrum, and the spinous process of the third lumbar,12th thoracic, and ninth thoracic vertebrae. Participants completed 10 trials of a standardized sit-to-stand-to-sit task. Hip, pelvis, lower lumbar, upper lumbar, and lower thoracic sagittal joint angle range of motion (ROM) were calculated over the entire task. In addition, pain, physical function, and disability were measured with clinical outcomes: Hip Disability Osteoarthritis Outcome Score (pain and physical function), Oswestry Low Back Disability Questionnaire (disability), and Harris Hip Score (pain, physical function, motion). Physical function performance was measured using 6-Minute Walk Test, Stair Climb Test, and 30s Chair Test. Angle ROMs during the sit-to-stand-to-sit task and clinical outcomes were compared between THA+LF and THA groups using independent t-tests and effect sizes (d).

The difference in hip ROM was approaching statistical significance (p=0.07). Specifically, the THA+LF group had less hip ROM during the sit-to-stand-to-sit task than the THA only group (mean difference=11.17, 95% confidence interval=-1.13 to 23.47), which represented a large effect size (d=0.83). There were no differences in ROM for pelvis (p=0.54, d=0.28) or spinal (p=0.14 to 0.97; d=0.02 to 0.65) angles between groups. The THA+LF group had worse clinical outcomes for all measures of pain, physical function, and disability (p=0.01 to 0.06), representing large effect sizes (d=0.89 to 2.70).

Hip ROM was not greater in the THA+LF group, and thus this is unlikely a risk factor for hip dislocation during this specific sit-to-stand-to-sit task. Other functional tasks that demand greater excursions in the joints should be investigated. Furthermore, the lack of differences in spinal and pelvis ROM were likely due to the task and the THA+LF group had spinal fusions at different levels. Combined THA+LF results in worse clinical outcomes and additional rehabilitation is required for these patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 12 - 12
1 Dec 2022
Li W Stimec J Camp M Pusic M Herman J Boutis K
Full Access

Diagnostic interpretation error of paediatric musculoskeletal (MSK) radiographs can lead to late presentation of injuries that subsequently require more invasive surgical interventions with increased risks of morbidity. We aimed to determine the radiograph factors that resulted in diagnostic interpretation challenges for emergency physicians reviewing pediatric MSK radiographs.

Emergency physicians provided diagnostic interpretations on 1,850 pediatric MSK radiographs via their participation in a web-based education platform. From this data, we derived interpretation difficulty scores for each radiograph using item response theory. We classified each radiograph by body region, diagnosis (fracture/dislocation absent or present), and, where applicable, the specific fracture location(s) and morphology(ies). We compared the interpretation difficulty scores by diagnosis, fracture location, and morphology. An expert panel reviewed the 65 most commonly misdiagnosed radiographs without a fracture/dislocation to identify normal imaging findings that were commonly mistaken for fractures.

We included data from 244 emergency physicians, which resulted in 185,653 unique radiograph interpretations, 42,689 (23.0%) of which were diagnostic errors. For humerus, elbow, forearm, wrist, femur, knee, tibia-fibula radiographs, those without a fracture had higher interpretation difficulty scores relative to those with a fracture; the opposite was true for the hand, pelvis, foot, and ankle radiographs (p < 0 .004 for all comparisons). The descriptive review demonstrated that specific normal anatomy, overlapping bones, and external artefact from muscle or skin folds were often mistaken for fractures. There was a significant difference in difficulty score by anatomic locations of the fracture in the elbow, pelvis, and ankle (p < 0 .004 for all comparisons). Ankle and elbow growth plate, fibular avulsion, and humerus condylar were more difficult to diagnose than other fracture patterns (p < 0 .004 for all comparisons).

We identified actionable learning opportunities in paediatric MSK radiograph interpretation for emergency physicians. We will use this information to design targeted education to referring emergency physicians and their trainees with an aim to decrease delayed and missed paediatric MSK injuries.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 30 - 30
1 Dec 2022
McGoldrick N Cochran M Biniam B Bhullar R Beaulé P Kim P Gofton W Grammatopoulos G
Full Access

Short cementless femoral stems are increasingly popular as they allow for less dissection for insertion. Use of such stems with the anterior approach (AA) may be associated with considerable per-operative fracture risk. This study's primary aim was to evaluate whether patient-specific femoral- and pelvic- morphology and surgical technique, influence per-operative fracture risk. In doing so, we aimed to describe important anatomical thresholds alerting surgeons.

This is a single-center, multi-surgeon retrospective, case-control matched study. Of 1145 primary THAs with a short, cementless stem inserted via the AA, 39 periprosthetic fractures (3.4%) were identified. These were matched for factors known to increase fracture risk (age, gender, BMI, side, Dorr classification, stem offset and indication for surgery) with 78 THAs that did not sustain a fracture. Radiographic analysis was performed using validated software to measure femoral- (canal flare index [CFI], morphological cortical index [MCI], calcar-calcar ratio [CCR]) and pelvic- (Ilium-ischial ratio [IIR], ilium overhang, and ASIS to greater trochanter distance) morphologies and surgical technique (% canal fill). Multivariate and Receiver-Operator Curve (ROC) analysis was performed to identify predictors of fracture.

Femoral factors that differed included CFI (3.7±0.6 vs 2.9±0.4, p3.17 and II ratio>3 (OR:29.2 95%CI: 9.5–89.9, p<0.001).

Patient-specific anatomical parameters are important predictors of fracture-risk. When considering the use of short stems via the AA, careful radiographic analysis would help identify those at risk in order to consider alternative stem options.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 15 - 15
1 Dec 2022
Lemieux V Schwartz N Bouchard M Howard AW
Full Access

Timely and competent treatment of paediatric fractures is paramount to a healthy future working population. Anecdotal evidence suggests that children travel greater distances to obtain care compared to adults causing economic and geographic inequities. This study aims to qualify the informal regionalization of children's fracture care in Ontario. The results could inform future policy on resource distribution and planning of the provincial health care system.

A retrospective cohort study was conducted examining two of the most common paediatric orthopaedic traumatic injuries, femoral shaft and supracondylar humerus fractures (SCH), in parallel over the last 10 years (2010-2020) using multiple linked administrative databases housed at the Institute for Clinical Evaluative Sciences (ICES) in Toronto, Ontario. We compared the distance travelled by these pediatric cohorts to clinically equivalent adult fracture patterns (distal radius fracture (DR) and femoral shaft fracture). Patient cohorts were identified based on treatment codes and distances were calculated from a centroid of patient home forward sortation area to hospital location. Demographics, hospital type, and closest hospital to patient were also recorded.

For common upper extremity fracture care, 84% of children underwent surgery at specialized centers which required significant travel (44km). Conversely, 67% of adults were treated locally, travelling a mean of 23km. Similarly, two-thirds of adult femoral shaft fractures were treated locally (mean travel distance of 30km) while most children (84%) with femoral shaft fractures travelled an average of 63km to specialized centers. Children who live in rural areas travel on average 51km more than their adult rural-residing counterparts for all fracture care. Four institutions provide over 75% of the fracture care for children, whereas 22 institutions distribute the same case volume in adults.?

Adult fracture care naturally self-organizes with proportionate distribution without policy-directed systemization. There is an unplanned concentration of pediatric fracture care to specialized centers in Ontario placing undue burden on pediatric patients and inadvertently stresses the surgical resources in a small handful of hospitals. In contrast, adult fracture care naturally self-organizes with proportionate distribution without policy-directed systemization. Patient care equity and appropriate resource allocation cannot be achieved without appropriate systemization of pediatric fracture care.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 33 - 33
1 Dec 2022
Abbas A Lex J Toor J Mosseri J Khalil E Ravi B Whyne C
Full Access

Total knee and hip arthroplasty (TKA and THA) are two of the highest volume and resource intensive surgical procedures. Key drivers of the cost of surgical care are duration of surgery (DOS) and postoperative inpatient length of stay (LOS). The ability to predict TKA and THA DOS and LOS has substantial implications for hospital finances, scheduling and resource allocation. The goal of this study was to predict DOS and LOS for elective unilateral TKAs and THAs using machine learning models (MLMs) constructed on preoperative patient factors using a large North American database.

The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for elective unilateral TKA and THA procedures from 2014-2019. The dataset was split into training, validation and testing based on year. Multiple conventional and deep MLMs such as linear, tree-based and multilayer perceptrons (MLPs) were constructed. The models with best performance on the validation set were evaluated on the testing set. Models were evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer of the actual target), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure useful predictions, the results of the models were compared to a mean regressor.

A total of 499,432 patients (TKA 302,490; THA 196,942) were included. The MLP models had the best MSEs and accuracy across both TKA and THA patients. During testing, the TKA MSEs for DOS and LOS were 0.893 and 0.688 while the THA MSEs for DOS and LOS were 0.895 and 0.691. The TKA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 78.8% and 88.3%, while the TKA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 75.2% and 76.1%. The THA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 81.6% and 91.4%, while the THA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 78.3% and 80.4%. All models across both TKA and THA patients were more accurate than the mean regressors for both DOS and LOS predictions across both buffer and classification accuracies.

Conventional and deep MLMs have been effectively implemented to predict the DOS and LOS of elective unilateral TKA and THA patients based on preoperative patient factors using a large North American database with a high level of accuracy. Future work should include using operational factors to further refine these models and improve predictive accuracy. Results of this work will allow institutions to optimize their resource allocation, reduce costs and improve surgical scheduling.

Acknowledgements:

The American College of Surgeons National Surgical Quality Improvement Program and the hospitals participating in the ACS NSQIP are the source of the data used herein; they have not verified and are not responsible for the statistical validity of the data analysis or the conclusions derived by the authors.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 16 - 16
1 Dec 2022
Hornestam JF Abraham A Girard C Del Bel M Romanchuk N Carsen S Benoit D
Full Access

Background: Anterior cruciate ligament (ACL) injury and re-injury rates are high and continue to rise in adolescents. After surgical reconstruction, less than 50% of patients return to their pre-injury level of physical activity. Clearance for return-to-play and rehabilitation progression typically requires assessment of performance during functional tests. Pain may impact this performance. However, the patient's level of pain is often overlooked during these assessments.

Purpose: To investigate the level of pain during functional tests in adolescents with ACL injury.

Fifty-nine adolescents with ACL injury (ACLi; female n=43; 15 ± 1 yrs; 167.6 ± 8.4 cm; 67.8 ± 19.9 kg) and sixty-nine uninjured (CON; female n=38; 14 ± 2 yrs; 165.0 ± 10.8 cm; 54.2 ± 11.5 kg) performed a series of functional tests. These tests included: maximum voluntary isometric contraction (MVIC) and isokinetic knee flexion-extension strength tests, single-limb hop tests, double-limb squats, countermovement jumps (CMJ), lunges, drop-vertical jumps (DVJ), and side-cuts. Pain was reported on a 5-point Likert scale, with 1 indicating no pain and 5 indicating extreme pain for the injured limb of the ACLi group and non-dominant limb for the CON group, after completion of each test. Chi-Square test was used to compare groups for the level of pain in each test. Analysis of the level of pain within and between groups was performed using descriptive statistics.

The distribution of the level of pain was different between groups for all functional tests (p≤0.008), except for ankle plantar flexion and hip abduction MVICs (Table 1). The percentage of participants reporting pain was higher in the ACLi group in all tests compared to the CON group (Figure 1). Participants most often reported pain during the strength tests involving the knee joint, followed by the hop tests and dynamic tasks, respectively. More specifically, the knee extension MVIC was the test most frequently reported as painful (70% of the ACLi group), followed by the isokinetic knee flexion-extension test, with 65% of ACLi group. In addition, among all hop tests, pain was most often reported during the timed 6m hop (53% of ACLi), and, among all dynamic tasks, during the side-cut (40% of ACLi) test (Figure 1). Furthermore, the tests that led to the higher levels of pain (severe or extreme) were the cross-hop (9.8% of ACLi), CMJ (7.1% of ACLi), and the isokinetic knee flexion-extension test (11.5% of ACLi) (Table 1).

Adolescents with and without ACL injury reported different levels of pain for all functional tasks, except for ankle and hip MVICs. The isokinetic knee flexion-extension test resulted in greater rates of severe or extreme pain and was also the test most frequently reported as painful. Functional tests that frequently cause pain or severe level of pain (e.g., timed 6m and cross hops, side-cut, knee flexion/extension MVICs and isokinetic tests) might not be the first test choices to assess function in patients after ACL injury/reconstruction. Reported pain during functional tests should be considered by clinicians and rehabilitation team members when evaluating a patient's readiness to return-to-play.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 109 - 109
1 Dec 2022
Clarke A Korley R Dodd A Duffy P Martin R Skeith L Schneider P
Full Access

Major orthopaedic fractures are an independent risk factor for the development of venous thromboembolism (VTE), which are significant causes of preventable morbidity and mortality in trauma patients. Despite thromboprophylaxis, patients who sustain a pelvic or acetabular fracture (PA) continue to have high rates of VTE (12% incidence). Thrombelastography (TEG) is a whole-blood, point-of-care test which provides an overview of the clotting process. Maximal amplitude (MA), from TEG analysis, is the measure of clot strength and values ≥65mm have been used to quantify hypercoagulability and increased VTE risk. Therefore, the primary aim was to use serial TEG analysis to quantify the duration of hypercoagulability, following surgically treated PA fractures.

This is a single centre, prospective cohort study of adult patients 18 years or older with surgically treated PA fractures. Consecutive patients were enrolled from a Level I trauma centre and blood draws were taken over a 3-month follow-up period for serial TEG analysis. Hypercoagulability was defined as MA ≥65mm. Exclusion criteria: bleeding disorders, active malignancy, current therapeutic anticoagulation, burns (>20% of body surface) and currently, or expecting to become pregnant within study timeframe.

Serial TEG analysis was performed using a TEG6s hemostasis analyzer (Haemonetics Corp.) upon admission, pre-operatively, on post-operative day (POD) 1, 3, 5, 7 (or until discharged from hospital, whichever comes sooner), then in follow-up at 2-, 4-, 6-weeks and 3-months post-operatively. Patients received standardized thromboprophylaxis with low molecular weight heparin for 28 days post-operatively. VTE was defined as symptomatic DVT or PE, or asymptomatic proximal DVT, and all participants underwent a screening post-operative lower extremity Doppler ultrasound on POD3. Descriptive statistics were used to determine the association between VTE events and MA values. For the primary outcome measure, the difference between the MA threshold value (≥65mm) and serial MA measures, were compared using one-sided t-tests (α=0.05).

Twenty-eight patients (eight females, 29%) with a mean age of 48±18 years were included. Acetabular fractures were sustained by 13 patients (46%), pelvic fractures by 14 patients (50%), and one patient sustained both. On POD1, seven patients (25%) were hypercoagulable, with 21 patients (78%) being hypercoagulable by POD3, and 17 patients (85%) by POD5. The highest average MA values (71.7±3.9mm) occurred on POD7, where eight patients (89%) were hypercoagulable. At 2-weeks post-operatively, 16 patients (94%) were hypercoagulable, and at four weeks, when thromboprophylaxis was discontinued, six patients (40%) remained hypercoagulable. Hypercoagulability persisted for five patients (25%) at 6-weeks and for two patients (10%) by three months.

There were six objectively diagnosed VTE events (21.4%), five were symptomatic, with a mean MA value of 69.3mm±4.3mm at the time of diagnosis. Of the VTE events, four occurred in participants with acetabular fractures (three male, 75%) and two in those with pelvic fractures (both males).

At 4-weeks post-operatively, when thromboprophylaxis is discontinued, 40% of patients remained hypercoagulable and likely at increased risk for VTE. At 3-months post-operatively, 10% of the cohort continued to be hypercoagulable. Serial TEG analysis warrants further study to help predict VTE risk and to inform clinical recommendations following PA fractures.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 39 - 39
1 Dec 2022
Grammatopoulos G Pierrepont J Madurawe C Innmann MM Vigdorchik J Shimmin A
Full Access

A stiff spine leads to increased demand on the hip, creating an increased risk of total hip arthroplasty (THA) dislocation. Several authors propose that a change in sacral slope of ≤10° between the standing and relaxed-seated positions (ΔSSstanding→relaxed-seated) identifies a patient with a stiff lumbar spine and have suggested use of dual-mobility bearings for such patients. However, such assessment may not adequately test the lumbar spine to draw such conclusions. The aim of this study was to assess how accurately ΔSSstanding→relaxed-seated can identify patients with a stiff spine.

This is a prospective, multi-centre, consecutive cohort series. Two-hundred and twenty-four patients, pre-THA, had standing, relaxed-seated and flexed-seated lateral radiographs. Sacral slope and lumbar lordosis were measured on each functional X-ray. ΔSSstanding→relaxed-seated seated was determined by the change in sacral slope between the standing and relaxed-seated positions. Lumbar flexion (LF) was defined as the difference in lumbar lordotic angle between standing and flexed-seated. LF≤20° was considered a stiff spine. The predictive value of ΔSSstanding→relaxed-seated for characterising a stiff spine was assessed.

A weak correlation between ΔSSstanding→relaxed-seated and LF was identified (r2= 0.15). Fifty-four patients (24%) had ΔSSstanding→relaxed-seated ≤10° and 16 patients (7%) had a stiff spine. Of the 54 patients with ΔSSstanding→relaxed-seated ≤10°, 9 had a stiff spine. The positive predictive value of ΔSSstanding→relaxed-seated ≤10° for identifying a stiff spine was 17%.

ΔSSstanding→relaxed-seated ≤10° was not correlated with a stiff spine in this cohort. Utilising this simplified approach could lead to a six-fold overprediction of patients with a stiff lumbar spine. This, in turn, could lead to an overprediction of patients with abnormal spinopelvic mobility, unnecessary use of dual mobility bearings and incorrect targets for component alignment. Referring to patients ΔSSstanding→relaxed-seated ≤10° as being stiff can be misleading; we thus recommend use of the flexed-seated position to effectively assess pre-operative spinopelvic mobility.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 20 - 20
1 Dec 2022
Ng G El Daou H Bankes M Cobb J Beaulé P
Full Access

Femoroacetabular impingement (FAI) – enlarged, aspherical femoral head deformity (cam-type) or retroversion/overcoverage of the acetabulum (pincer-type) – is a leading cause for early hip osteoarthritis. Although anteverting/reverse periacetabular osteotomy (PAO) to address FAI aims to preserve the native hip and restore joint function, it is still unclear how it affects joint mobility and stability. This in vitro cadaveric study examined the effects of surgical anteverting PAO on range of motion and capsular mechanics in hips with acetabular retroversion.

Twelve cadaveric hips (n = 12, m:f = 9:3; age = 41 ± 9 years; BMI = 23 ± 4 kg/m2) were included in this study. Each hip was CT imaged and indicated acetabular retroversion (i.e., crossover sign, posterior wall sign, ischial wall sign, retroversion index > 20%, axial plane acetabular version < 15°); and showed no other abnormalities on CT data. Each hip was denuded to the bone-and-capsule and mounted onto a 6-DOF robot tester (TX90, Stäubli), equipped with a universal force-torque sensor (Omega85, ATI). The robot positioned each hip in five sagittal angles: Extension, Neutral 0°, Flexion 30°, Flexion 60°, Flexion 90°; and performed hip internal-external rotations and abduction-adduction motions to 5 Nm in each position. After the intact stage was tested, each hip underwent an anteverting PAO, anteverting the acetabulum and securing the fragment with long bone screws. The capsular ligaments were preserved during the surgery and each hip was retested postoperatively in the robot. Postoperative CT imaging confirmed that the acetabular fragment was properly positioned with adequate version and head coverage. Paired sample t-tests compared the differences in range of motion before and after PAO (CI = 95%; SPSS v.24, IBM).

Preoperatively, the intact hips with acetabular retroversion demonstrated constrained internal-external rotations and abduction-adduction motions. The PAO reoriented the acetabular fragment and medialized the hip joint centre, which tightened the iliofemoral ligament and slackenend the pubofemoral ligament. Postoperatively, internal rotation increased in the deep hip flexion positions of Flexion 60° (∆IR = +7°, p = 0.001) and Flexion 90° (∆IR = +8°, p = 0.001); while also demonstrating marginal decreases in external rotation in all positions. In addition, adduction increased in the deep flexion positions of Flexion 60° (∆ADD = +11°, p = 0.002) and Flexion 90° (∆ADD = +12°, p = 0.001); but also showed marginal increases in abduction in all positions.

The anteverting PAO restored anterosuperior acetabular clearance and increased internal rotation (28–33%) and adduction motions (29–31%) in deep hip flexion. Restricted movements and positive impingement tests typically experienced in these positions with acetabular retroversion are associated with clinical symptoms of FAI (i.e., FADIR). However, PAO altered capsular tensions by further tightening the anterolateral hip capsule which resulted in a limited external rotation and a stiffer and tighter hip. Capsular tightness may still be secondary to acetabular retroversion, thus capsular management may be warranted for larger corrections or rotational osteotomies. In efforts to optimize surgical management and clinical outcomes, anteverting PAO is a viable option to address FAI due to acetabular retroversion or overcoverage.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 26 - 26
1 Dec 2022
Lapner P Pollock J Hodgdon T Zhang T McIlquham K Coupal S Bouliane M McRae S Dubberley J Berdusco R Stranges G Marsh J Old J MacDonald PB
Full Access

Our primary objective was to compare healing rates in patients undergoing arthroscopic rotator cuff repair for degenerative tears, with and without bone channeling. Our secondary objectives were to compare disease-specific quality of life and patient reported outcomes as measured by the Western Ontario Rotator Cuff Index (WORC), American Shoulder and Elbow Surgeons (ASES) score and Constant score between groups.

Patients undergoing arthroscopic rotator cuff repair at three sites were randomized to receive either bone channeling augmentation or standard repair. Healing rates were determined by ultrasound at 6 and 24 months post operatively. WORC, ASES, and Constant scores were compared between groups at baseline and at 3, 6, 12 and 24 months post operatively.

One hundred sixty-eight patients were recruited and randomized between 2013 to 2018. Statistically significant improvements occurred in both groups from pre-operative to all time points in all clinical outcome scores (p < 0 .0001). Intention to treat analysis revealed no statistical differences in healing rates between the two interventions at 24 months post-operative. No differences were observed in WORC, ASES or Constant scores at any time-point.

This trial did not demonstrate superiority of intra-operative bone channeling in rotator cuff repair surgery at 24 months post-operative. Healing rates and patient-reported function and quality of life measures were similar between groups.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 29 - 29
1 Dec 2022
Alolabi B Shanthanna H Czuczman M Moisiuk P O'Hare T Khan M Forero M Davis K Moro JK Foster G Thabane L
Full Access

Interscalene brachial plexus block is the standard regional analgesic technique for shoulder surgery. Given its adverse effects, alternative techniques have been explored. Reports suggest that the erector spinae plane block may potentially provide effective analgesia following shoulder surgery. However, its analgesic efficacy for shoulder surgery compared with placebo or local anaesthetic infiltration has never been established.

We conducted a randomised controlled trial to compare the analgesic efficacy of pre-operative T2 erector spinae plane block with peri-articular infiltration at the end of surgery. Sixty-two patients undergoing arthroscopic shoulder repair were randomly assigned to receive active erector spinae plane block with saline peri-articular injection (n = 31) or active peri-articular injection with saline erector spinae plane block (n = 31) in a blinded double-dummy design. Primary outcome was resting pain score in recovery. Secondary outcomes included pain scores with movement; opioid use; patient satisfaction; adverse effects in hospital; and outcomes at 24 h and 1 month.

There was no difference in pain scores in recovery, with a median difference (95%CI) of 0.6 (-1.9-3.1), p = 0.65. Median postoperative oral morphine equivalent utilisation was significantly higher in the erector spinae plane group (21 mg vs. 12 mg; p = 0.028). Itching was observed in 10% of patients who received erector spinae plane block and there was no difference in the incidence of significant nausea and vomiting. Patient satisfaction scores, and pain scores and opioid use at 24 h were similar. At 1 month, six (peri-articular injection) and eight (erector spinae plane block) patients reported persistent pain.

Erector spinae plane block was not superior to peri-articular injection for arthroscopic shoulder surgery.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 22 - 22
1 Dec 2022
Parker E AlAnazi M Hurry J El-Hawary R
Full Access

Clinically significant proximal junctional kyphosis (PJK) occurs in 20% of children treated with posterior distraction-based growth friendly surgery. In an effort to identify modifiable risk factors, it has been theorized biomechanically that low radius of curvature (ROC) implants (i.e., more curved rods) may increase post-operative thoracic kyphosis, and thus may pose a higher risk of developing PJK. We sought to test the hypothesis that EOS patients treated with low ROC (more curved rods) distraction-based treatment will have a greater risk of developing PJK as compared to those treated with high ROC (straighter) implants.

This is a retrospective review of prospectively collected data obtained from a multi-centre EOS database on children treated with rib-based distraction with minimum 2-year follow-up. Variables of interest included: implant ROC at index (220 mm or 500 mm), patient age, pre-operative scoliosis, pre-operative kyphosis, and scoliosis etiology. In the literature, PJK has been defined as clinically significant if revision surgery with superior extension of the upper instrumented vertebrae was performed.

In 148 scoliosis patients, there was a higher risk of clinically significant PJK with low ROC (more curved) rods (OR: 2.6 (95%CI 1.09-5.99), χ2 (1, n=148) = 4.8, p = 0.03). Patients had a mean pre-operative age of 5.3 years (4.6y 220 mm vs 6.2y 500 mm, p = 0.002). A logistic regression model was created with age as a confounding variable, but it was determined to be not significant (p = 0.6). Scoliosis etiologies included 52 neuromuscular, 52 congenital, 27 idiopathic, 17 syndromic with no significant differences in PJK risk between etiologies (p = 0.07). Overall, patients had pre-op scoliosis of 69° (67° 220mm vs 72° 500mm, p = 0.2), and kyphosis of 48° (45° 220mm vs 51° 500mm, p = 0.1). The change in thoracic kyphosis pre-operatively to final follow up (mean 4.0 ± 0.2 years) was higher in patients treated with 220 mm implants compared to 500 mm implants (220 mm: 7.5 ± 2.6° vs 500 mm: −4.0 ± 3.0°, p = 0.004).

Use of low ROC (more curved) posterior distraction implants is associated with a significantly greater increase in thoracic kyphosis which likely led to a higher risk of developing clinically-significant PJK in EOS patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 23 - 23
1 Dec 2022
Bouchard M Rezakarimi M Sadat M Reesor M Aroojis A
Full Access

Untreated clubfoot results in serious disability, but mild to moderate residual deformities can still cause functional limitations and pain. Measuring the impact of clubfoot deformities on children's wellbeing is challenging. There is little literature discussing the variability in outcomes and implications of clubfoot based on where geographically the child resides. Although the use of patient reported outcome measures (PROMs) is steadily growing in pediatric orthopaedics, few studies on clubfoot have incorporated them. The most widely used PROM for pediatric foot and ankle pathology is the Oxford Foot and Ankle Questionnaire for Children (OXFAQ-C) that include a physical, school and play, emotional and shoe wear domains. The aim of this study is to evaluate the validity and regional differences in scores of the OXFAQ-C questionnaire to identify functional disability in children with clubfoot in India and Canada.

This is a retrospective cohort study of children in Indian and Canadian clubfoot registries aged 5-16 years who completed >1 parent or child OXFAQ-C. The OXFAQ-C was administered once in 01/2020 to all patients in the Indian registry, and prospectively between 06/2019 and 03/2021 at initial visit, 3, 6, 12 months post-intervention, then annually for the Canadian patients. Demographic, clubfoot, and treatment data were compared to OXFAQ-C domain scores. Descriptive statistics and regression analysis were performed. Parent-child concordance was evaluated with Pearson's Coefficient of Correlation (PCC).

The cohort had 361 patients (253 from India, 108 from Canada). Non-idiopathic clubfoot occurred in 15% of children in India and 5% in Canada, and bilateral in 53% in India and 50% in Canada. Tenotomy rate was 75% in India and 62% in Canada. Median age at presentation was 3 months in India and 1 month in Canada. Mean Pirani score at presentation and number of Ponseti casts were 4.9 and 6.1 in India and 5.3 and 5.7 in Canada, respectively.

Parents reported lower scores in all domains the older the child was at presentation (p Canadians scored significantly lower for all domains (p < 0 .001), with the difference being larger for child-reported scores. The greatest difference was for physical domain. Canadian parents on average scored their child 6.21 points lower than Indian parents, and Canadian children scored a mean of 7.57 lower than Indian children.

OXFAQ-C scores differed significantly between Indian and Canadian children despite similar demographic and clubfoot characteristics. Younger age at presentation and tenotomy may improve OXFAQ-C scores in childhood. Parent-child concordance was strong in this population. The OXFAQ-C is an adequate tool to assess functional outcomes of children with clubfeet. Cultural validation of patient reported outcome tools is critical.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 7 - 7
1 Dec 2022
Nowak L Moktar J Henry P Schemitsch EH
Full Access

This study aimed to determine if multiple failed closed reductions (CRs) prior to fixation of distal radius fracture is associated with the odds of complication-related reoperation up to two years post fracture.

We identified all distal radius fracture patients aged 18 or older between the years of 2003-2016 in Ontario, Canada from linked administrative databases. We used procedural and fee codes to identify patients who underwent primary outpatient surgical fixation between 8 and 14 days post fracture, and grouped patients by the number of CRs they underwent prior to definitive fixation. We excluded patients who underwent fixation within 7 days of their fracture to exclude more complex fracture types and/or patients who required more immediate surgery. We grouped patients according to the number of CRs they underwent prior to definitive fixation. We used intervention and diagnostic codes to identify reoperations within two years of fixation. We used multi-level multivariable logistic regression to compare the association between the number of CRs and reoperation while accounting for clustering at the surgeon level and adjusting for other relevant covariables. We performed an age-stratified analysis to determine if the association between the number of CRs and reoperation differed by patient age.

We identified 5,464 patients with distal radius fractures managed with outpatient fixation between 8 and 14 days of their fracture. A total of 1,422 patients (26.0%) underwent primary surgical fixation (mean time to fixation 10.6±2.0 days), while 3,573 (65.4%) underwent secondary fixation following one failed CR (mean time to fixation 10.1±2.2 days, time to CR 0.3±1.2 days), and 469 (8.6%) underwent fixation following two failed CRs (mean time to fixation 10.8±2.2 days, time to first CR 0.0±0.1 days, time to second CR 4.7±3.0 days). The CR groups had higher proportions of female patients compared to the primary group, and patients who underwent two failed CRs were more likely to be fixed with a plate (vs. wires or pins). The unadjusted proportion of reoperations was significantly higher in the group who underwent two failed CRs (7.5%) compared to those who underwent primary fixation (4.4%), and fixation following one failed CR (4.9%). Following covariable adjustment, patients who underwent two failed CRs had a significantly higher odds of reoperation (odds ratio [OR] 1.72 [1.12-2.65]) compared to those who underwent primary fixation. This association appeared to worsen for patients over the age of 60 (OR 3.93 [1.76-8.77]). We found no significant difference between the odds of reoperation between patients who underwent primary fixation vs. secondary fixation following one failed CR.

We found that patients with distal radius fractures who undergo multiple CRs prior to definitive fixation have a significantly higher odds of reoperation compared to those who undergo primary fixation, or fixation following a single CR. This suggests that surgeons should offer fixation if indicated following a single failed CR rather than attempt multiple closed reductions. Prospective studies are required to confirm these findings.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 65 - 65
1 Dec 2022
Rosario R Coleman R Arruda E Grant J
Full Access

The goal of this study was to identify the effect of mismatches in the subchondral bone surface at the native:graft interface on cartilage tissue deformation in human patellar osteochondral allografts (OCA). Hypothesis: large mismatches in the subchondral bone surface will result in higher stresses in the overlying and surrounding cartilage, potentially increasing the risk of graft failure.

Nano-CT scans of ten 16mm diameter cadaveric patellar OCA transplants were used to develop simplified and 3D finite element (FE) models to quantify the effect of mismatches in the subchondral bone surface. The simplified model consisted of a cylindrical plug with a 16 mm diameter (graft) and a washer with a 16 mm inner diameter and 36 mm outer diameter (surrounding native cartilage). The thickness of the graft cartilage was varied from 0.33x the thickness of native cartilage (proud graft subchondral bone) to 3x the thickness of native cartilage (sunken graft subchondral bone; Fig. 1). The thickness of the native cartilage was set to 2 mm. The surface of the cartilage in the graft was matched to the surrounding native cartilage. A 1 MPa pressure was applied to the fixed patellar cartilage surface. Scans were segmented using Dragonfly and meshed using HyperMesh. FE simulations were conducted in Abaqus 2019.

The simplified model demonstrated that a high stress region occurred in the cartilage at the sharp bony edge between the graft and native subchondral bone, localized to the region with thinner cartilage. A 20% increase in applied pressure occurs up to 50μm away from the graft edge (primarily in the graft cartilage) for grafts with proud subchondral bone but varies little based on the graft cartilage thickness. For grafts with sunken subchondral bone, the size of the high stress region decreases as the difference between graft cartilage and native cartilage thickness decreases (Fig. 2-4), with a 200 μm high stress region occurring when graft cartilage was 3x thicker than native cartilage (i.e., greater graft cartilage thickness produces larger areas of stress in the surrounding native cartilage). The 3D models reproduced the key features demonstrated in the simplified model. Larger differences between native and graft cartilage thickness cause larger high stress regions. Differences between the 3D and simplified models are caused by heterogeneous cartilage surface curvature and thickness.

Simplified and 3D FE analysis confirmed our hypothesis that greater cartilage thickness mismatches resulted in higher cartilage stresses for sunken subchondral bone. Unexpectedly, cartilage stresses were independent of the cartilage thickness mismatch for proud subchondral bone. These FE findings did not account for tissue remodeling, patient variability in tissue mechanical properties, or complex tissue loading. In vivo experiments with full-thickness strain measurements should be conducted to confirm these findings. Mismatches in the subchondral bone can therefore produce stress increases large enough to cause local chondrocyte death near the subchondral surface. These stress increases can be reduced by (a) reducing the difference in thickness between graft and native cartilage or (b) using a graft with cartilage that is thinner than the native cartilage.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 67 - 67
1 Dec 2022
Cohen D Le N Zakharia A Blackman B Slawaska-Eng D de SA D
Full Access

To determine in skeletally mature patients with a traumatic, first-time, patellar dislocation, the effect of early MPFL reconstruction versus rehabilitation on the rate of recurrent patellar dislocations and functional outcomes.

Three online databases MEDLINE, EMBASE and PubMed were searched from database inception (1946, 1974, 1966 respectively), to August 20th, 2021, for literature addressing the management of patients sustaining acute first-time patellar dislocations. Data on redislocation rates, functional outcomes using the Kujala score, and complication rates were recorded. A meta-analysis was used to pool the mean postoperative kujala score as well as calculate the proportion of patients sustaining redislocation episodes using a random effects model. A risk of bias assessment was performed for all included studies using the MINORS and Detsky scores.

Overall, there were a total of 22 studies and 1705 patients included in this review. The pooled mean redislocation rate in 18 studies comprising 1409 patients in the rehabilitation group was 31% (95% CI 25%-36%, I2 = 65%). Moreover, the pooled mean redislocation rate in five studies comprising 318 patients undergoing early MPFL reconstruction was 7% (95% CI 2%-17%, I2 = 70%). The pooled mean postoperative Kujala anterior knee pain score in three studies comprising 67 patients in the reconstructive group was 91 (95% CI 84-97, I2 = 86%), compared to a score of 81 (95% CI 78-85, I2 = 78%) in 7 studies comprising 332 patients in the rehabilitation group. The reoperation rate was 9.0% in 936 patients in the rehabilitation group and 2.2% in 322 patients in the reconstruction group.

Management of acute first-time patellar dislocations with MPFL reconstruction resulted in a lower rate of redislocation and a higher Kujala score, as well as noninferiority with respect to complication rates compared to nonoperative treatment. The paucity of high-level evidence warrants further investigation in this topic in the form of well-designed and high-powered RCTs to determine the optimal management option in these patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 1 - 1
1 Dec 2022
Falsetto A Bohm E Wood G
Full Access

Recent registry data from around the world has strongly suggested that using cemented hip hemiarthroplasty has lower revision rates compared to cementless hip hemiarthroplasty for acute femoral neck hip fractures. The adoption of using cemented hemiarthroplasty for hip fracture has been slow as many surgeons continue to use uncemented stems. One of the reasons is that surgeons feel more comfortable with uncemented hemiarthroplasty as they have used it routinely. The purpose of this study is to compare the difference in revision rates of cemented and cementless hemiarthroplasty and stratify the risk by surgeon experience. By using a surgeons annual volume of Total Hip Replacements performed as an indicator for surgeon experience. The Canadian Joint Replacement Registry Database was used to collect and compare the outcomes to report on the revision rates based on surgeon volume.

This is a large Canadian Registry Study where 68447 patients were identified for having a hip hemiarthroplasty from 2012-2020. This is a retrospective cohort study, identifying patients that had cementless or cemented hip hemiarthroplasty. The surgeons who performed the procedures were linked to the procedure Total Hip Replacement. Individuals were categorized as experienced hip surgeons or not based on whether they performed 50 hip replacements a year. Identifying high volume surgeon (>50 cases/year) and low volume (<50 cases/year) surgeons. Hazard ratios adjusted for age and sex were performed for risk of revision over this 8-year span. A p-value <0.05 was deemed significant.

For high volume surgeons, cementless fixation had a higher revision risk than cemented fixation, HR 1.29 (1.05-1.56), p=0.017. This pattern was similar for low volume surgeons, with cementless fixation having a higher revision risk than cemented fixation, HR 1.37 (1.11-1.70) p=0.004 We could not detect a difference in revision risk for cemented fixation between low volume and high volume surgeons; at 0-1.5 years the HR was 0.96 (0.72-1.28) p=0.786, and at 1.5+ years the HR was 1.61 (0.83-3.11) p=0.159. Similarly, we could not detect a difference in revision risk for cementless fixation between low volume and high volume surgeons, HR 1.11 (0.96-1.29) p=0.161

Using large registry data, cemented hip hemiarthroplasty has a significant lower revision rate than the use of cementless stems even when surgeons are stratified to high and low volume. Low volume surgeons who use uncemented prostheses have the highest rate of revision. The low volume hip surgeon who cements has a lower revision rate than the high volume cementless surgeon. The results of this study should help to guide surgeons that no matter the level of experience, using a cemented hip hemiarthroplasty for acute femoral neck fracture is the safest option. That high volume surgeons who perform cementless hemiarthroplasty are not immune to having revisions due to their technique. Increased training and education should be offered to surgeons to improve comfort when using this technique.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 3 - 3
1 Dec 2022
Hoit G Khan R Chahal J Whelan D
Full Access

Multiligament knee injuries (MLKI) are rare and life-altering injuries that remain difficult to treat clinically due to a paucity of evidence guiding surgical management and timing. The purpose of this study was to compare injury specific functional outcomes following early versus delayed surgical reconstruction in MLKI patients to help inform timing decisions in clinical practice.

A retrospective analysis of prospectively collected data from patients with MLKIs at a single academic level 1-trauma center was conducted. Patients were eligible for inclusion if they had an MLKI, underwent reconstructive surgery either prior to 6wks from injury or between 12weeks and 2 years from injury, and had at least 12months of post-surgical follow-up. Patients with a vascular injury, open injuries or associated fractures were excluded. Study participants were stratified into early (<6wks from injury) and delayed surgical intervention (>12 weeks – 2 years from injury). The primary outcome was patient reported, injury specific, quality of life in the form of the Multiligament Quality of Life questionnaire (MLQOL) and its four domains (Physical Impairment, Emotional Impairment, Activity Limitations and Societal Involvement). We secondarily analyzed differences in the need for manipulation under anesthesia, and reoperation rates, as well as radiographic Kellgren Lawrence (KL) arthritis grades, knee laxity grading and range of motion at the most recent follow-up.

A total of 131 patients met our inclusion criteria, all having had surgery between 2006 and 2019. There were 75 patients in the early group and 56 in the delayed group. The mean time to surgery was 17.6 ± 8.0 days in the early group versus 279 ± 146.5 days in the delayed. Mean postoperative follow-up was 58 months. There were no significant differences between early and delayed groups with respect to age (34 vs. 32.8 years), sex (77% vs 63% male), BMI (28.3 vs 29.7 kg/m2), or injury mechanism (p>0.05). The early surgery group was found to include more patients with lateral sided injuries (n=49 [65%] vs. n=23 [41%]; p=0.012), a higher severity of Schenck Classification (p=0.024) as well as nerve injuries at initial presentation (n=35 [49%] vs n=8 [18%]; p<0.001). Multivariable linear regression analyses of the four domains of the MLQOL did not demonstrate an independent association with early versus delayed surgery status (p>0.05), when controlling for age, sex, Schenck classification, medial versus lateral injury, and nerve injury status. In terms of our secondary outcomes, we found that the early group underwent significantly more manipulations under anesthesia compare with the delayed group (n=24, [32%] vs n=8 [14%], p=0.024). We did not identify a significant difference in physical examination laxity grades, range of motion, KL grade or reoperation rates between groups (p>0.05).

We found no difference in patient reported outcomes between those who underwent early versus delayed surgery following MLKI reconstruction. In our secondary outcomes, we found significantly more patients in the early surgery group required a manipulation under anesthesia following surgery, which may indicate a propensity for arthrofibrosis after early MLKI reconstruction.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 71 - 71
1 Dec 2022
Gazendam A Ekhtiari S Ayeni OR
Full Access

Orthopaedic surgeons prescribe more opioids than any other surgical speciality. Opioids remain the analgesic of choice following arthroscopic knee and shoulder surgery. There is growing evidence that opioid-sparing protocols may reduce postoperative opioid consumption while adequately addressing patients’ pain. However, there are a lack of prospective, comparative trials evaluating their effectiveness. The objective of the current randomized controlled trial (RCT) was to evaluate the efficacy of a multi-modal, opioid-sparing approach to postoperative pain management in patients undergoing arthroscopic shoulder and knee surgery.

The NO PAin trial is a pragmatic, definitive RCT (NCT04566250) enrolling 200 adult patients undergoing outpatient shoulder or knee arthroscopy. Patients are randomly assigned in a 1:1 ratio to an opioid-sparing group or standard of care. The opioid-sparing group receives a three-pronged prescription package consisting of 1) a non-opioid prescription: naproxen, acetaminophen and pantoprazole, 2) a limited opioid “rescue prescription” of hydromorphone, and 3) a patient education infographic. The control group is the current standard of care as per the treating surgeon, which consists of an opioid analgesic. The primary outcome of interest is oral morphine equivalent (OME) consumption up to 6 weeks postoperatively. The secondary outcomes are postoperative pain scores, patient satisfaction, quantity of OMEs prescribed and number of opioid refills. Patients are followed at both 2 and 6 weeks postoperatively. Data analysts and outcome assessors are blinded to the treatment groups.

As of December 1, 2021 we have enrolled 166 patients, reaching 83% of target enrolment. Based on the current recruitment rate, we anticipate that enrolment will be completed by the end of January 2022 with final follow-up and study close out completed by March of 2022. The final results will be released at the Canadian Orthopaedic Association Meeting in June 2022 and be presented as follows. The mean difference in OME consumption was XX (95%CI: YY-YY, p=X). The mean difference in OMEs prescribed was XX (95%CI: YY-YY, p=X). The mean difference in Visual Analogue Pain Scores (VAS) and patient satisfaction are XX (95%CI: YY-YY, p=X). The absolute difference in opioid refills was XX (95%CI: YY-YY, p=X).

The results of the current study will demonstrate whether an opioid sparing approach to postoperative outpatient pain management is effective at reducing opioid consumption while adequately addressing postoperative pain in patients undergoing outpatient shoulder and knee arthroscopy. This study is novel in the field of arthroscopic surgery, and its results will help to guide appropriate postoperative analgesic management following these widely performed procedures.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 9 - 9
1 Dec 2022
Koucheki R Lex J Morozova A Ferri D Hauer T Mirzaie S Ferguson P Ballyk B
Full Access

Novel immersive virtual reality (IVR) technologies are revolutionizing medical education. Virtual anatomy education using head-mounted displays allows users to interact with virtual anatomical objects, move within the virtual rooms, and interact with other virtual users. While IVR has been shown to be more effective than textbook learning and 3D computer models presented in 2D screens, the effectiveness of IVR compared to cadaveric models in anatomy education is currently unknown. In this study, we aim to compare the effectiveness of IVR with direct cadaveric bone models in teaching upper and lower limb anatomy for first-year medical students.

A randomized, double-blind crossover non-inferiority trial was conducted. Participants were first-year medical students from a single University. Exclusion criteria included students who undertook prior undergraduate or graduate degrees in anatomy. In the first stage of the study, students were randomized in a 1:1 ratio to IVR or cadaveric bone groups studying upper limb skeletal anatomy. All students were then crossed over and used cadaveric bone or IVR to study lower limb skeletal anatomy. All students in both groups completed a pre-and post-intervention knowledge test. The educational content was based on the University of Toronto Medical Anatomy Curriculum. The Oculus Quest 2 Headsets (Meta Technologies) and PrecisionOS Anatomy application (PrecisionOS Technology) were utilized for the virtual reality component. The primary endpoint of the study was student performance on the pre-and post-intervention knowledge tests. We hypothesized that student performance in the IVR groups would be comparable to the cadaveric bone group.

50 first-year medical students met inclusion criteria and were computer randomized (1:1 ratio) to IVR and cadaveric bone group for upper limb skeletal anatomy education. Forty-six students attended the study, 21 completed the upper limb modules, and 19 completed the lower limb modules. Among all students, average score on the pre-intervention knowledge test was 14.6% (Standard Deviation (SD)=18.2%) and 25.0% (SD=17%) for upper and lower limbs, respectively. Percentage increase in students’ scores between pre-and post-intervention knowledge test, in the upper limb for IVR, was 15 % and 16.7% for cadaveric bones (p = 0. 2861), and for the lower limb score increase was 22.6% in the IVR and 22.5% in the cadaveric bone group (p = 0.9356).

In this non-inferiority crossover randomized controlled trial, we found no significant difference between student performance in knowledge tests after using IVR or cadaveric bones. Immersive virtual reality and cadaveric bones were equally effective in skeletal anatomy education. Going forward, with advances in VR technologies and anatomy applications, we can expect to see further improvements in the effectiveness of these technologies in anatomy and surgical education. These findings have implications for medical schools having challenges in acquiring cadavers and cadaveric parts.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 77 - 77
1 Dec 2022
Schneider P Bergeron S Liew A Kreder H Berry G
Full Access

Fractures of the humeral diaphysis occur in a bimodal distribution and represent 3-5% of all fractures. Presently, the standard treatment of isolated humeral diaphyseal fractures is nonoperative care using splints, braces, and slings. Recent data has questioned the effectiveness of this strategy in ensuring fracture healing and optimal patient function. The primary objective of this randomized controlled trial (RCT) was to assess whether operative treatment of humeral shaft fractures with a plate and screw construct provides a better functional outcome than nonoperative treatment. Secondary objectives compared union rates and both clinical and patient-reported outcomes.

Eligible patients with an isolated, closed humeral diaphyseal fracture were randomized to either nonoperative care (initial sugar-tong splint, followed by functional coaptation brace) or open reduction and internal fixation (ORIF; plate and screw construct). The primary outcome measure was the Disability Shoulder, Arm, Hand (DASH) score assessed at 2-, 6-, 16-, 24-, and 52-weeks. Secondary outcomes included the Short Musculoskeletal Functional Assessment (SMFA), the Constant Shoulder Score, range of motion (ROM), and radiographic parameters. Independent samples t-tests and Chi-squared analyses were used to compare treatment groups. The DASH, SMFA, and Constant Score were modelled over time using a multiple variable mixed effects model.

A total of 180 patients were randomized, with 168 included in the final analysis. There were 84 patients treated nonoperatively and 84 treated with ORIF. There was no significant difference between the two treatment groups for age (mean = 45.4 years, SD 16.5 for nonoperative group and 41.7, SD 17.2 years for ORIF group; p=0.16), sex (38.1% female in nonoperative group and 39.3% female in ORIF group; p=0.87), body mass index (mean = 27.8, SD 8.7 for nonoperative group and 27.2, SD 6.2 for ORIF group; p=0.64), or smoking status (p=0.74). There was a significant improvement in the DASH scores at 6 weeks in the ORIF group compared to the nonoperative group (mean=33.8, SD 21.2 in the ORIF group vs. mean=56.5, SD=21.1 in the nonoperative group; p < 0 .0001). At 4 months, the DASH scores were also significantly better in the ORIF group (mean=21.6, SD=19.7 in the ORIF group vs. mean=31.6, SD=24.6 in the nonoperative group; p=0.009. However, there was no difference in DASH scores at 12-month follow-up between the groups (mean=8.8,SD=10.9 vs. mean=11.0, SD=16.9 in the nonoperative group; p=0.39). Males had improved DASH scores at all timepoints compared with females. There was significantly quicker time to union (p=0.016) and improved position (p < 0 .001) in the ORIF group. There were 13 (15.5%) nonunions in the nonoperative group and four (4.7%) combined superficial and deep infections in the ORIF group. There were seven radial nerve palsies in the nonoperative group and five (a single iatrogenic) radial nerve palsies in the ORIF group.

This large RCT comparing operative and nonoperative treatment of humeral diaphyseal fractures found significantly improved functional outcome scores in patients treated surgically at 6 weeks and 4 months. However, the early functional improvement did not persist at the 12-month follow-up. There was a 15.5% nonunion rate, which required surgical intervention, in the nonoperative group and a similar radial nerve palsy rate between groups.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 79 - 79
1 Dec 2022
Halai M Pinsker E Daniels T Khoshbin A
Full Access

The prevalence of alcohol and opioids in severely injured patients has been widely reported from 30-80%. However, despite the increasing global misuse of stimulant drugs, there is a paucity of literature regarding the presence of stimulant drugs in trauma patients. The primary aim of this study was to define the prevalence of stimulant drugs that were detected in patients who presented to Level One Trauma Centers throughout North America, and their effect on length of stay and mortality.

Our triage criteria for admittance to the regional trauma centre are based on the recommendations by the American College of Surgeons Committee on Trauma, who now recommend toxicology screening on every patient. This was a retrospective analysis of data from the Trauma Quality Improvement Program, including all patients presenting emergently to participating Level 1 Trauma Centers from January 2017 to December 2018. A stimulant drug was defined as the detection of cocaine, amphetamine, or methamphetamine. Adults aged 18-64 years were included. Patient risk factors were included adjusted for in the analysis: age, sex, body mass index (BMI), alcohol screening results and smoking status. Univariate analysis was performed for all variables. Multivariable logistic regression and liner regression were used for mortality and length of stay, respectively.

Of a total of 110,561 patients included in the study, 15,958 patients (14.4%) had positive screens for stimulants. The average age in the stimulants cohort was 40.8 years, with a 77.6% male preponderance, BMI of 26.9, blood alcohol content of 0.07, and ISS of 11.3. The control cohort was comparable, though 71.1% male (p<0.001) Patients who tested positive for stimulants had 1.79 times (95% CI, 1.09-2.93) the odds of dying in the emergency department as the control group (p=0.02). Following transfer from the emergency department, the odds ratio for deaths in hospital (OR=1.02, 95% CI 0.90-1.15) was comparable to the control group (p=0.78). The mean length of stay was significantly higher in the stimulant group (2.84 days) compared to the control group (1.79 days) (p<.001). In the Intensive Care Unit, length of stay was 0.64 days in the stimulant group versus 1.65 in the control (p=0.48).

Stimulant misuse is a relevant issue in the trauma population, associated with a longer hospital stay and higher mortality in the emergency department. The continued routine drug screening of trauma patients may be beneficial in trauma centers, to implement preventative measures and optimise resource allocation.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 54 - 54
1 Dec 2022
Pereira Duarte M Joncas J Parent S Duval M Chemaly O Brassard F Mac-Thiong J Barchi S Labelle H
Full Access

There is a significant positive association between hours of brace wear and rate of success in the treatment of Adolescent Idiopathic Scoliosis (AIS). The abandon rate reported in the literature averages 18%. In a recent randomized trial conducted at our center; the abandon rate was 4%. We aim to document the abandon rate towards brace treatment during the COVID-19 pandemic and its impact on AIS progression.

We reviewed a database of AIS patients recruited between March and September 2020. Inclusion criteria were patients with AIS under brace treatment according to SRS criteria. The patients were divided in 2 cohorts: those with a self-reported good adherence to treatment and those who voluntarily abandoned treatment during follow-up. Patients with irregular adherence were excluded. Data analysis included age, gender, Risser stage, type of brace, Cobb angles at first visit and last follow-up (mean 11 months) and % of progression. Unpaired student tests were used for comparison.

154 patients met inclusion criteria. 20 patients were excluded due to irregular adherence. 89 patients (age: 12.1 y.o. ±1.4) reported good adherence to treatment, while 45 patients (age: 12.6 y.o. ±1.5) abandoned treatment, an abandon rate of 29%. The cohort of compliant patients started treatment with a mean main thoracic (MT) curve of 26° and finished with 27°. The mean difference between measurements was +0.65°±7.5; mean progression rate was −4.6%. However, patients who abandoned treatment started with a mean MT curve of 28° and finished with 33°, with a mean increase of +5°±8 and a mean progression rate of −11%. The differences between the 2 cohorts were statistically significant (p=0.002). Five (5) patients from the abandon group were offered for surgery because of curve progression.

The abandon rate of brace treatment in AIS significantly increased during the first wave of COVID-19 pandemic. Patients who voluntarily discontinued treatment had significant increases in curve progression and surgical indication rates.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 73 - 73
1 Dec 2022
Woolfrey M Bolton C Woolfrey K Warchuk D
Full Access

Despite total knee arthroplasty demonstrating high levels of success, 20% of patients report dissatisfaction with their result.

Wellness Stasis Socks are embedded with a proprietary pattern of neuro-receptor activation points that have been proven to activate a precise neuro-response, as according to the pattern theory of haptic perception, which stimulates improvements in pain and function.

Technologies that manipulate this sensory environment, such as textured insoles, have proven to be effective in improving gait patterns in patients with knee osteoarthritis. In regard to patients undergoing TKA using this new technology may prove beneficial as an adjunct to recovery as many patients suffer from further deficits to their proprioceptive system caused by ligamentous damage and alterations to mechanoreceptors during procedure. We hypothesized that the Wellness Stasis Socks are a safe, cost-effective and easily scalable strategy to support TKA patients through their recovery.

Double-blinded, placebo-controlled randomized trial. Randomization using a computer-generated program . All study coordinators, healthcare personel and patients were blinded to patient groups. All surgical procedures were conducted by the same technique and orthopaedic surgeon. Intervention group: Wellness Stasis socks containing receptor point-activation technology. Control group: indentical appearing Wellness Stasis socks without receptor point-activation technology. Sock use during the waking hours . All additional post-operative protocols remained consistent between groups including same facility physiotherapy . Additional modalities (ice machines, soft-tissue massages, acupuncture) were prohibited. WOMAC questionnaire completed at baseline, 2 weeks, and 6 weeks to assess pain, stiffness and physical function. G*Power software to determine minimum sample of 50 in each group. No patients were lost to follow up and all followed study protocol. Data analysis using SPSS software. P-values, effect sizes, and confidence intervals are reported to assess clinical relevance of the finding. Physical status classifications were compared using t-test. Within-subject and between-subject differences in the mean WOMAC were analyzed by ANOVA.

Cramer's V statistical analysis noted that other variables of Sex, BMI, ASA classification and Age were not statistically different between the control and intervention groups.

No statistical difference between groups in Preop Womac scores.

The data showed a consistent improvement in Womac scores for pain and stiffness at 2 weeks post op in the interventional group over the control group.

The womac scores assessing physical function showed a consistent improvement at both 2 and 6 weeks post op in the intervention group compared to the control group.

There were no complications in either group associated the sock use.

The intervention proved to be a low cost and safe additional intervention post operatively from TKA to help patients improve with regard to pain, stiffness and physical function.

This study suggests this modality can be added to the list of other commonly used post op interventions such as cryocuffs, physiotherapy, and relaxation techniques as safe post op interventions to help patients improve post op TKA and can act as an adjunct in providing non narcotic pain control .


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 77 - 77
1 Dec 2022
Spangenberg G Langohr GD Faber KJ Reeves J
Full Access

Total shoulder arthroplasty implants have evolved to include more anatomically shaped components that replicate the native state. The geometry of the humeral head is non-spherical, with the sagittal diameter of the base of the head being up to 6% (or 2.1-3.9 mm) larger than the frontal diameter. Despite this, many TSA humeral head implants are spherical, meaning that the diameter must be oversized to achieve complete coverage, resulting in articular overhang, or portions of the resection plane will remain uncovered. It is suspected that implant-bone load transfer between the backside of the humeral head and the cortex on the resection plane may yield better load-transfer characteristics if resection coverage was properly matched without overhang, thereby mitigating proximal stress shielding.

Eight paired cadaveric humeri were prepared for reconstruction with a short stem total shoulder arthroplasty by an orthopaedic surgeon who selected and prepared the anatomic humeral resection plane using a cutting guide and a reciprocating sagittal saw. The humeral head was resected, and the resulting cortical boundary of the resection plane was digitized using a stylus and an optical tracking system with a submillimeter accuracy (Optotrak,NDI,Waterloo,ON). A plane was fit to the trace and the viewpoint was transformed to be perpendicular to the plane. To simulate optimal sizing of both circular and elliptical humeral heads, both circles and ellipses were fit to the filtered traces using the sum of least squares error method. Two extreme scenarios were also investigated: upsizing until 100% total coverage and downsizing until 0% overhang.

Total resection plane coverage for the fitted ellipses was found to be 98.2±0.6% and fitted circles was 95.9±0.9%Cortical coverage was found to be 79.8 ±8.2% and 60.4±6.9% for ellipses and circles respectively. By switching to an ellipsoid humeral head, a small 2.3±0.3% (P < 0.001) increase in total coverage led to a 19.5±1.3%(P < 0.001) increase in cortical coverage. The overhang for fitted ellipses and circles was 1.7 ±0.7% and 3.8 ±0.8% respectively, defined as a percentage of the total enclosed area that exceeded the bounds of the humerus resections. Using circular heads results in 2.0 ±0.1% (P < 0.001) greater overhang. Upsizing until 100% resection coverage, the ellipse produced 5.4 ±3.5% (P < 0.001) less overhang than the circle. When upsizing the overhang increases less rapidly for the ellipsoid humeral head that the circular one (Figure 1). Full coverage for the head is achieved more rapidly when up-sizing with an ellipsoid head as well. Downsizing until 0% overhang, total coverage and cortical coverage were 7.5 ±2.8% (P < 0.001) and 7.9 ±8.2% (P = 0.01) greater for the ellipse, respectively. Cortical coverage exhibits a crossover point at −2.25% downsizing, where further downsizing led to the circular head providing more cortical coverage.

Reconstruction with ellipsoids can provide greater total resection and cortical coverage than circular humeral heads while avoiding excessive overhang. Elliptical head cortical coverage can be inferior when undersized. These initial findings suggest resection-matched humeral heads may yield benefits worth pursuing in the next generation of TSA implant design.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 62 - 62
1 Dec 2022
Milligan K Rakhra K Kreviazuk C Poitras S Wilkin G Zaltz I Belzile E Stover M Smit K Sink E Clohisy J Beaulé P
Full Access

It has been reported that 60-85% of patients who undergo PAO have concomitant intraarticular pathology that cannot be addressed with PAO alone. Currently, there are limited diagnostic tools to determine which patients would benefit from hip arthroscopy at the time of PAO to address intra-articular pathology. This study aims to see if preoperative PROMs scores measured by IHOT-33 scores have predictive value in whether intra-articular pathology is addressed during PAO + scope. The secondary aim is to see how often surgeons at high-volume hip preservation centers address intra-articular pathology if a scope is performed during the same anesthesia event.

A randomized, prospective Multicenter trial was performed on patients who underwent PAO and hip arthroscopy to treat hip dysplasia from 2019 to 2020. Preoperative PROMs and intraoperative findings and procedures were recorded and analyzed. A total of 75 patients, 84% Female, and 16% male, with an average age of 27 years old, were included in the study. Patients were randomized to have PAO alone 34 patients vs. PAO + arthroscopy 41 patients during the same anesthesia event. The procedures performed, including types of labral procedures and chondroplasty procedures, were recorded. Additionally, a two-sided student T-test was used to evaluate the difference in means of preoperative IHOT score among patients for whom a labral procedure was performed versus no labral procedure.

A total of 82% of patients had an intra-articular procedure performed at the time of hip arthroscopy. 68% of patients who had PAO + arthroscopy had a labral procedure performed. The most common labral procedure was a labral refixation which was performed in 78% of patients who had a labral procedure performed. Femoral head-neck junction chondroplasty was performed in 51% of patients who had an intra-articular procedure performed. The mean IHOT score was 29.3 in patients who had a labral procedure performed and 33.63 in those who did not have a labral procedure performed P- value=0.24.

Our findings demonstrate preoperative IHOT-33 scores were not predictive in determining whether intra-articular labral pathology was addressed at the time of surgery. Additionally, we found that if labral pathology was addressed, labral refixation was the most common repair performed. This study also provides valuable information on what procedures high-volume hip preservation centers are performing when performing PAO + arthroscopy.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 91 - 91
1 Dec 2022
Rizkallah M Aoude A Turcotte R
Full Access

Resection of the proximal femur raises several challenges to the orthopedic oncology surgeon. Among these is the re-establishment of the abductor mechanism that might impacts on hip function. Extent of tumor resection and surgeons’ preferences dictate the reconstruction method of the abductors. While some surgeons advocate the necessity of greater trochanter (GT) preservation whenever possible, others attempt direct soft tissues reattachment to the prosthesis. Sparse data in the literature evaluated the outcomes of greater trochanter fixation to the proximal femur megaprosthesis.

This is a retrospective monocentric study. All patients who received a proximal femoral replacement after tumor resection between 2005 and 2021 with a minimum follow-up of three months were included. Patients were divided into two groups: (1) those with preserved GT reattached to the megaprosthesis and (2) those with direct or indirect (tenodesis to fascia lata) abductor muscles reattachment. Both groups were compared for surgical outcomes (dislocation and revision rates) and functional outcomes (Trendelenburg gait, use of walking-assistive device and abductor muscle strength). Additionally patients in group 1 were subdivided into patients who received GT reinsertion using a grip and cables and those who got direct GT reinsertion using suture materials and studied for GT displacement at three, six and 12 months. Time to cable rupture was recorded and analyzed through a survival analysis.

Fifty-six patients were included in this study with a mean follow-up of 45 months (3-180). There were 23 patients with reinserted GT (group 1) and 33 patients with soft tissue repair (group 2). Revision rate was comparable between both groups(p=0.23); however, there were more dislocations in group 2 (0/23 vs 6/33; p=0.037). Functional outcomes were comparable, with 78% of patients in group 1 (18/23) and 73% of patients in group 2 (24/33) that displayed a Trendelenburg gait (p=0.76). In group 1, 70% (16/23) used walking aids compared to 79% of group 2 (27/33) (p=0.34). Mean abductor strength reached 2.7 in group 1 compared to 2.3 in group 2 (p=0.06). In group 1, 16 of the 23 patients had GT reinsertion with grip and cables. Median survival of cables for these 16 patients reached 13 months in our series. GT displacement reached a mean of two mm, three mm, and 11 mm respectively at three, six and 12 months of follow-up in patients with grip and cables compared to 12 mm, 24 mm and 26 mm respectively at the same follow-up intervals in patients with GT stand-alone suture reinsertion(p<0.05).

Although GT preservation and reinsertion did not improve functional outcomes after proximal femur resection and reconstruction with a megaprosthesis, it was significantly associated with lower dislocation rate despite frequent cable failure and secondary GT migration. No cable or grip revision or removal was recorded. Significantly less displacement was observed in patients for whom GT reattachment used plate and cables rather than sutures only. Therefore we suggest that GT should be preserved and reattached whenever possible and that GT reinsertion benefits from strong materials such as grip and cables.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 107 - 107
1 Dec 2022
Athar M Khan R Awoke A Daniels T Khoshbin A Halai M
Full Access

There is limited literature on the effects of socioeconomic factors on outcomes after total ankle arthroplasty (TAA). In the setting of hip or knee arthroplasty, patients of a lower socioeconomic status demonstrate poorer post-operative satisfaction, longer lengths of stay, and larger functional limitations. It is important to ascertain whether this phenomenon is present in ankle arthritis patients. This is the first study to address the weight of potential socioeconomic factors in affecting various socioeconomic classes, in terms of how they benefit from ankle arthroplasty.

This is retrospective cohort study of 447 patients who underwent a TAA. Primary outcomes included pre-operative and final follow-up AAOS pain, AAOS disability, and SF-36 scores. We then used postal codes to determine median household income using Canadian 2015 census data. Incomes were divided into five groups based on equal amounts over the range of incomes. This method has been used to study medical conditions such as COPD and cardiac disease. These income groups were then compared for differences in outcome measures. Statistical analysis was done using unpaired t-test.

A total of 447 patients were divided into quintiles by income. From lowest income to highest income, the groups had 54, 207, 86, 64, and 36 patients, respectively. The average time from surgery to final follow up was 85.6 months. Interestingly, we found that patients within the middle household income groups had significantly lower AAOS disability scores compared to the lowest income groups at final follow-up (26.41 vs 35.70, p=0.035). Furthermore, there was a trend towards middle income households and lower post-operative AAOS pain scores compared to the lowest income group (19.57 vs 26.65, p=0.063). There was also a trend toward poorer AAOS disability scores when comparing middle income groups to high income groups post-operatively (26.41 vs 32.27, p=0.058). Pre-operatively, patients within the middle-income group had more pain, compared to the lowest and the highest income groups. No significant differences in SF-36 scores were observed. There were no significant differences seen in middle income groups compared to the highest income group for AAOS pain post-operatively. There were no significant differences found in pre-operative AAOS disability score between income groups.

Patients from middle income groups who have undergone TAA demonstrate poorer function and possibly more pain, compared to lower and higher income groups. This suggests that TAA is a viable option for lower socioeconomic groups and should not be a source of discouragement for surgeons. In this circumstance there is no real disparity between the rich and the poor. Further investigation is needed to explore reasons for diminished performance in middle class patients.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 109 - 109
1 Dec 2022
Perez SD Britton J McQuail P Wang A(T Wing K Penner M Younger ASE Veljkovic A
Full Access

Progressive collapsing foot deformity (PCFD) is a complex foot deformity with varying degrees of hindfoot valgus, forefoot abduction, forefoot varus, and collapse or hypermobility of the medial column. In its management, muscle and tendon balancing are important to address the deformity. Peroneus brevis is the primary evertor of the foot, and the strongest antagonist to the tibialis posterior. Moreover, peroneus longus is an important stabilizer of the medial column. To our knowledge, the role of peroneus brevis to peroneus longus tendon transfer in cases of PCFD has not been reported.

This study evaluates patient reported outcomes including pain scores and any associated surgical complications for patients with PCFD undergoing isolated peroneus brevis to longus tendon transfer and gastrocnemius recession.

Patients with symptomatic PCFD who had failed non-operative treatment, and underwent isolated soft tissue correction with peroneus brevis to longus tendon transfer and gastrocnemius recession were included. Procedures were performed by a single surgeon at a large University affiliated teaching hospital between January 1 2016 to March 31 2021. Patients younger than 18 years old, or undergoing surgical correction for PCFD which included osseous correction were excluded.

Patient demographics, medical comorbidities, procedures performed, and pre and post-operative patient related outcomes were collected via medical chart review and using the appropriate questionnaires.

Outcomes assessed included Visual Analogue Scale (VAS) for foot and ankle pain as well as sinus tarsi pain (0-10), patient reported outcomes on EQ-5D, and documented complications.

Statistical analysis was utilized to report change in VAS and EQ-5D outcomes using a paired t-test. Statistical significance was noted with p<0.05.

We analysed 43 feet in 39 adults who fulfilled the inclusion criteria. Mean age was 55.4 ± 14.5 years old. The patient reported outcome mean results and statistical analysis are shown in Table one below. Mean pre and post-operative foot and ankle VAS pain was 6.73, and 3.13 respectively with a mean difference of 3.6 (p<0.001, 95% CI 2.6, 4.6). Mean pre and post-operative sinus tarsi VAS pain was 6.03 and 3.88, respectively with a mean difference of 2.1 (p<0.001, 95% CI 0.9, 3.4). Mean pre and post-operative EQ-5D Pain scores were 2.19 and 1.83 respectively with a mean difference of 0.4 (p=0.008, 95% CI 0.1, 0.6). Mean follow up time was 18.8 ± 18.4 months.

Peroneus brevis to longus tendon transfer and gastrocnemius recession in the management of symptomatic progressive collapsing foot deformity significantly improved sinus tarsi and overall foot and ankle pain. Most EQ-5D scores improved, but did not reach statistically significant values with the exception of the pain score. This may have been limited by our cohort size. To our knowledge, this is the first report in the literature describing clinical results in the form of patient reported outcomes following treatment with this combination of isolated soft tissue procedures for the treatment of PCFD.

For any figures or tables, please contact the authors directly.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 96 - 96
1 Dec 2022
Rizkallah M Ferguson P Basile G Werier JM Kim P Wilson D Turcotte R
Full Access

The reconstruction of peri-acetabular defects after severe bone loss or pelvic resection for tumor is among the most challenging surgical intervention. The Lumic® prosthesis (Implantcast, Buxtehude, Germany) was first introduced in 2008 in an effort to reduce the mechanical complications encountered with the classic peri-acetabular reconstruction techniques and to improve functional outcomes. Few have evaluated the results associated with the use of this recent implant.

A retrospective study from five Orthopedic Oncology Canadian centers was conducted. Every patient in whom a Lumic® endoprosthesis was used for reconstruction after peri-acetabular resection or severe bone loss with a minimal follow-up of three months was included. The charts were reviewed and data concerning patients’ demographics, peri-operative characteristics and post-operative complications was collected. Surgical and functional outcomes were also assessed.

Sixteen patients, 11 males and five females, were included and were followed for 28 months [3 – 60]. Mean age was 55 [17-86], and mean BMI reached 28 [19.6 – 44]. Twelve patients (75%) had a Lumic® after a resection of a primary sarcoma, two following pelvic metastasis, one for a benign tumor and one after a comminuted acetabular fracture with bone loss. Twelve patients (75%) had their surgery performed in one stage whereas four had a planned two-stage procedure. Mean surgical time was 555 minutes [173-1230] and blood loss averaged 2100 mL [500-5000]. MSTS score mean was 60.3 preoperatively [37.1 – 97] and 54.3 postoperatively [17.1-88.6]. Five patients (31.3%) had a cemented Lumic® stem. All patients got the dual mobility bearing, and 10 patients (62.5%) had the largest acetabular cup implanted (60 mm). In seven of these 10 patients the silver coated implant was used to minimize risk of infection. Five patients (31.3%) underwent capsular reconstruction using a synthetic fabric aiming to reduce the dislocation risk. Five patients had per-operative complications (31.3%), four were minor and one was serious (comminuted iliac bone fracture requiring internal fixation). Four patients dislocated within a month post-operatively and one additional patient sustained a dislocation one year post-operatively. Eight patients (50%) had a post-operative surgical site infection. All four patients who had a two-stage surgery had an infection. Ten patients (62.5%) needed a reoperation (two for fabric insertion, five for wash-outs, and three for implant exchange/removal). One patient (6.3%) had a septic loosening three years after surgery. At the time of data collection, 13 patients (81.3%) were alive with nine free of disease. Silver coating was not found to reduce infection risk (p=0.2) and capsuloplasty did not prevent dislocation (p=1).

These results are comparable to the sparse data published. Lumic® endoprosthesis is therefore shown to provide good functional outcomes and low rates of loosening on short to medium term follow-up. Infection and dislocation are common complications but we were unable to show benefits of capsuloplasty and of the use of silver coated implants. Larger series and longer follow-ups are needed.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 97 - 97
1 Dec 2022
Burke Z Lazarides A Gundavda M Griffin A Tsoi K Ferguson P Wunder JS
Full Access

Traditional staging systems for high grade osteosarcoma (Enneking, MSTS) are based largely on gross surgical margins and were developed before the widespread use of neoadjuvant chemotherapy. It is now well known that both microscopic margins and chemotherapy are predictors of local recurrence. However, neither of these variables are used in the traditional surgical staging and the precise safe margin distance is debated. Recently, a novel staging system utilizing a 2mm margin cutoff and incorporating precent necrosis was proposed and demonstrated improved prognostic value for local recurrence free survival (LRFS) when compared to the MSTS staging system. This staging system has not been validated beyond the original patient cohort. We propose to analyze this staging system in a cohort of patients with high-grade osteosarcoma, as well as evaluate the ability of additional variables to predict the risk of local recurrence and overall survival.

A retrospective review of a prospectively collected database of all sarcoma patients between 1985 and 2020 at a tertiary sarcoma care center was performed. All patients with high-grade osteosarcoma receiving neo-adjuvant chemotherapy and with no evidence of metastatic disease on presentation were isolated and analyzed. A minimum of two year follow up was used for surviving patients. A total of 225 patients were identified meeting these criteria. Univariate analysis was performed to evaluate variable that were associated with LRFS. Multivariate analysis is used to further analyze factors associated with LRFS on univariate analysis.

There were 20 patients (8.9%) who had locally recurrent disease. Five-year LRFS was significantly different for patients with surgical margins 2mm or less (77.6% v. 93.3%; p=0.006) and those with a central tumor location (67.9 v. 94.4; <0.001). A four-tiered staging system using 2mm surgical margins and a percent necrosis of 90% of greater was also a significant predictor of 5-year LRFS (p=0.019) in this cohort. Notably, percent necrosis in isolation was not a predictor of LRFS in this cohort (p=0.875). Tumor size, gender, and type of surgery (amputation v. limb salvage) were also analyzed and not associated with LRFS. The MSTS surgical margin staging system did not significantly stratify groups (0.066).

A 2mm surgical margin cutoff was predictive of 5-year LRFS in this cohort of patients with localized high-grade osteosarcoma and a combination of a 2mm margin and percent necrosis outperformed the prognostic value of the traditional MSTS staging system. Utilization of this system may improve the ability of surgeons to stage thier patients. Additional variables may increase the value of this system and further validation is required.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 98 - 98
1 Dec 2022
Yamaura L Monument M Skeith L Schneider P
Full Access

Surgical management for acute or impending pathologic fractures in metastatic bone disease (MBD) places patients at high-risk for post-operative venous thromboembolism (VTE). Due to the combination of malignancy, systemic cancer treatment, and surgical treatment, VTE-risk is increased 7-fold in patients with MBD compared to non-cancer patients undergoing the same procedure. The extent and duration of post-operative hypercoagulability in patients with MBD remains unknown and thromboprophylaxis guidelines were developed for non-cancer patients, limiting their applicability to address the elevated VTE-risk in cancer patients. Thrombelastography (TEG) analysis is a point-of-care test that measures clot formation, stabilization, and lysis in whole blood samples. The TEG parameter, maximal amplitude (MA), indicates clot strength and the threshold of ≥65 mm has been used to define hypercoagulability and predict VTE events in non-cancer patients requiring orthopaedic surgery. Therefore, this study aims to quantify the extent and duration of post-operative hypercoagulability in patients with MBD using serial TEG analysis.

Consecutive adults (≥18 years) with MBD who required orthopaedic surgery for acute or impending pathologic fractures were enrolled into this single-centre, prospective cohort study. Serial TEG analysis was performed onsite using a TEG®6s haemostasis analyzer (Haemonetics Corporation, Boston, MA) on whole blood samples collected at seven timepoints: pre-operatively; on post-operative day (POD) 1, 3, and 5; and at 2-, 6-, and 12-weeks post-operatively. Hypercoagulability was defined as MA ≥65 mm. Participants received standardized thromboprophylaxis for four weeks and patient-reported compliance with thromboprophylaxis was recorded. VTE was defined as symptomatic DVT or PE, or asymptomatic proximal DVT, and all participants underwent a screening post-operative lower extremity Doppler ultrasound on POD3. Descriptive statistics were performed and difference between pre-operative MA values of participants with VTE versus no VTE was evaluated using Student's t-test (p≤0.05).

Twenty-one participants (10 female; 47.6%) with a mean age of 70 ± 12 years were enrolled. Nine different primary cancers were identified amongst participants, with breast (23.8%), colorectal (19.0%), and lung cancer (14.3%) most frequently reported. Most participants (57.1%) were hypercoagulable pre-operatively, and nearly half remained hypercoagulable at 6- and 12-weeks post-operatively (47.1 and 46.7%, respectively). VTE occurred in 5 patients (23.8%) and mean MA was 68.1 ± 4.6 mm at the time of diagnosis. Mean pre-operative MA values were significantly higher (p=0.02) in patients who experienced VTE (68.9 ± 3.5 mm) compared to those who did not (62.7 ± 6.5 mm). VTE incidence was highest in the first week post-operatively, during which time four VTE events (80%) occurred. The proportion of patients in a hypercoagulable state increased at three consecutive timepoints, beginning on POD3 (85.0%), increasing on POD5 (87.5%), and peaking at 2-weeks post-operatively (88.9%).

Current thromboprophylaxis guidelines do not consider cancer-associated risk factors that contribute to increased VTE incidence and prescription duration may be inadequate to address prolonged post-operative hypercoagulability in patients with MBD. The high rate of VTE events observed and sustained hypercoagulable state indicate that thromboprophylaxis may be prematurely terminated while patients remain at high risk for VTE. Therefore, extending thromboprophylaxis duration beyond 4-weeks post-operatively in patients with MBD warrants further investigation.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 4 - 4
1 Dec 2022
Thatcher M Oleynik Z Sims L Sauder D
Full Access

Trapeziectomy with ligament reconstruction and tendon interposition (LRTI) with the flexor carpi radialis (FCR) tendon is one of the most common procedures for the treatment of thumb carpometacarpal (CMC) arthritis. An alternative method involves trapeziectomy alone (TA). The trapeziectomy with LRTI procedure was developed to theoretically improve biomechanical strength and hand function when compared to TA, which leaves an anatomical void proximal to the first metacarpal. The LRTI procedure takes longer to perform and includes an autologous tendon graft. The goal of this retrospective cohort study was to evaluate the clinical outcomes of trapeziectomy with or without LRTI at a minimum follow-up of 1 year.

A total of 43 adult patients who had underwent a total of 58 (TA=36, LRTI=22) surgical procedures for CMC arthritis participated in the study. This single surgeon retrospective cohort study sampled patients who underwent CMC arthroplasty with either TA or LRTI techniques between 2008 and 2020 with a minimum time of 1 year post-operatively. The patients were evaluated subjectively (The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire) and objectively (hand/thumb strength, pre/post-operative hand radiographs).

Both the TA and LRTI procedures provided good pain relief, motion, strength, and stability without any severe complications. There was no statistically significant difference in hand or thumb strength between the two groups. Radiography showed that compared to the preoperative status, the trapezial space decreased similarly between the two groups. There was no difference in size of collapse between TA and LRTI post-operatively.

The TA procedure had similar outcomes to LRTI and has the advantages of shorter surgical time, less incision length, and lower surgical complexity. TA provided equivalent trapezial space to LRTI after the operation. Future study should investigate these two procedures in a head-to-head comparison rather than longitudinally where both surgeon experience and time since procedure at follow-up may have impacted results.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 81 - 81
1 Dec 2022
Tong J Ajrawat P Chahal J Daud A Whelan DB Dehghan N Nauth A Hoit G
Full Access

To systematically review the literature regarding post-surgical treatment regimens on ankle fractures, specifically whether there is a benefit to early weightbearing or early mobilization (6 weeks form surgery).

The PubMed, MEDLINE and Embase databases were searched from inception to May 24, 2020. All randomized controlled trials that analyzed the effects of early weightbearing and mobilization following an ankle surgery were included. The primary outcome measure was the Olerud Molander Ankle Score (OMAS). Secondary outcomes included return to work (RTW) and complications. Logistic regression models with random intercepts were used to pool complication data by protocol clustered by study.

Twelve RCT's were included, with a total of 1177 patients (41.8 ± 8.4 years). In total, 413 patients underwent early weightbearing and early mobilization (35%), 338 patients underwent early weightbearing and delayed mobilization (29%), 287 patients underwent delayed weightbearing and early mobilization (24%), and 139 patients underwent delayed weightbearing and delayed mobilization (12%). In total, 81 patients had a complication (7%), including 53 wound complications (5%), 11 deep vein thromboses (1%), and 2 failures/nonunions (0%). Early ankle mobilization resulted in statistically significant increases in OMAS scores compared to delayed mobilization (3 studies [222 patients], 12.65; 95% CI, 7.07-18.22; P < 0.00001, I2 = 49%). No significant differences were found between early and delayed weightbearing at a minimum of one-year follow-up (3 studies [377 patients], 1.91; 95% CI, −0.73-4.55, P = 0.16, I2 = 0%). Patients treated with early weightbearing and early mobilization were at higher odds of facing any complication (OR 3.6, 95%CI 1.05-12.1, p=0.041) or wound complications (OR 4.9, 95%CI 1.3-18.8, p=0.022) compared to those with delayed weightbearing and delayed mobilization.

Early mobilization following surgical treatment for an ankle fracture resulted in improved ankle function scores compared to delayed mobilization regimens. There were no significant differences between early and delayed weightbearing with respect to patient reported outcomes. Patients who were treated with early mobilization and early weightbearing had an increased odds of postoperative complications.