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Volume 102-B, Issue SUPP_7 July 2020 The Canadian Orthopaedic Association (COA) and The International Combined Orthopaedic Research Societies (ICORS) Meeting, Montreal, Canada, June 2019. Part 2.

R. Paul N. Maldonado-Rodriguez S. Docter T. Leroux M. Khan C. Veillette A. Romeo

Reverse total shoulder arthroplasty (RSA) with glenoid bone grafting has become a common option for the management of significant glenoid bone loss and deformity associated with glenohumeral osteoarthritis. Despite the increasing utilization of this technique, our understanding of the rates of bone graft union, complications and outcomes are limited. The objectives of this systematic review are to determine 1) the overall rate of bone graft union, 2) the rate of union stratified by graft type and technique, 3) the reoperation and complication rates, and 4) functional outcomes, including range of motion (ROM) and functional outcome scores following RSA with glenoid bone grafting.

A comprehensive search of MEDLINE, Embase, and CINAHL databases was completed for studies reporting outcomes following RSA with glenoid bone grafting. Inclusion criteria included clinical studies with greater than 10 patients, and minimum follow up of one year. Studies were screened independently by two reviewers and quality assessment was performed using the MINORs criteria. Pooled and frequency-weighted means and standard deviations were calculated where applicable.

Overall, 15 studies were included, including nine retrospective case series (level IV), four retrospective cohort studies (level III), one prospective cohort study (level II) and one randomized control trial (level I). The entire cohort consisted of 555 patients with a mean age of 71.9±2.1 years and 70 percent female. The mean follow-up was 33.8±9.4 months. Across all procedures, 84.9% (N=471) were primary arthroplasties, and 15.1% (N=84) were revisions. The overall graft union rate was 89.2%, but was higher at 96.1% among studies that used autograft bone (9 studies, N=308). When stratified by technique, bone graft for the purposes of lateralization resulted in a 100% union rate (4 studies, N=139), while eccentric bone grafts used in asymmetric bone loss resulted in a lower union rate of 84.9% (10 studies, N=345). The overall revision rate was 6.5%, and was lowest following primary cases at 1.8% (11 studies, N=393). The pooled mean scapular notching rate was 20.1% (12 studies, N=497). Excluding notching, the pooled mean complication rate was 21.5% for all cases and 13% for primary cases (11 studies, N=393). When reported, there was significant improvement in post-operative ROM in all planes. There was also improvement in functional outcome scores, whereby the frequency-weighted mean Constant score increased from 25.9 to 67.2 (8 studies, N=319), ASES score increased from 34.7 to 75.2 (4 studies, N=142), and SST score increased from 2.1 to 7.6 (5 studies, N=196) at final follow up.

This review demonstrates that glenoid bone grafting with RSA results in good mid-term clinical and radiographic outcomes. Union rate appears to depend highly on graft type and technique, whereby the highest union rates were seen following the use of autograft bone for the purposes of lateralization. Interestingly, the union rate of autograft bone for the purposes of augmentation in eccentric bone loss is considerably lower and its impact on the long-term survivorship of the implant remains unknown.

J. Page S. Kerslake G. M. L. Buchko S. M. Heard L. A. Hiemstra M. Kopka

Anterior cruciate ligament (ACL) rupture with associated meniscal pathology commonly occurs in a young, active population. Preserving a greater proportion of the meniscus may improve long-term outcomes by maintaining shock absorption and knee stability. However, meniscal repair procedures involve longer healing and rehabilitation than meniscal debridement, which could affect return to work and activity. The purpose of this study was to examine the functional outcomes and quality of life scores through two years in patients undergoing ACL reconstruction (ACL-R) who had meniscal repair, meniscal debridement, or no meniscal damage at the time of reconstruction.

Data for 1814 skeletally mature patients with isolated primary ACL-R was prospectively collected at a single centre from January 2010 to December 2015. Functional testing of operative to non-operative limb performance was completed at one- and two-years following surgery and included single-leg balance, single-leg hop for distance, timed six-meter hop, triple-hop for distance, and triple cross-over hop for distance. ACL-Quality-of-life questionnaires (ACL-QoL) were completed pre-operatively and at 1- and 2-years post-operatively. Descriptive statistics were completed for patient demographics and intra-operative pathology. Unpaired t-tests using 95% confidence intervals were conducted to compare groups.

The patient cohort was 45% female, with a mean age of 31 years (SD 11, range 14–66). Meniscal injury was detected in 1229/1814 knees (67.8%). There were 729 debridements and 538 repairs performed. Graft choice was hamstring autograft in 85.8% of cases, bone-patellar-tendon-bone autograft in 2.5%, allograft in 10.1% and other graft types in 1.5%. Pre-operative ACL-QoL scores were 29 and 28.5 for knees without and with meniscal damage, respectively (p>0.05).

Of 1814 patients, 1269 (69.9%) completed the ACL-QoL at the two-year appointment, and 1225 (67.5%) completed the functional testing. At two years post-operative, patients with no meniscal damage at surgery demonstrated superior limb symmetry performance on triple-hop for distance compared to patients with meniscal damage (98.4% vs 97.1%, p < 0 .05, CI 0.1–2.5%). No other functional testing parameters showed statistical significance. There was no difference in functional outcome between patients undergoing an isolated meniscal repair versus debridement at one- or two-years. ACL-QoL scores were statistically significantly higher at one- and two-years post-operative for patients without meniscal damage (1-year: 73 vs 70.2, p < 0 .05, CI 0.51–5.1, 2-years: 79.2 vs 76.1, p < 0 .05, CI 0.79–5.4). ACL-QoL scores were minimally higher for isolated meniscal debridement compared to isolated meniscal repair at both time points (1-year: 71.4 vs 68, p < 0 .05, CI 0.4–6.4, 2-years: 78.3 vs 74, p < 0 .05, CI 1.3–7.3).

Functional outcomes do not differ at one or two years post-operatively for patients undergoing meniscal repair versus debridement concomitant with ACL-R. Quality of life scores were statistically significantly higher for the patients with no meniscal pathology at both one- and two-years post-operative. ACL-QoL scores were also statistically significantly different for the meniscal repair and debridement groups however these differences are unlikely to be clinically significant. Extended follow-up is needed to determine if the differences detected in ACL-QoL scores are sustained over time, as well as the long-term role of meniscal injury on functional outcomes.

J. Bowd P. Biggs C. Holt G. Whatling

Medial knee OA effects approximately 4.1 million people in England. Non-surgical strategies to lower knee joint loading is commonly researched in the knee OA literature as a method to alleviate pain and discomfort. Medial knee OA is much more prevalent than lateral knee OA due to the weight bearing line passing medial to the knee causing an external knee adduction moment (KAM). Numerous potential gait retraining strategies have been proposed to reduce either the first and/or the second peak KAM, including: toe-in gait, toe-out gait, lateral trunk lean and medial thrust gait. Gait retraining has been researched with little regard to the biomechanical consequences at the hip and ankle joints.

This systematic review aimed to establish whether gait retraining can reduce medial knee loading as assessed by first and second peak KAMs, establish what are the biomechanical effects a reduced KAM has on other lower limb joint biomechanics and outline patient/participant reported outcomes on how easy the gait retraining style was to implement. The protocol for this systematic review was registered with PROSPERO on the 23rd January 2018 (registration ID: CRD42018085738). 13 databases were searched by one author (J.B.B). Additionally, PROSPERO was searched for ongoing or recently completed systematic reviews. Risk of bias was assessed using the Downs and Black quality index.

Search: Group one consisted of keywords “walk” OR “gait”. Keywords “knee” OR “adduction moment” built up the second group. Group three consisted “osteoarthriti” OR “arthriti” OR “osteo arthriti”, OR “OA”. Group four included “hip” OR “ankle”. the searched results of each group were combined with conjunction “AND” in all fields.

Out of the eight different gait retraining strategies identified, trunk lean reduced first peak KAM the most, which was evaluated in 3 studies, reducing first peak KAM by 20%-65%. There was a lack of collective pelvic, hip and/or ankle joint biomechanical variables reported across all 11 studies. Of eight gait retraining styles identified, the strategy that reduced first peak KAM the most was an increased lateral trunk lean, which was evaluated in 3 different studies.

This is the first systematic review that has highlighted that there is limited evidence of the biomechanical consequences of a reduced knee joint load has on the pelvic, hip and/or ankle joints when undertaking gait retraining protocols. Future studies assessing gait retraining strategies should provide biomechanical outputs for other lower limb joints other than the knee joint, as well as providing participant perceptions on the level of difficulty the gait style is to perform.

S. Gautreau M. E. Forsythe O. Gould T. Mann R. Haley D. Canales

Early mobilization within the first 12 hours (day zero) of total joint arthroplasty (TJA) has been shown to reduce length of stay (LoS) without risking clinical outcomes, patient safety or satisfaction. The purpose of this study was to investigate associations between the degree of mobilization on day zero (i.e., standing at the bedside versus walking in the hallway) and LoS in TJA patients. In addition, we investigated predictors of LoS and day zero mobilization.

A retrospective cohort study was undertaken of the health records of patients in a community hospital setting who had an elective unilateral primary TJA between June 2015 and May 2017 and had mobilized on day zero.

The total sample was 283 patients (184 TKA and 99 THA) across four mobilization categories: Sat on beside (n = 76), Stood by bed/marched in place (n = 83), Walked in the room (n = 79), and Walked in hall (n = 45). Analysis of variance found no significant group differences in age, ASA score, Charlson Comorbidity Index score, anesthesia, surgeon, procedure type, pain medication, and patient reported symptoms recorded by physiotherapists. Significantly more women were in the Sat group and significantly more men were in the Hall group (p < .001). Patient reported symptoms of nausea and drowsiness were significantly greater for the Sat group (p < .001). LoS was also significantly different across the groups. Post hoc Tukey comparisons found the Walked Hall group had significantly shorter LoS (M = 2.7 days) than the Sat group (M = 3.9, p < .001), Stood group (M = 3.4, p = .011), and the Walked Room group (M = 3.5, p = .004).

A hierarchical regression was performed to determine predictors of LoS. Block 1 consisted of demographic, medical status, and patient reported symptoms as variables. Mobilization was entered in Block 2. The first model was significant (p < .001) and explained 24% of variance in LoS. The final model was also significant (p < .001), accounting for a total of 26% of the variance in LoS. Thus, block 2 (i.e., mobilization) accounted for a small but significant 2% incremental variance (p = .008) beyond the block 1 variables in the prediction of LoS. With mobilization added, only male gender (p = .002), lower BMI (p = .026), and lower ASA scores (p = .006) remained significant predictors of shorter LoS, and the predictive ability of several of the block 1 variables were reduced to non-significant levels. A simultaneous regression model was then used to predict degree of mobilization. The model accounted for 24% of the variance in mobilization (p < .001). Variables significantly associated with a greater degree of mobilization included: younger age, male gender, lower BMI, and fewer symptoms, namely nausea, numbness, lightheadedness, and drowsiness.

This study found length of stay was shorter when patients mobilized farther on the day of surgery. Some factors predictive of mobilization may be modifiable. Focusing on symptom management could increase opportunities for farther mobilization on the day of surgery, and thus decrease length of stay.

E. Schaeffer G. Sanatani E. Habib J. Bone K. Mulpuri

Paediatric femoral fractures are a common result of significant trauma, and always require intervention. Hip spica casting, traction, and surgical fixation can all be used to treat these fractures. This variety in treatment options leads to a vast potential for variability in management decisions among surgeons and has prevented effective comparative studies to show which treatment methods provide optimal outcomes for patients. The purpose of this study was to identify practice variability in management and follow-up and assess patient outcomes to aid in the development of a comprehensive, prospective, evidence-based pathway for the management of paediatric femoral fractures.

A retrospective chart review was performed of all patients treated surgically for isolated femoral fractures during a six year period at a single tertiary care paediatric centre. Patients were identified from a surgical database and were included if there was no pre-existing pathology and no history of previous femoral fracture. Demographic data, operative details, post-operative management, and clinical outcomes were collected. Radiographic images and reports were analyzed to determine fracture classification and imaging parameters. Variability in treatment among eight surgeons was assessed, including number of follow-up appointments and length of follow-up. Patient demographics and follow up measures were summarised for each surgeon and between surgeon variability was assessed with linear models.

In total, 138 femoral fractures in 134 patients (101 male, 33 female) were included in analysis. Of these patients, 55 had right femoral fractures, 76 left, and three bilateral (one bilateral patient had three distinct femoral fractures). Of 138 total fractures, 131 were of the diaphysis of the femur. 14 patients sought initial surgical treatment at our institution but received follow-up management elsewhere. Across all patients, median follow-up time was 32.8 weeks (0–201.4) with a median of three follow-up visits (0–26) in that period. Mean number of follow-up clinic visits ranged from 3 to 4.8 among surgeons, and mean length of follow-up ranged from 31.8 to 62.3 weeks.

No significant differences in follow-up between surgeons were found, but small sample sizes are a likely contributing factor. Summary statistics show large ranges in most variables and differences in patient demographics between surgeon groups. The large ranges in follow-up time and visit number suggest a lack of consensus on optimal management for paediatric femoral fractures. Further prospective study examining long-term functional and quality of life outcomes will be required to identify and develop optimized management guidelines.

O. Paserin R. Garbi A. Hodgson A. Cooper K. Mulpuri

Dynamic 2D sonography of the infant hip is a commonly used clinical procedure for developmental dysplasia of the hip (DDH) screening. It however has been found to be unreliable with some studies reporting associated misdiagnosis rates of up to 29%. In a recent systematic review, Charlton et al. examined dynamic ultrasound (US) screening for hip instability in the first six weeks after birth and found current best practices for such early screening techniques to be divergent between international institutions in terms of clinical scanning protocols. Such protocols include: the appropriate scanning plane and US probe position (e.g. coronal, transverse, lateral, anterior), DDH diagnostic metrics (e.g. femoral head coverage, alpha angle), appropriate patient age when scanning, and follow up procedures. To improve reliability of diagnosis and to help in standardizing diagnosis across different raters and health-centers, we propose an automated method for dynamically assessing hip instability using 3D US.

38 infant hips from 19 patients were scanned with B-mode 3D US by a paediatric orthopaedic surgeon and two technologists from the radiology department at a paediatric tertiary care centre. To quantify hip assessment, we proposed the use of femoral head coverage variability (ΔFHC3D) within 3D US volumes collected during a sequence of US scans (one at rest, and another with posterior stress applied to the joint as maneuvered during a dynamic assessment). We used phase symmetry image features to localize the ilium's vertical cortex and a random forest classifier to identify the location of the femoral head.

The proposed ΔFHC3D provided good repeatability with an average test-retest ICC measure of 0.70 (95% confidence interval: 0.35 to 0.87, F(21,21) = 7.738, p<.001). The mean difference of ΔFHC3D measurements was 0.61% with a SD of 4.05%.

Since the observed changes in ΔFHC3D start near 0% and range up to about 18% from stable to mildly unstable hips in this cohort, the mean difference and standard deviation of ΔFHC3D measurements observed suggest that the proposed metric and technique likely have sufficient resolution and repeatability to quantify differences in hip laxity. The long-term significance of this approach to evaluating dynamic assessments may lie in increasing early diagnostic accuracy in order to prevent dysplasia remaining undetected prior to manifesting itself in early adulthood joint disease.

E. Schaeffer T. Teo A. Cherukupalli A. Cooper A. Aroojis W. Sankar V. Upasani S. Carsen K. Mulpuri J. Bone C. W. Reilly

The Gartland extension-type supracondylar humerus fracture is the most common elbow fracture in the paediatric population. Depending on fracture classification, treatment options range from nonoperative treatment such as taping, splinting or casting to operative treatments such as closed reduction and percutaneous pinning or open reduction. Classification variability between surgeons is a potential contributing factor to existing controversy over nonoperative versus operative treatment for Type II supracondylar fractures. The purpose of this study was to investigate levels of agreement in classification of extension-type supracondylar humerus fractures using the Gartland classification system.

A retrospective chart review was conducted on patients aged 2–12 years who had sustained an extension-type supracondylar fracture and received either operative or nonoperative treatment at a tertiary children's hospital. De-identified baseline anteroposterior (AP) and lateral plain elbow radiographs were provided along with a brief summary of the modified Gartland classification system to surgeons across Canada, United States, Australia, United Kingdom and India. Each surgeon was blinded to patient treatment and asked to classify the fractures as Type I, IIA, IIB or III according to the classification system provided. A total of 21 paediatric orthopaedic surgeons completed one round of classification, of these, 15 completed a second round using the same radiographs in a reshuffled order. Kappa values using pre-determined weighted kappa coefficients were calculated to assess interobserver and intraobserver levels of agreement.

In total, 60 sets of baseline elbow radiographs were provided to survey respondents. Interobserver agreement for classification based on the Gartland criteria between surgeons was a mean of 0.68, 95% CI [0.67, 0.69] (0.61–0.80 considered substantial agreement). Intraobserver agreement was a mean of 0.80 [0.75, 0.84]. (0.61–0.80 substantial agreement, 0.81–1 almost perfect agreement).

Radiographic classification of extension-type supracondylar humerus fractures at baseline demonstrated substantial agreement both between and within surgeon raters. Levels of agreement are substantial enough to suggest that classification variability is not a major contributing factor to variability in treatment between surgeons for Type II supracondylar fractures. Further research is needed to compare patient outcomes between nonoperative and operative treatment for these fractures, so as to establish consensus and a standardized treatment protocol for optimal patient care across centres.

C. Goplen L. Beaupre C. A. Jones D. Voaklander T. Churchill S. H. H. Kang

Up to 40% of patients are using opioids at the time of joint replacement surgery in the USA despite emerging evidence suggesting opioids are ineffective for chronic non-cancer pain. Our primary objective was to determine if preoperative opioid use among patient awaiting total knee arthroplasty (TKA) was associated with worse patient-reported outcomes (PRO) measures at one-year follow-up when compared to non-opioid users, after adjusting for age, gender, and comorbidities.

The study linked Alberta's Pharmacy Information Network (PIN) data with prospectively collected Alberta Bone and Joint Health Repository administrative data (medical and PRO data) for patients who underwent primary TKA in Alberta from 2013–2015. The PIN contains prescribing information from physician offices and pharmacies across Alberta. Preoperative ‘opioid users’ were defined as having 90-days of consistent opioid use in the 180-days prior TKA, and ‘opioid-exposed’ subjects had recorded opioid prescriptions in the 180-days prior to TKA, but did not meet the definition of an opioid user. Those with no opioid-exposure in the 180-days pre-TKA were deemed a ‘non-opioid user’. We used multiple linear regression to examine how preoperative opioid use (opioid user, opioid-exposed, non-opioid user) impacted Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores at one year after TKA after adjusting for confounding variables. These included age, sex, preoperative WOMAC scores, comorbidities including depression, diabetes, obesity, stroke, pulmonary disease, renal disease, cardiac disease, liver disease, and overall comorbid burden.

Of the 2182 unique cases identified, 151 (7%) were opioid users, 527 (24%) opioid-exposed and 1504 (69%) non-opioid user. Opioid users were more likely to be prescribed strong opioids (e.g., hydromorphone, oxycodone) compared to with opioid-exposed subjects (p < 0 .001) and had a median morphine equivalent dose of 30.7 mg/day compared with the opioid-exposed group (2.2 mg/day, p < 0 .001) in the 180-days prior to TKA. Opioid users, in the 180-days prior to TKA had an active opioid prescription for a mean duration of 153 days (95CI 149, 157) within the 180-days prior to TKA, compared to 34 days (95CI 32, 37) for opioid-exposed (p < 0 .001). In the parsimonious pain and function models, opioid use, lower preoperative WOMAC score, depression, and obesity were associated with worse one-year pain and function. Patients prescribed preoperative opioids had worse WOMAC scores one-year after TKA respectively when compared to non-opioid users, after adjusting for other factors (opioid user pain score: −9.5, function score: −9.4, opioid exposed pain score: −2.6, function score: −3.6, p < 0 .001 for all). Further, opioid users with a concomitant diagnosis of depression had significantly worse one-year postoperative WOMAC scores when compared to non-depressed non-opioid users (scores −14, p < 0 .001 for both pain and function).

In Alberta, 31% of patients were prescribed opioids within 180-days before TKA, preoperative opioid use was associated with worse one-year postoperative WOMAC pain and function scores relative to non-opioid users. Our results suggest that strategies to reduce preoperative opioid use could improve patient outcomes after TKA, and support the most recent Canadian opioid prescribing guidelines that attempt to minimize opioid use for chronic conditions such as arthritis.

R. Y. Rampersaud A. Perruccio C. Yip J. D. Power M. Canizares E. Badley S. J. Lewis

Up to one-third of patients experience limited benefit following surgical intervention for LS-OA. Thus, identifying contributing factors to this is important. People with OA often have multijoint involvement, yet this has received limited attention in this population. We documented the occurrence and evaluated the influence of multijoint symptoms on outcome following surgery for LS-OA.

141 patients undergoing decompression surgery+/−fusion for LS-OA completed the Oswestry Disability Index (ODI) pre- and 12-months post-surgery. Also captured pre-surgery: age, sex, education, BMI, smoking, depressive symptoms and comorbidities. Any joints with “pain/stiffness/swelling most days of the month” were indicated on a homunculus. A symptomatic joint site count (e.g. one/both knees= one site), excluding the back, was derived (range zero to nine) and considered as a predictor of magnitude of ODI change, and likelihood of achieving minimally clinically important improvement in ODI (MCID=12.8) using multivariable adjusted linear and log-Poisson regression analyses.

Mean age: 66 years (range:42–90), 46% female. 76% reported one+ joint site other than the back, 43% reported three+, and nearly 10% reported six+. (< MCID) for those with three sites, and four units for those with six+ sites. Associated with a greater likelihood of not achieving MCID were increasing joint count (11% increase per site (p=0.012)), higher BMI, current/former smoker, and worse baseline ODI tertile.

Results suggest there is more than just the back to consider to understand patient-reported back outcomes. Multijoint symptoms directly contribute to disability, but there is potential they may contribute to systemic, largely inflammatory, effects in OA as well.

R. Y. Rampersaud P. Cram B. E. Landon J. Matelski V. Ling A. Perruccio M. Paterson

Spine surgery is common and costly. Researchers and policy makers believe that utilization of spine surgery in the US is significantly higher than in other industrialized countries. Although within-country variation in spine surgery utilization is well studied, there has been little exploration of variation in spine surgery between countries.

We used population level administrative data from Ontario (years 2011–2015) and New York (2011–2014) to identify all adults who underwent inpatient spinal decompression or fusion surgery. We compared Ontario and New York with respect to patient demographics and the percentage of hospitals performing spine surgery. We compared rates of decompression and fusion surgery (procedures per-10,000 population per-year) in Ontario and New York for all procedures, emergent procedures alone, and elective procedures and after stratifying by patient age.

Patients in Ontario were older than patients in New York for decompression (mean age 58.8 vs. 51.3 years, P<.001) and fusion (58.1 vs. 54.9, P<.001). A smaller percentage of hospitals in Ontario performed decompression or fusion compared to New York (decompression, 26.1% in Ontario vs 54.9% in New York: fusion 15.2% vs 56.7%, both P<.001). Overall, utilization of spine surgery in Ontario was 6.6 procedures per-10,000 population per-year and in New York was 18 per-10,000 per-year (P<.001). Ontario-New York differences in utilization were small for emergent cases (2 per-10,000 in Ontario vs. 2.8 in New York, P<.001), but large for elective cases (4.6 vs 15.2, P<.001). In analyses stratified by surgical subtype, differences in utilization of decompression in New York and Ontario were relatively modest (2.4 vs 3.1, P<.001), while utilization of fusion was approximately 400% higher in New York than Ontario (15.7 vs 3.5, P<.001). Further analysis demonstrated that the New York-Ontario difference in utilization was substantially larger among younger patients and smaller for older patients. For example, utilization of spine procedures in New York was 340% greater than Ontario for patients less-than 50 years of age (11.7 vs 3.4), but only 25% greater in patients age 80 and above (10 vs 12.6).

After adjusting for patient demographics, hospital LOS and surgical urgency, differences in mortality in Ontario and New York were not significant for either decompression or fusion. In adjusted analyses differences in hospital LOS were slightly greater for decompression in Ontario, but similar for fusion and readmission rates in Ontario were significantly lower than in New York.

In conclusion, we found significantly lower utilization of spine surgery in Ontario when compared to New York. The difference in utilization was attributable to less elective fusion surgery, primarily in younger (i.e. non-Medicare) patients. These findings can serve inform broader spine surgery policy reforms in both jurisdictions.

E. Schaeffer A. Ghoto D. Ahmad E. Habib K. Mulpuri

Systematic reviews (SR) can provide physicians with effective means to further strengthen their practice and identify gaps in clinical knowledge. The focus of any SR is to identify the current state of evidence for a given treatment or condition, with the hopes of providing the best interventional methods physicians can base their practice on. In paediatric orthopaedics, high-level studies are lacking, thus potentially limiting the effectiveness of SRs in the field. There isn't one specific way to qualify research on its effectiveness, but there has been gradual enhancement in finding ways to identify a successful and reproducible study. The purpose of this study was to evaluate the quality of paediatric orthopaedic SRs, and highlight aspects of these SRs that have contributed to improved outcomes.

A literature review was performed in EMBASE, MEDLINE and Cochrane databases to identify pre-existing systematic reviews that have been published in five well-known orthopaedic journals between 2007 and 2017. SRs were included if the study population was between 0 and 18 years of age. Selected articles had an AMSTAR checklist applied in order to score the studies on their quality and methodology. Articles were independently reviewed by two reviewers to determine the extent of AMSTAR guidelines fulfillment.

A total of 40 SRs were identified and reviewed, 20 of which partially or completely fulfilled AMSTAR guidelines. There was no disagreement between reviewers as to which of the analyzed articles have successfully reflected the checklist.

Only 20/40 SRs analyzed at least partially fulfilled AMSTAR guidelines. One of the weaknesses identified in the reviewed papers so far is the lack of justification for the chosen study designs for SRs and what strategy was used to decide on the exclusion of articles. There needs to be clear-cut criteria that mark studies to be included and excluded in a comprehensive systematic review. Further improvements are required to ensure that full details on the involvement of papers and the success rates regarding each interventional method are included in order to strengthen the quality of SRs across the paediatric orthopaedic literature.

G. Dervin T. D. V. Cooke

Integrated Regional Orthopaedic (MSK) Assessment clinics (ROAC) are now mandated in many provinces for the assessment and triage of patients referred for total joint arthroplasty (TJA). Their introduction underscores the lack of means for Primary Care Physicians (PCP) to appropriately refer patients for surgical consideration. Thus, problems arise when patients who are clear candidates for surgery are subject to a significant extra step in the care pathway by attending a ROAC while those who have insufficient problems are also seen, contributing to costs and crowding the access portal. We postulated that a patient reported outcome measure, decision aid combined with a validated grading of a weight bearing knee X-ray would provide an inexpensive yet effective tool to significantly improve the referral process for Knee OA (compared with the current mechanism).

To date we have enrolled two hundred and forty-five consenting patients to the study, all referred by their PCP to the ROAC with a diagnosis of symptomatic Knee Osteoarthritis. All patients were evaluated as per the current ROAC protocol which included a medical history, physical examination and an X-ray (standing AP, lateral and patella-femoral skyline). Prior to the visit, subjects were sent a copy of a patient decision aid, Oxford Knee Score (OKS) and requested to answer whether their current clinical status described as Patient Acceptable Symptom State (PASS2) was acceptable. All radiographs were analyzed and scored for OA severity using the validated grading from 0 – 13.

Of the 245 cases, 200 completed OKS and PASS2 uestionnaires and had standing X-rays for evaluation (only 120 completed the decision aid and these were left out of this report). Of the 200 included cases, 104 were referred from the ROAC to see a surgeon. In analysis, we found that a self-reported PASS 2 answer NO and an AP X-ray graded at 6 or above predicted over 75% of those patients that were referred. This represents a 3.4 greater likelihood of referral using this simple analysis. The OKS did not modify this prediction.

Thus, use of a validated grading of a standing AP X-ray along with a response, ‘readiness for surgery’ indicated 75% of patients appropriate for surgical consideration. Patients with less severe gradings are likely being unnecessarily referred to ROAC leading to overuse of scarce resources, crowding the access and adding to costs, others, who score higher, are being needlessly delayed. The ability to discreetly screen for the best possible candidates should be a continued focus of ROAC and will lead to improved use of expensive resources, overall patient care and satisfaction and the provision of tools to the PCP for appropriate referral.

E. Schaeffer N. Hooper N. Banting R. Pathy A. Cooper C. W. Reilly K. Mulpuri

Fractures through the physis account for 18–30% of all paediatric fractures, leading to growth arrest in 5.5% of cases. We have limited knowledge to predict which physeal fractures result in growth arrest and subsequent deformity or limb length discrepancy. The purpose of this study is to identify factors associated with physeal growth arrest to improve patient outcomes.

This prospective cohort study was designed to develop a clinical prediction model for growth arrest after physeal injury. Patients < 1 8 years old presenting within four weeks of injury were enrolled if they had open physes and sustained a physeal fracture of the humerus, radius, ulna, femur, tibia or fibula. Patients with prior history of same-site fracture or a condition known to alter bone growth or healing were excluded. Demographic data, potential prognostic indicators and radiographic data were collected at baseline, one and two years post-injury.

A total of 167 patients had at least one year of follow-up. Average age at injury was 10.4 years, 95% CI [9.8,10.94]. Reduction was required in 51% of cases. Right-sided (52.5%) and distal (90.1%) fractures were most common. After initial reduction 52.5% of fractures had some form of residual angulation and/or displacement (38.5% had both). At one year follow-up, 34 patients (21.1%) had evidence of a bony bridge on plain radiograph, 10 (6.2%) had residual angulation (average 12.6°) and three had residual displacement. Initial angulation (average 22.4°) and displacement (average 5.8mm) were seen in 16/34 patients with bony bridge (48.5%), with 10 (30.3%) both angulated and displaced. Salter-Harris type II fractures were most common across all patients (70.4%) and in those with bony bridges (57.6%). At one year, 44 (27.3%) patients had evidence of closing/closed physes.

At one year follow-up, there was evidence of a bony bridge across the physis in 21.1% of patients on plain film, and residual angulation and/or displacement in 8.1%. Initial angulation and/or displacement was present in 64.7% of patients showing possible evidence of growth arrest. The incidence of growth arrest in this patient population appears higher than past literature reports. However, plain film is an unreliable modality for assessing physeal bars and the true incidence may be lower. A number of patients were approaching skeletal maturity at time of injury and any growth arrest is likely to have less clinical significance in these cases. Further prospective long-term follow-up is required to determine the true incidence and impact of growth arrest.

M. Marquis S. Kerslake L. A. Hiemstra S. M. Heard G.M.L. Buchko

The aim of an anterior cruciate ligament (ACL) reconstruction is to regain functional stability of the knee following ACL injury, ideally allowing patients to return to their pre-injury level of activity. The purpose of this study was to assess clinical, functional and patient-reported outcomes following primary ACL reconstruction with hamstring autograft.

A prospective case-series design (n=1610) was used to gather data on post-operative ACL graft laxity, functional testing performance and scores on the ACL quality of life (ACL-QOL) questionnaire. Demographic data were collected for all patients. Post-operative ACL laxity assessment using the Lachman and Pivot-shift tests was completed independently on each patient by a physiotherapist and an orthopaedic surgeon at the 6-, 12- and 24-months post-operative appointments. A battery of functional tests was also assessed including single leg Bosu balance, and 4 single-leg hop tests. The hop tests provided a comparative assessment of limb-to-limb function. Patients completed the ACL-QOL at all time points. The degree and frequency of post-operative laxity was calculated. A Spearman's rank correlation matrix was undertaken to assess for relationships between post-operative laxity, functional test performance, and the ACL-QOL scores. A linear regression model was used to assess for relationships between the ACL-QOL scores, as well as the functional testing results, and patient demographic factors.

ACLR patients were 55% male, with a mean age of 29.7 years (SD=10.4), mean BMI of 25 (SD=3.9), and mean Beighton score of 3.3 (SD=2.5). At clinical assessment 2-years post-operatively, 20.6% of patients demonstrated a positive Lachman test and 7.7% of patients demonstrated a positive Pivot-shift test. The mean ACL-QOL score was 28.6/100 (SD=13.4) pre-operatively, 58.2/100 (SD=17.6) at 6-months, 71.8/100 (SD=18.1) at 12-months, and 77.4/100 (SD=19.2) at 24-months post-operative. Functional tests assessing operative to non-operative limb performance demonstrated that patients were continuing to improve up to the 24-month mark, with limb symmetry indices ranging from 96.6–103.1 for the single-leg hop tests. Spearman's correlation coefficient demonstrated a significant relationship between the presence of ACL graft laxity and ACL-QOL score at 12- and 24-months post-operative (p < 0 .05). Functional performance on the single leg balance and single-leg hop tests demonstrated significant correlations to the 6-, 12- and 24-month ACL-QOL scores (p < 0 .05). There was no statistically significant correlation between the functional testing results and the presence of ACL graft laxity.

This study demonstrated that up to 20.6% of patients had clinically measurable graft laxity 2-years after ACLR. In this cohort, patients with graft laxity demonstrated lower ACL-QOL scores, but did not demonstrate lower functional testing performance. Patient-reported ACL-QOL scores improved significantly at each time point following ACLR, and functional performance continued to improve up to 2-years after surgery. The ACL-QOL score was strongly correlated to the patient's ability to perform single-limb functional tests, indicating that the ACL-QOL score accurately predicted level of function.

J. Fairley A. S.E. Younger M. Penner A. Veljkovic K. Wing

A significant portion of ankle arthroplasty and ankle arthrodesis procedures performed in British Columbia are funded by the public medical services plan (MSP). However, some patients are treated privately through self-pay or by the workers compensation board (WCB), with the latter two groups being more likely to receive treatment sooner. The potential effect of payer on patient-reported outcomes and reoperation rates has not been previously explored.

A retrospective chart review was performed using data from the Canadian Orthopaedic Foot and Ankle Society Prospective Ankle Reconstruction Database. N=443 patients (393 MSP, 26 self-pay, 24 WCB), treated with total ankle replacement or ankle arthrodesis by three subspecialty-trained surgeons in Vancouver from 1999–2003, were analyzed. Outcomes were compared, by payer, preoperatively and at long-term follow-up (6.3 years, range 2–14 years). Function was assessed using the Ankle Osteoarthritis Scale (AOS) Total score (primary outcome) and the AOS Pain and Difficulty subscores. Expectation and satisfaction with symptoms was assessed using the Musculoskeletal Outcomes Data Evaluation and Management Scale, and physical and emotional quality of life was assessed using the Short Form-36 (SF-36) Health Survey in terms of the mental component summary (MCS) and physical component summary (PCS). Swelling and reoperation rates were also compared.

AOS Total score was not significantly different between payers. WCB patients had significantly worse preoperative AOS Difficulty scores (73, 95%CI 65–80) compared to MSP (65, CI 63–67) and self-pay patients (56, CI 49–63)(p < 0 .008). Their SF-36 MCS scores were also significantly worse pre- and postoperatively (WCB: 43, CI 38–49, 45, CI 40–50, MSP: 51, CI 50–52, 51, CI 50–52, self-pay: 51, CI 46–56, 54, CI 49–58)(p < 0 .03). AOS Pain scores and SF-36 PCS scores were not different. Pre- and postoperatively, MSP patients reported more satisfaction with symptoms (1.31, CI 1.24–1.38, 3.21, CI 3.07–3.35), compared to WCB (1.13, CI 0.84–1.41, 2.83, CI 2.26–3.41) and self-pay patients (1.19, CI 0.91–1.47, 2.88, CI 2.33–3.44). Preoperatively, WCB patients had the lowest expectations (76, CI 69–84), the worst AOS Total (64, CI 57–71) and SF-36 scores (MCS 43, CI 38–49, PCS 28, CI, 25–32), and the most swelling (3.5, CI 3.1–4). Conversely, self-pay patients had the highest preoperative expectations (88, CI 81–95), the best AOS Total (53, CI 46–60) and SF-36 scores (MCS 51, CI 46–56, PCS: 34, CI 30–37) and the least swelling (3, CI 2.6–3.4). Postoperatively, WCB and self-pay patients had lower expectations met (35, CI 23–47 and 40, CI 28–51) and worse AOS Total scores (36, CI 27–45 and 35, 26–43), compared to MSP patients (Expectations: 29, CI 26–32, AOS Total: 31, CI 29–33). Reoperation rates were similar among groups.

WCB patients had significantly more difficulty with symptoms prior to surgery and worse SF-36 MCS scores pre- and postoperatively. The preoperative expectations of WCB patients were lowest, while those of self-pay patients were highest. Both groups had lower expectations met postoperatively.

M. Neufeld B. A. Masri

A large proportion of wait times for primary total knee (TKA) and hip (THA) arthroplasty is the time from primary care referral to surgical consultation. To our knowledge, no study has investigated whether a referral Oxford Knee or Hip Score (OKHS) could be used to triage non-surgical referrals appropriately. The primary purpose of the current study was to determine if a referral OKHS has the predictive ability to discriminate when a knee or hip referral will be deemed conservative as compared to surgical by the surgeon during their first consultation, and to identify an OKHS cut-off point that accurately predicts when a primary TKA or THA referral will be deemed conservative.

We retrospectively reviewed all consecutive primary TKA and THA consultations from a single surgeon's tertiary, high volume practice over a three-year period. Patients with a pre-consultation OKHS, BMI < 4 1, and no absolute contraindication to TJR were included. Consultation knees/hips were categorized into two groups based on surgeon's decision, those that were offered TJR during their first consolation (surgical) versus those that were not (conservative). Baseline demographic data and OKHS were abstracted. Variables of interest were compared between cohorts using the exact chi-square test and Wilcoxon rank-sum test. Spearman's rank correlation coefficients were used to measure association between pre-consult OKHS and the surgeon's decision. A receiver operator characteristic (ROC) curve analysis was used to calculate the area under the curve (AUC) and to identify a cut-off point for the pre-operative OKHS that identified whether or not a referral was deemed conservative. TKA and THA referrals were analyzed separately.

The study included 1,436 knees (1,016 patients) with a median OKS of 25 (IQR 19–32) and 478 hips (388 patients) with a median OHS of 22 (IQR 16–29). Median pre-consultation OKHS demonstrated clinically and statistically significant differences between the surgical versus conservative cohorts (p 32 (sensitivity=0.997, NPV=0.992) and for hips is OHS >34 (sensitivity=0.997 NPV=0.978). ROC analysis identified severable potential lower OKHS thresholds, depending on weight of prioritization of sensitivity, specificity, and NPV.

Referral OKS and OHS demonstrate good ability to discriminate when a primary TKA or THA referral will be deemed non-surgical versus surgical at their first consultation in a single surgeon's practice. Multiple potential effective OKHS thresholds can be applied as a tool to decrease wait times for primary joint arthroplasty. However, a cost analysis would aid in identifying the optimal cut-off score, and these findings need to be externally validated before they can be broadly applied.

E. Schaeffer J. Bone W. Sankar T. Matheney K. Mulpuri

Avascular necrosis (AVN) of the femoral head is a potentially devastating complication of treatment for developmental dysplasia of the hip (DDH). AVN most commonly occurs following operative management by closed (CR) or open reduction (OR). This occurrence has frequently been examined in single centre, retrospective studies, however, little high-level evidence exists to provide insight on potential risk factors. The purpose of this observational, prospective multi-centre study was to identify predictors of AVN following operatively-managed DDH.

A multi-centre, prospective database of infants diagnosed with DDH from 0–18 months was analyzed for patients treated by CR and/or OR. At minimum one year follow-up, the incidence of AVN (Salter criteria) was determined from AP pelvis radiographs via blinded assessment and consensus discussion between three senior paediatric orthopaedic surgeons. Patient demographics, clinical exam findings and radiographic data were assessed for potential predictors of AVN.

A total of 139 hips in 125 patients (102 female, 23 male) underwent CR/OR at a median age of 10.4 months (range 0.7–27.9). AVN was identified in 37 cases (26.6% incidence) at a median 23 months post-surgery. Univariate logistic regression analysis comparing AVN and no AVN groups identified sex, age at diagnosis, age at surgery, pre-surgery IHDI grade and time between diagnosis and surgery as potential predictive factors. Specifically, male sex (OR 2.21 [0.87,5.72]), IHDI grade IV, and older age at diagnosis (7.4 vs. 9.5 months) and surgery (10.2 vs. 13.6 months) were associated with development of AVN. Likewise, increased time between diagnosis and surgery (2.9 vs. 5.5 months) was also associated with a higher incidence. No association was found with surgery type (CR vs. OR), pre-surgery acetabular index or surgical hip.

Development of AVN occurred in 26.6% of hips undergoing CR or OR at a median 23 months post-surgery. Male sex, older age at diagnosis and surgery, dislocation severity and increased time between diagnosis and surgery were associated with AVN. Longer-term follow-up and larger numbers will be required to confirm these findings. Early outcomes from this prospective patient cohort suggest that AVN is an important complication of operative management for DDH, and appears to occur at a comparable rate whether the reduction is performed open or closed. Male patients may be more susceptible to developing AVN and merits further exploration. Potential predictive factors of older age and length of time between diagnosis and surgery emphasize the importance of early detection and treatment to minimize complications and optimize outcomes.

E. Schaeffer S. Miller M. Juricic K. Mulpuri P. Steinbok J. Bone

Children with cerebral palsy (CP) have an increased risk of progressive hip displacement. While the cause of hip displacement remains unclear, spasticity and muscle imbalance around the hip are felt to be a major factor. There is strong evidence demonstrating that a selective dorsal rhizotomy (SDR) reduces spasticity. However, the impact of this decreased spasticity on hip displacement is unknown. Past studies, which are small and lack long-term follow-up, do not provide a clear indication of the effect of SDR on hip displacement. The purpose of this study was to determine the influence of SDR on hip displacement in children with CP a minimum of five years post-SDR.

A retrospective chart review was completed. Participants were selected from a consecutive series of children who had an SDR before January 1, 2013 at one tertiary care facility to ensure a minimum five year follow-up. Pre-operative and minimum five year post-SDR AP pelvis radiographs were required for inclusion. Hip displacement was evaluated using change in MP between radiographs completed pre-SDR and minimum five years post-SDR, or until orthopaedic hip surgery.

In total, 77 participants (45 males, 32 females) at GMFCS levels of I (1), II (11), III (22), IV (35) and V (8) were included in the review. Mean age at time of SDR was 5 years (2.8– 11.6yrs). Pre-SDR mean MP of the 154 hips was 29% (0–100%). Post-SDR, 67 (43.5%) hips in 35 children had soft tissue, reconstructive, or salvage hip procedures at an average of 4.9 years (0.5–13.8yrs) post-SDR and an average MP of 46% (11–100%). In addition, seven hips (5%) had a MP ≥ 40% (40–100%) at most recent radiographic review that averaged 11 years (5.6–18.6yrs). Overall, the total number of subjects with hip displacement measuring MP >40% or who had a surgical hip intervention, by GMFCS level, was: 0 (0%) at level I, 0 (0%) at level II, 20 (45%) at level III, 22 (59%) at level IV, and 5 (81%) at level V.

The incidence of hip displacement in children with CP post-SDR did not substantially differ from the overall incidence reported in the literature when evaluated by GMFCS level. This study is the largest long-term follow-up study investigating the effect of hip displacement post-SDR. Results suggest that SDR does not impact hip displacement in CP, however, further prospective study will be required to strengthen the evidence in this regard.

C. Schemitsch A. Nauth J. Chahal P. Henry A. Davis D. Da Costa L. Nowak

Rotator cuff injuries represent a significant burden to the health care system, affecting more than 30% of the population over the age of sixty. Despite the advanced surgical techniques that are available, poor results are sometimes seen in a subset of patients receiving surgical treatment for their rotator cuff disease. The reasons for this failure of treatment remain unclear, particularly if the surgery was ‘technically’ successful. An increasing body of evidence has demonstrated a strong correlation between pre-operative psychological factors and functional outcome following several orthopaedic procedures. This association, however, has not been fully demonstrated or effectively investigated in the context of rotator cuff treatment. The main objective for this study was to conduct a systematic review to determine the impact of psychosocial factors on the outcome of treatment in patients with rotator cuff disease.

A systematic search was conducted of Medline, CINAHL, and PsychInfo databases for articles published from database inception until September 2018. The titles and abstracts were screened for all of the studies obtained from the initial search. Inclusion and exclusion criteria were applied, and a full text review was conducted on those studies meeting the eligibility criteria.

A total of 1252 studies were identified. Following removal of duplicates and application of the inclusion and exclusion criteria, 46 studies underwent a full-text review. Ten studies were included in the final analysis. A total of 1,206 patients, with a mean follow-up of 13 months, were included. Three studies examined patient expectations prior to treatment. All three found that higher expectations prior to treatment led to a significantly improved outcome following both operative and non-operative treatment.

Three studies assessed the association between pre-operative general psychological measures and post-operative pain and function. All three studies found patients with worse pre-operative general psychological scores demonstrated increased post-operative pain. Two of the studies also found a negative association with post-operative function, while one of the studies found no association with post-operative function. Three studies assessed the impact of pre-operative anxiety and depression on outcomes following surgical treatment of rotator cuff disease. Only one of the studies found a negative association with post-operative pain and function. The remaining two studies found no association between anxiety or depression and any outcomes following surgery. Finally, one study examined the impact of general distress on outcomes following the surgical treatment of rotator cuff disease and found no association with post-operative levels of pain or function.

The results of this systematic review indicate that there is somewhat conflicting and contradictory evidence within the literature. Overall, however, there does appear to be an association between pre-operative psychological factors and post-operative function and pain, in that higher levels of pre-operative psychological dysfunction are predictive of poorer function and increased pain following the treatment of rotator cuff disease.

M. Beausejour S. Parent P. Dallaire F. Thibeault R. El-Hawary J. Sanders B. Yaszay B. Akbarnia P. Tohme M. Roy-Beaudry

This study addresses a crucial gap in the knowledge of normative spinal growth in children. The objective of this study is to provide detailed and accurate 3D reference values for global and segmental spinal dimensions in healthy children under the age of 11.

Radiographic spine examinations of healthy children conducted to rule out scoliosis were reviewed in four scoliosis referral centers in North America. All consecutive children aged three to eleven years old with EOS biplanar good quality x-rays, but without diagnosed growth-affecting pathologies, were included. Postero-Anterior and Lateral calibrated x-rays were used for spine 3D reconstruction and computation of vertebral body height and spine length. Median and interquartile range were calculated from cross-sectional data. Smooth centiles growth curves for 3D True Spinal Length (3DTSL) between T1 and S1, as well as for mid-vertebral heights of T5, T12 and L3, where fit and calibrated from data using the Lambda-Mu-Sigma method (GAMLSS package for R). This method automatically selects the best performing distribution from a familly of choices. Tables of centiles were then predicted from the computed models for selected ages.

A total of 638 full spine examinations from asymptomatic patients were reconstructed in 3D, 397 in girls and 241 in boys. Medians and interquartile ranges were calculated for 3DTSL (T1-S1): 285 (24) mm, 314 (26) mm and 349 (31) mm, and for selected vertebral heights T5: 10 (1) mm, 11 (1) mm and 12 (1) mm, T12: 13 (2) mm, 14 (1) mm and 16 (2) mm, and L3: 14 (1) mm, 16 (2) mm and 18 (2) mm, respectively for the 3–6, 6–8 and 8–11 age groups. Centile curves ready for clinical use of the 3DTSL (T1-S1) and of the vertebral heights of T5, T12 and L3 as a function of age were derived for the 5, 10, 25, 50, 75, 90 and 95th centiles. In general, boys presented linear relationships between spinal dimensions and age, and girls presented more diverging trends with increased variance for older ages. Accordingly curves for boys follow the Normal distribution whereas those for girls follow the original Box-Cox-Cole-Green distribution. Model diagnostic tests (normally distributed residuals, adequate wormplots and |Z statistics| < 2) confirmed adequacy of the models and the absence of significant misfit.

Accurate reference values were derived for spinal dimensions in healthy children. Spinal dimension charts showed that the spinal lengths and vertebral heights changed relatively constantly across the age groups closely resembling WHO total body height charts. The reference values will help physicians better assess their patients' growth potential. It could also be used to predict expected spinal dimensions at maturity or changes in pathologic conditions as well as to assess the impact of growth friendly interventions in the correction of spinal deformities.

M. Hartwell P. Nelson D. Johnson R. Nicolay R. Christian R. Selley V. Tjong M. Terry

Recent studies have described safe outcomes for short-stays in the hospital after total shoulder arthroplasty. The purpose of this study is to identify pre-operative and operative risk factors for hospital admissions exceeding 24 hours.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried from 2006 to 2016 for the current procedural terminology (CPT) billing code related to total shoulder arthroplasty. Patients were then grouped as either having a length of stay (LOS) equal to or less than 24 hours or greater than 24 hours. Patients admitted to the hospital prior to the day of surgery were excluded. Patient demographics, co-morbidities, and operative time were then analyzed as risk factors for a hospital stay exceeding 24 hours. Pre-operative co-morbidities included body mass index (BMI), diabetes, smoking, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), hypertension, dialysis, chronic steroid or immunosuppressant use, bleeding disorders, and American Society of Anesthesiologists (ASA) Classification. Univariate and multivariate analyses were then performed to identify risk factors associated with 30-day readmission.

14,339 patients met inclusion criteria and 6,507 (45.3%) had a hospital LOS less than or equal to 24 hours. The mean length of hospitalization was 1.95 ± 1.88 days, the average age was 69 ± 9.7 years old, and 56.9% of the patients were female. Following a risk adjusted multivariate analysis, increasing age (odds ratio [OR], 1.03, 95% confidence interval [CI], 1.02–1.03), ASA classification (OR, 1.50, 95% CI, 1.41–1.60), diabetes (OR, 1.69, 95% CI, 1.43–1.99), COPD (OR, 1.35, 95% CI, 1.16–1.57), CHF (OR, 2.67, 95% CI, 1.34–5.33), dialysis (OR, 2.47, 95% CI, 1.28, 4.77), history of a bleeding disorder (OR, 1.50, 95% CI, 1.20–1.88), or increasing operative time (OR, 1.01, 95% CI, 1.01–1.01) were identified as independent risk factors for hospital lengths of stay exceeding 24 hours. Male gender was identified as a protective factor for prolonged hospitalization (OR, 0.50, 95% CI, 0.46–0.53).

This study identifies patient demographics, co-morbidities, and operative-relative risk factors that are associated with increased risk for a prolonged hospitalization following total shoulder arthroplasty. Female gender, increasing age, ASA classification, operative time, or a history of diabetes, COPD, CHF, or history of a bleeding disorder are risk factors hospitalizations exceeding 24 hours.

M. Wong R. Buckley P. Duffy R. Korley R. Martin T. Harrison D. W. Sanders P. Schneider C. Wiens

The syndesmosis ligament complex stabilizes the distal tibiofibular joint, while allowing for the subtle fibular motion that is essential for ankle congruity. Flexible fixation with anatomic syndesmosis reduction results in substantial improvements in functional outcomes. New dynamic CT technology allows real-time imaging, as the ankle moves through a range of motion. The aim of this study was to determine if dynamic CT analysis is a feasible method for evaluating syndesmosis reduction and motion following static and flexible syndesmosis fixation.

This is a subgroup analysis of a larger multicenter randomized clinical trial, in which patients with AO 44-C injuries were randomized to either Tightrope (one knotless Tightrope, Group T) or screw fixation (two 3.5-mm cortical screws, Group S). Surgical techniques and rehabilitation were standardized. Bilateral ankle CT scans were performed at one year post-injury, while patients moved from maximal dorsiflexion (DF) to maximal plantar flexion (PF). Three measurements were taken at one cm proximal to the ankle joint line in maximal DF and maximal PF: anterior, midpoint, and posterior tibiofibular distances. T-tests compared Group T and Group S, and injured and uninjured ankles in each group.

Fifteen patients (six Group T [three male], nine Group S [eight male]) were included. There was no difference for mean age (T = 42.8 ± 14.1 years, S = 37 ± 12.6, P = 0.4) or time between injury and CT scan (T = 13 ± 1.8 months, S = 13.2 ± 1.8, P = 0.8). Of note in Group S, seven of nine patients had at least one broken screw and one additional patient had screws removed by the time of their dynamic CT. There was no significant difference between treatment groups for tibiofibular distance measurements in maximal PF or DF. Group T showed no significant difference between the injured and uninjured side for tibiofibular measurements in maximal PF and DF, suggesting anatomic reduction. For Group S, however, there was a significantly larger distance for all three measurements at maximal PF compared to the uninjured ankle (all P < 0 .05).

In all but one Group S patient, screws were broken or removed prior to their dynamic CT, allowing possible increased syndesmotic motion, similar to Group T. Despite this, dynamic CT analysis detected increased tibiofibular distance in Group S as ankles moved into maximal PF when compared with the uninjured ankle. Given the importance of anatomic syndesmosis reduction, dynamic ankle CT technology may provide valuable physiologic information warranting further investigation.

S. St George A. Veljkovic H. S. Hamedany K. Wing M. Penner P. Salat A. S. E. Younger

Classification systems for the reporting of surgical complications have been developed and adapted for many surgical subspecialties. The purpose of this systematic review was to examine the variability and frequency of reporting terms used to describe complications in ankle fracture fixation. We hypothesized that the terminology used would be highly variable and inconsistent, corroborating previous results that have suggested a need for standardized reporting terminology in orthopaedics.

Ankle fracture outcome studies meeting predetermined inclusion and exclusion criteria were selected for analysis by two independent observers. Terms used to define adverse events were identified and recorded. If a difference occurred between the two observers, a third observer was enlisted. Results of both observers were compared. All terms were then compiled and assessed for variability and frequency of use throughout the studies involved. Reporting terminology was subsequently grouped into 10 categories.

In the 48 studies analyzed, 301 unique terms were utilized to describe adverse events. Of these terms, 74.4% (224/301) were found in a single study each. Only one term, “infection”, was present in 50% of studies, and only 19 of 301 terms (6.3%) were used in at least 10% of papers. The category that was most frequently reported was infection, with 89.6% of studies reporting on this type of adverse event using 25 distinct terms. Other categories were “wound healing complications” (72.9% of papers, 38 terms), “bone/joint complications” (66.7% of papers, 35 terms), “hardware/implant complications” (56.3% of papers, 47 terms), “revision” (56.3% of papers, 35 terms), “cartilage/soft tissue injuries” (45.8% of papers, 31 terms), “reduction/alignment issues” (45.8% of papers, 29 terms),“medical complications” (43.8% of papers, 32 terms), “pain” (29.2% of papers, 16 terms) and “other complications” (20.8% of papers, 13 terms). There was a 78.6% interobserver agreement in the identification of adverse terms across the 48 studies included.

The reporting terminology utilized to describe adverse events in ankle fracture fixation was found to be highly variable and inconsistent. This variability prevents accurate reporting of adverse events and makes the analysis of potential outcomes difficult. The development of standardized reporting terminology in orthopaedics would be instrumental in addressing these challenges and allow for more accurate and consistent outcomes reporting.

R. Y. Rampersaud M. Canizares J. D. Power A. Perruccio R. Gandhi J. R. Davey K. Syed S. J. Lewis N. Mahomed

Patient satisfaction is an important measure of patient-centered outcomes and physician performance. Given the continued growth of the population undergoing surgical intervention for osteoarthritis (OA), and the concomitant growth in the associated direct costs, understanding what factors drive satisfaction in this population is critical. A potentially important driver not previously considered is satisfaction with pre-surgical consultation. We investigated the influence of pre-surgical consultation satisfaction on overall satisfaction following surgery for OA.

Study data are from 1263 patients who underwent surgery for hip (n=480), knee (n=597), and spine (n=186) OA at a large teaching hospital in Toronto, Canada. Before surgery, patient-reported satisfaction with information received and degree of input in decision-making during the pre-surgical consultation was assessed, along with expectations of surgery (regarding pain, activity limitation, expected time to full recovery and likelihood of complete success). Pre- and post-surgery (6 weeks, and 3, 6, and 12 months) patients reported their average pain level in the past week (0–10, 10 is worst). At each follow-up time-point, two pain variables were defined, pain improvement (minimal clinically important difference from baseline ≥2 points) and ‘acceptable’ pain (pain score ≤ 3). Patients also completed a question on satisfaction with the results of the surgery (very dissatisfied/dissatisfied/somewhat satisfied/very satisfied) at each follow-up time point. We used multilevel ordinal logistic regression to examine the influence of pre-surgery satisfaction with consultation on the trajectory of satisfaction over the year of recovery controlling for expectations of surgery, pain improvement, acceptable pain, socio-demographic factors (age, sex, and education), body mass index, comorbidity, and depressive symptoms (Hospital Anxiety and Depression Scale).

Mean age of the sample was 65.5 years, and over half (54.3%) were women. Overall, 74% and 78.9% of patients were satisfied with the information received and with the decision-making in the pre-surgical consultation, respectively, no significant differences were found by surgical joint (p=0.22). Post-surgery, levels of satisfaction varied very little over time (6 weeks: 92.5% were satisfied and 66.4% were very satisfied, 1 year: 91.1% were satisfied and 65.6% were very satisfied). Results from a model including time, surgical joint, satisfaction with consultation and control factors indicated that being satisfied with the information received in the pre-surgical consultation was associated with higher odds of being more satisfied after surgery (OR: 1.2, 95% CI: 1–1.4). Additionally, spine and knee patients were more likely to be dissatisfied than hip patients (OR: 3.2, 95% CI: 2.1–4.9 and OR: 2.5, 95% CI: 1.8–3.4 for spine and knee patients respectively). Achieving pain improvement (OR: 1.7, 95% CI: 1.3–2.4) and acceptable pain (OR: 2.5, 95% CI: 1.6–3.9) were both significantly associated with greater satisfaction. Pre-operative expectations were not significantly associated with post-surgery satisfaction.

Findings highlight the important role of pre-surgery physician-patient communication and information on post-surgery satisfaction. This points to the need to ensure organizational provisions that foster supportive and interactive relationships between surgeons and their patients to improve patients' satisfaction. Findings also highlight that early post-recovery period (i.e. <= 3 months) as a key driver of longer-term satisfaction.

P. Beaulé G. Melkus K. Rakhra G. Wilkin

Developmental dysplasia of the hip (DDH) is a common risk factor of early osteoarthritis (OA), with insufficient coverage of the femoral head by the acetabulum which leads to excessive cartilage stresses in the hip joint. Knowledge of the molecular health of cartilage using MRI may diagnose and stage chondral disease, but more importantly allows for treatment stratification and prognostication. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a validated MRI technique for detecting early loss of proteoglycan (PG). However, it requires an injection of contrast agent and exercise prior to the scan. MRI techniques such as T1ρ and T2 mapping have also been shown to be sensitive to early biochemical changes in cartilage but can be performed without any contrast injection. In this study we evaluate three quantitative MR techniques (dGEMRIC, T1ρ and T2 mapping) in patients with DDH. Our hypothesis is that both T1ρ and T2 correlate with dGEMRIC, and thus may be effective non-contrast based techniques for biochemical cartilage mapping in DDH hips.

Seven informed and consented patients (mean age: 31.1 years) with DDH were enrolled in this IRB approved MRI study before surgery. DDH was defined as a lateral center-edge angle under 25º and acetabular index >13º on the plain x-ray. All subjects underwent two successive MRI sessions at 3T: In the first cartilage T1ρ and T2 mapping were performed. After leaving the scanner the subjects were injected with 0.4ml/kg Dotarem (i.v.), walked for 15min and rested for 25min before returning into the MRI. dGEMRIC (T1post) mapping was initiated approximately 45min after the injection. Image post-processing, registration and cartilage segmentation was performed with Matlab. The joint was subdivided into anterior and posterior regions in the sagittal plane and into lateral, intermediate and medial zones in the transverse plane, resulting in six region of interest (ROIs): antero-lateral, antero-intermediate, antero-medial, postero-lateral, postero-intermediate and postero-medial. The correlation between the dGEMRIC and T1ρ and dGEMRIC and T2 were evaluated using Spearman's Rho and tested for significance.

The analysis of all six cartilage ROIs for all subjects resulted in a significant (p < 0 .001) negative correlation (Rho = −0.50) between the dGEMRIC index (T1post) and the T1ρ relaxation time. The dGEMRIC index and T2 correlated positive (Rho = 0.55) and significant (p < 0 .001).

Although this pilot study has a small sample size a negative correlation between dGEMRIC and T1ρ was found in patients with DDH. Both methods are known to probe the PG content of cartilage, where a decreased PG content leads to lower dGEMRIC index and an increased T1ρ value. The correlation coefficient was moderate, but significant, which shows that T1ρ mapping as an effective tool to probe the cartilage PG content similar to dGEMRIC. A comparable, but positive correlation was found between dGEMRIC and T2. T2 is sensitive to the cartilage collagen content with a decreased T2 value in degenerated cartilage. In symptomatic DDH, where an onset of OA is assumed, both PG depletion and collagen decay are in progress and can be evaluated using these mapping techniques.

R. Y. Rampersaud J. D. Power A. Perruccio M. Paterson C. Veillette E. Badley N. Mahomed

The objective of this study was to quantify the burden of musculoskeletal disorders (MSDs) on the Ontario health care system. Specifically, we examined the magnitude and costs of MSD-associated ambulatory physician care and hospital service use, considering different physician types (e.g. primary care, rheumatologists, orthopaedic surgeons) and hospital settings (e.g. emergency department (ED), day surgery, inpatient hospitalizations).

Administrative health data were analyzed for fiscal year 2013/14 for adults aged 18+ years (N=10,841,302). Data sources included: Ontario Health Insurance Plan Claims History Database, which captures data on in- and out-patient physician services, Canadian Institute for Health Information (CIHI) Discharge Abstract Database, which records diagnoses and procedures associated with all inpatient hospitalizations, and CIHI National Ambulatory Care Reporting System, which captures data on all emergency department (ED) and day surgery encounters. Services associated with MSDs were identified using the single three digit International Classification of Diseases (ICD) version 9 diagnosis code provided on each physician service claim for outpatient physician visits and the “most responsible” ICD-10 diagnosis code recorded for hospitalizations, ED visits and day surgeries. Patient visit rates and numbers of patients and visits were tabulated according to care setting, patient age and sex, and physician specialty. Direct medical costs were estimated by care setting. Data were examined for all MSDs combined as well as specific diagnostic groupings, including a comprehensive list of both trauma and non-trauma related conditions.

Overall, 3.1 million adult Ontarians (28.5%) made 8 million outpatient physician visits associated with MSDs in 2013/14. These included 5.6 million primary care visits, nearly 15% of all adult primary care visits in the province. MSDs accounted for 560,000, 12.3%, of all adult ED visits. Patient visit rates to the ED for non-trauma spinal conditions were the highest of all MSDs at 1032 per 100,000 population, accounting for 23% of all MSD-related ED visits. Osteoarthritis had the highest rate of inpatient hospitalization of all MSDs at 340 per 100,000 population, accounting for 42% of all MSD-related admissions. Total costs for MSD-related care were $1.6 billion, with 12.6% of costs attributed to primary care, 9.2% to specialist care, 8.6% to ED care, and 61.2% of total costs associated with inpatient hospitalizations. Costs due to ‘arthritis and related conditions’ as a group accounted for 40.1% of total MSD costs ($966 million). Costs due to non-trauma related spinal conditions accounted for 10.5% ($168 million) of total MSD costs. All trauma-related conditions (spine and non-spine combined) were responsible for 39.4% ($627 million) of total MSD costs. MSD-related imaging costs for patients who made physician visits for MSDs were $169 million. Including these costs yields a total of $1.8 billion.

MSDs place a significant and costly burden on the health care system. As the population ages, it will be essential that health system planning takes into account the large and escalating demand for MSD care, both in terms of health human resources planning and the implementation of more clinically and cost effective models of care, to reduce both the individual and population burden.

J. Hurry A. Spurway M. J. Dunbar R. El-Hawary

Radiostereometric analysis (RSA) allows for precise measurement of interbody distances on X-ray images, such as movement between a joint replacement implant and the bone. The low radiation biplanar EOS imager (EOS imaging, France) scans patients in a weight-bearing position, provides calibrated three-dimensional information on bony anatomy, and could limit the radiation during serial RSA studies. Following the ISO-16087 standard, 15 double exams were conducted to determine the RSA precision of total knee arthroplasty (TKA) patients in the EOS imager, compared to the standard instantaneous, cone-beam, uniplanar digital X-ray set-up.

At a mean of 5 years post-surgery, 15 TKA participants (mean 67 years, 12 female, 3 male) were imaged twice in the biplanar imager. To reduce motion during the scan, a support for the foot was added and the scan speed was increased. The voltage was also increased compared to standard settings for better marker visibility over the implant. A small calibration object was included to remove any remaining sway in post-processing.

The 95% confidence interval precision was 0.11, 0.04, and 0.15 mm in the x, y, and z planes, respectively and 0.15, 0.20, and 0.14° in Rx, Ry, and Rz. Two participants had motion artifacts successfully removed during post-processing using the small calibration object.

With faster speeds and stabilization support, this study found an in vivo RSA precision of ≤ 0.15 mm and ≤ 0.20° for TKA exams, which is within published uniplanar values for arthroplasty RSA. The biplanar imager also adds the benefits of weight bearing imaging, 3D alignment measurements, a lower radiation dose, and does not require a reference object due to known system geometry and automatic image registration.

T. Burkhart P. Baha A. Getgood R. Degen

While hip arthroscopy utilization continues to increase, capsular management remains a controversial topic. Therefore the purpose of this research was to investigate the biomechanical effect of capsulotomy and capsular repair techniques on hip joint kinematics in varying combinations of sagittal and coronal joint positions.

Eight fresh-frozen hemipelvises (4 left, 6 male) were dissected of all overlying soft tissue, with the exception of the hip joint capsule. The femur was potted and attached to a load cell, while the pelvis was secured to a custom-designed fixture allowing static alteration of the flexion/extension arc. Optotrak markers were rigidly attached to the femur and pelvis to track motion of the femoral head with respect to the acetabulum.

Following specimen preparation, seven conditions were tested: i) intact, ii) after portal placement (anterolateral and mid-anterior), iii) interportal capsulotomy (IPC) [35 mm in length], iv) IPC repair, v)T-capsulotomy [15 mm longitudinal incision], vi) partial T-repair (vertical limb), vii) full T-repair. All conditions were tested in 15° of extension (−15˚), 0°, 30°, 60° and 90° of flexion. Additionally, all flexion angles were tested in neutral, as well as maximum abduction and adduction, resulting in 15 testing positions. 3Nm internal and external rotation moments were manually applied to the femur via the load cell at each position. Rotational range of motion and joint kinematics were recorded.

IPC and T-capsulotomies increased rotational ROM and mediolateral (ML) joint translation in several different joint configurations, most notably from 0–30˚ in neutral abduction/adduction. Complete capsular repair restored near native joint kinematics, with no significant differences between any complete capsular repair groups and the intact state, regardless of joint position. An unrepaired IPC resulted in increased rotational ROM, but no other adverse translational kinematics. However, an unrepaired or partially repaired T-capsulotomy resulted in increased rotational ROM and ML translation.

The results of this study show that complete capsular repair following interportal or T-capsulotomy adequately restores rotational ROM and joint translation to near intact levels. Where feasible, complete capsular closure should be performed, especially following T-capsulotomy. However, further clinical evaluation is required to determine if adverse kinematics of an unrepaired capsule are associated with patient reported outcomes.

S. Larrive P. Larouche T. Jelic R. Rodger J. Leiter P. B. MacDonald

Musculoskeletal ultrasound (MSK-US) can have many uses for orthopaedic surgeons, such as assisting in clinical diagnosis for muscle, tendon and ligament injuries, providing direct guidance for joint injections, or assessing the adequacy of a reduction in the emergency department. However, proficiency in sonography is not a requirement for Royal College certification, and orthopaedic trainees are rarely exposed to this modality. The purpose of this project was to assess the usefulness in clinical education of a newly implemented MSK-US course in an orthopaedic surgery program.

A MSK-US course for orthopaedic surgery residents was developed by an interdisciplinary team involving a paediatric orthopaedic surgeon, an emergency physician with a fellowship in point-of-care ultrasonography, and an orthopaedic surgery resident. Online videos were created to be viewed by residents prior to a half-day long practical course. The online portion covered the basics of ultrasonography, as well as the normal and abnormal appearance of musculoskeletal structures, while the practical portion applied those principles to the examination, injection, and aspiration of joints, and ultrasound-guided fracture reduction. An online survey covering the level of training of the resident and their previous use of ultrasound (total hours) was filled by the participants prior to the course. Resident's knowledge acquisition was measured with a written pre-course, same-day post-course and six-month follow-up tests. Residents were also scored on a practical shoulder examination immediately after the course and at six-month follow-up. An online survey was also sent to evaluate residents' satisfaction with different aspects of the course (NAS). Change in test scores were calculated using an ANOVA and a Wilcoxon signed-rank test.

Ten orthopaedic surgery residents underwent the MSK-US curriculum. Pre-course interest to MSK-US was moderate (65%) and prior exposure was low (1.5 hours mean total experience). MSK-US has been previously mostly observed in the emergency department and sports orthopaedic clinic. Satisfaction with the online curriculum, hands-on practice session and general quality of the course were high (8.78, 8.70 and 8.60/10 respectively). Written test scores improved significantly from 50.7 ± 17% to 84 ± 10.7% immediately after the course (p < 0 .001) and suffered no significant drop at six months (score 75 ± 8.7%, p=0.303). Average post-course practical exam score was 78.8 ± 3.1% and decreased to 66.2 ± 11.3% at six months (p=0.012). Residents significantly improved their subjective comfort level with all aspects of ultrasound use at six months (p=0.007–0.018) but did not significantly increase clinical usage frequency.

A MSK-US curriculum was successfully developed and implemented using an interdisciplinary approach. The course was rated high quality and succeeded in improving the residents' knowledge, skills, and comfort with MSK-US. This improvement was maintained at six months on the written test, but did not result in higher frequency of use by the residents.

A. Faizan J. Zhang L. Scholl

Iliopsoas tendonitis after total hip arthroplasty (THA) can be a considerable cause of pain and patient dissatisfaction. The optimal cup position to avoid iliopsoas tendonitis has not been clearly established. Implant designs have also been developed with an anterior recess to avoid iliopsoas impingement. The purpose of this cadaveric study was to determine the effect of cup position and implant design on iliopsoas impingement.

Bilateral THA was performed on three fresh frozen cadavers using oversized (jumbo) offset head center revision acetabular cups with an anterior recess (60, 62 and 66 mm diameter) and tapered wedge primary stems through a posterior approach. A 2mm diameter flexible stainless steel cable was inserted into the psoas tendon sheath between the muscle and the surrounding membrane to identify the location of the psoas muscle radiographically. CT scans of each cadaver were imported in an imaging software. The acetabular shells, cables as well as pelvis were segmented to create separate solid models of each. The offset head center shell was virtually replaced with an equivalent diameter hemispherical shell by overlaying the outer shell surfaces of both designs and keeping the faces of shells parallel. The shortest distance between each shell and cable was measured. To determine the influence of cup inclination and anteversion on psoas impingement, we virtually varied the inclination (30°/40°/50°) and anteversion (10°/20°/30°) angles for both shell designs.

The CT analysis revealed that the original orientation (inclination/anteversion) of the shells implanted in 3 cadavers were as follows: Left1: 44.7°/23.3°, Right1: 41.7°/33.8°, Left2: 40/17, Right2: 31.7/23.5, Left3: 33/2908, Right3: 46.7/6.3. For the offset center shells, the shell to cable distance in all the above cases were positive indicating that there was clearance between the shells and psoas. For the hemispherical shells, in 3 out of 6 cases, the distance was negative indicating impingement of psoas. With the virtual implantation of both shell designs at orientations 40°/10°, 40°/20°, 40°/30° we found that greater anteversion helped decrease psoas impingement in both shell designs. When we analyzed the influence of inclination angle on psoas impingement by comparing wire distances for three orientations (30°/20°, 40°/20°, 50°/20°), we found that the effect was less pronounced. Further analysis comparing the offset head center shell to the conventional hemispherical shell revealed that the offset design was favored (greater clearance between the shell and the wire) in 17 out of 18 cases when the effect of anteversion was considered and in 15 out of 18 cases when the effect of inclinations was considered.

Our results indicate that psoas impingement is related to both cup position and implant geometry. For an oversized jumbo cup, psoas impingement is reduced by greater anteversion while cup inclination has little effect. An offset head center cup with an anterior recess was effective in reducing psoas impingement in comparison to a conventional hemispherical geometry. In conclusion, adequate anteversion is important to avoid psoas impingement with jumbo acetabular shells and an implant with an anterior recess may further mitigate the risk of psoas impingement.

I. K. Y. Lo A. Bois J. LeBlanc J. Woodmass C. Kwong E. Gusnowski A. Lo

Rotator cuff disease encompasses a spectrum from partial to full thickness tears. Despite being 2–3 times more common than full–thickness tears, effective non-operative treatment for partial thickness tears has remained elusive. Platelet enriched plasma (PRP) has been proposed to enhance rotator cuff healing by enhancing the natural healing cascade. However, its utility in rotator cuff disease remains controversial. The purpose of this study was to compare the patient reported outcomes between PRP and corticosteroid injection in patients with symptomatic partial thickness tears.

This double blind randomized controlled trial enrolled patients with symptomatic, partial thickness rotator cuff tears or rotator cuff tendinopathy proven on ultrasound or MRI. Patients were randomized to either corticosteroid or PRP ultrasound-guided injection of the affected shoulder. Patients completed patient reported outcomes at 6 weeks and 12 weeks. The primary outcome was Visual Analog Scale (VAS) pain scores. Secondary outcomes included the Western Ontario Rotator Cuff (WORC) index, American Shoulder and Elbow Surgeons (ASES) score, and failure of non-operative management as determined by consent for surgery or progression to operative intervention.

Ninety-nine patients were enrolled in the study with equal demographics between the two groups. Taking into account pre-injection scores, patients with PRP injections demonstrated a statistically significant improvement in VAS scores compared to patients receiving corticosteroid injections at 12 weeks (p=0.045) but not at 6 weeks (p=0.704). There was no difference in other outcome measures or progression of the two groups to surgical intervention.

The use of PRP in the management of partial thickness rotator cuff tears demonstrates significant improvement of pain scores at 12 week follow up compared to corticosteroid injections. However, this did not affect the rate of progression to surgical intervention. Continued study is required to determine the utility of PRP in this patient population.

S. M. Colgan E. H. Schemitsch J. Adachi N. Burke M. Hume J. Brown D. McErlain

Fragility fractures associated with osteoporosis (OP) reduce quality of life, increase risk for subsequent fractures, and are a major economic burden. In 2010, Osteoporosis Canada produced clinical practice guidelines on the management of OP patients at risk for fractures (Papaioannou et al. CMAJ 2010). We describe the real-world incidence of primary and subsequent fragility fractures in elderly Canadians in Ontario, Canada in a timespan (2011–2017) following guideline introduction.

This retrospective observational study used de-identified health services administrative data generated from the publicly funded healthcare system in Ontario, Canada from the Institute for Clinical Evaluative Sciences. The study population included individuals ≥66 years of age who were hospitalized with a primary (i.e. index) fragility fracture (identified using ICD-10 codes from hospital admissions, emergency and ambulatory care) occurring between January 1, 2011 and March 31, 2015. All relevant anatomical sites for fragility fractures were examined, including (but not limited to): hip, vertebral, humerus, wrist, radius and ulna, pelvis, and femur. OP treatment in the year prior to fracture and subsequent fracture information were collected until March 31, 2017. Patients with previous fragility fractures over five years prior to the index fracture, and those fractures associated with trauma codes, were excluded.

115,776 patients with an index fracture were included in the analysis. Mean (standard deviation) age at index fracture was 80.4 (8.3) years. In the year prior to index fracture, 32,772 (28.3%) patients received OP treatment. The incidence of index fractures per 1,000 persons (95% confidence interval) from 2011–2015 ranged from 15.16 (14.98–15.35) to 16.32 (16.14–16.51). Of all examined index fracture types, hip fractures occurred in the greatest proportion (27.3%) of patients (Table). The proportion of patients incurring a second fracture of any type ranged from 13.4% (tibia, fibula, knee, or foot index fracture) to 23% (vertebral index fracture). Hip fractures were the most common subsequent fracture type and the proportion of subsequent hip fractures was highest in patients with an index hip fracture (Table). The median (interquartile range [IQR]) time to second fracture ranged from 436 (69–939) days (radius and ulna index fracture) to 640 (297–1,023) days (tibia, fibula, knee, or foot index fracture). The median (IQR) time from second to third fracture ranged from 237 (75–535) days (pelvis index fracture) to 384 (113–608) days (femur index fracture).

This real-world study found that elderly patients in Ontario, Canada incurring a primary fragility fracture from 2011–2015 were at risk for future fractures occurring over shorter periods of time with each subsequent fracture. These observations are consistent with previous reports of imminent fracture risk and the fragility fracture cascade in OP patients (Balasubramanian et al. ASBMR 2016, Toth et al. WCO-IOF-ESCEO 2018). Overall, these data suggest that in elderly patients with an index fragility fracture at any site (with the exception of the radius or ulna), the most likely subsequent fracture will occur at the hip in less than 2 years.

S. McRae G. Matthewson J. Leiter P. B. MacDonald S. Lenschow

The purpose of this study was to quantify tibial tunnel enlargement at 3-, 6- and 12-months post-anterior cruciate ligament reconstruction (ACLR), and evaluate the magnitude of tunnel widening with use of a Poly (L-lactic Acid) interference screw (PLLA (Bioscrew XtraLok, Conmed, New York)) compared to a Poly (L-lactic Acid) + tricalcium phosphate interference screw (PLLA+TCP (GENESYS Matryx screw comprised of microTCP and 96L/4D PLA, Conmed, New York)).

This was a prospective randomized controlled trial with two parallel groups. Eighty unilateral ACL-deficient participants awaiting ACLR surgery were recruited between 2013 and 2017 from the clinic of a sole fellowship trained orthopaedic surgeon. Patients had to be skeletally mature and less than 45 years old, with no concomitant knee ligament injuries requiring surgery, chondromalacia, or previous history of ipsilateral knee joint pathology, surgery or trauma to the knee.

Participants were randomized intra-operatively into either the PLLA or PLLA+TCP tibial interference screw fixation group. Study time points were pre-, 3-, 6-, and 12-months post ACLR. Participants underwent x-rays with a 25 mm calibration ball, IKDC knee assessment, and completed the ACL-Quality of Life score (ACL-QOL) at each visit.

Measurement (mm) of the most proximal and distal extents as well as the widest point of the tibial tunnel were taken using efilm (IBM Watson Health) and were standardized relative to the calibration ball. A contrast inverter was used to determine clear borders based on contrast between normal and drilled bone. In addition, a subjective evaluation of the tunnel was conducted looking for bowing of the borders of the tunnel or change in tunnel shape, categorizing the tunnel as widened or not widened.

Differences between groups at each time point were evaluated using independent t-tests corrected for multiple comparisons. Tunnel width was also compared as a percentage of actual screw size at 12-months post-operative. Categorical data were compared using Fisher's Exact Test. Forty participants were randomized to each group with mean age (SD) of 29.7 (7.6) and 29.8 (9.1), for PLLA and PLLA+TCP, respectively. There were no differences between groups in age, gender or ACL-QOL.

There were no differences found between groups at any time point in either tunnel width measurements or tunnel width as a percentage of actual screw size. The greatest difference between groups was noted in the measurement of the widest point on lateral x-ray view with a mean difference of 11%. Based on subjective evaluation of tunnel shape, three participants had visible widening in the PLLA group, and two in the PLLA+TCP group (p=NS).

No differences in tunnel widening were identified between ACL reconstruction patients using a PLLA interference screw compared to a PLLA+TCP screw for tibial fixation up to 12-months post-operative.

Y. Li C. Stiegelmar M. Funabashi E. Pedersen D. Dillane L. Beaupre

Chronic postoperative pain (CPP) can occur in elective mid/hindfoot and ankle surgery patients. Multimodal pain management has been reported to reduce postoperative pain and opioid use, which may prevent the development of CPP. However, few studies have examined the impact of multimodal pain management strategies on CPP following complex elective mid/hindfoot and ankle surgery. The purpose of this study was to 1) evaluate current pain management strategies and 2) determine current definitions, incidence, and prevalence of CPP after elective mid/hindfoot and ankle surgery.

Three databases (MEDLINE, Embase and Cochrane Library) were manually and electronically searched for English language studies published between 1990 and July 2017. For the first aim, we included comparative studies of adults undergoing elective mid/hindfoot and ankle surgery that investigated pre-, peri- or postoperative pain management. For the second aim, we included observational studies examining CPP definition, incidence, and prevalence. Two reviewers independently screened titles and abstracts, followed by full texts. Conflicts were resolved through discussion with a third reviewer. Reviewers also independently assessed the quality of studies meeting inclusion criteria using the Joanna Briggs Institute Critical Appraisal Checklist.

For the first aim, 1159 studies were identified by the primary search, and seven high quality randomized controlled trials were included. Ankle arthroplasty or fusion and calcaneal osteotomy were the most common procedures performed. The heterogeneity of study interventions, though all regional anesthesia techniques, precluded meta-analysis. Most investigated continuous popliteal, sciatic and/or femoral nerve blockade. Participants were typically followed up to 48 hours postoperatively to examine postoperative pain levels and morphine consumption in hospital. Interventions effective at reducing postoperative pain and/or morphine consumption included inserting popliteal catheters using ultrasound instead of nerve stimulation guidance, perineural dexamethasone, and adding continuous femoral blockade to continuous popliteal blockade. Using more than one analgesic was generally more effective than using a single agent. Only two studies examined longer term pain management. One found no difference in pain levels and opioid consumption at two weeks with perineural or systemic dexamethasone use. The other found that pain with activity was significantly reduced at six months postoperatively with the addition of a femoral catheter infusion to a popliteal catheter infusion. For the second aim, only two studies of the 747 identified were selected. One prospective observational study defined CPP as moderate-to-severe pain at one year after foot and ankle surgery, and reported 21% and 43% of patients as meeting their definition at rest and with activity, respectively. The other study was a systematic review that reported 23–60% of patients experienced residual pain after total ankle arthroplasty.

There is no standardized definition of CPP in this population, and incidence and prevalence are rarely reported and vary largely based on definition. Although regional anesthesia may be effective at reducing in-hospital pain and opioid consumption, evidence is very limited regarding longer-term pain management and associated outcomes following elective mid/hindfoot and ankle surgery.

J. Akindolire S. Ndoja A. Lawendy B. Lanting R. Degen

Closed ankle fractures have been reported to account for 10% off all fractures presenting to the Emergency Department. Many of these injuries require acute surgical management either via direct admission or through defined outpatient surgical pathways. While both methods have been shown to be safe, few studies have examined the cost effectiveness of each clinical scenario. The purpose of this study is to compare cost and resource utilization associated with inpatient and outpatient ankle fracture surgery at a Canadian academic institution.

This is a retrospective chart review of patients who underwent acute ankle fracture surgery at London Health Sciences Centre between 2016 and 2018. Thirty patients who underwent inpatient ankle surgery for closed, isolated ankle fractures at University Hospital were compared to 30 consecutive patients who underwent outpatient ankle surgery for similar fractures at Victoria hospital. Data pertaining to age at time of surgery, sex, BMI, fracture type, operating/recovery room time, and length of hospital stay were collected. All emergency room visits, readmissions and complications within 30 days of surgery were also recorded.

Inpatient and outpatient cohorts were similar with respect to average age (48 vs. 44, P=0.326) and body mass index (29.8 vs. 29.1, P=0.741). There was a greater proportion of patients with an American Society of Anesthesia (ASA) Classification of 3 or greater in the inpatient surgery group (48% vs. 23%). The inpatient group spent an average of 1.2 days in hospital while waiting for surgery and a average of 72 hours in hospital for their entire surgical encounter. The outpatient group spent an average of eight days (at home) waiting for surgery while spending an average of 7.4 hours in hospital during their entire surgical encounter. Outpatient ankle fracture surgery was associated with a cost savings of 35.9% in comparison to inpatient ankle fracture surgery (P < 0 .001). There were no significant differences in the rates of emergency room visits, readmissions, or complications between cohorts.

Preliminary findings suggest that outpatient ankle fracture surgery is appropriate for most patients, requires less hospital resources and is associated with similar rates of readmission and complications as inpatient surgery. An established outpatient surgical pathway may offer significant cost savings in the treatment of the common closed ankle fracture that requires surgical intervention.

W. S. Lian F-S. Wang C. K. Hsieh

Aberrant infrapatellar fat metabolism is a notable feature provoking inflammation and fibrosis in the progression of osteoarthritis (OA). Irisin, a secretory subunit of fibronectin type III domain containing 5 (FNDC5) regulate adipose morphogenesis, energy expenditure, skeletal muscle, and bone metabolism. This study aims to characterize the biological roles of Irisin signaling in an infrapatellar fat formation and OA development.

Injured articular specimens were harvested from 19 patients with end-stage knee OA and 11 patients with the femoral neck fracture. Knee joints in mice that overexpressed Irisin were subjected to intra-articular injection of collagenase to provoke OA. Expressions of Irisin, adipokines, and MMPs probed with RT-quantitative PCR. Infrapatellar adiposity, articular cartilage damage, and synovial integrity verified with histomorphometry and immunohistochemistry.

Infrapatellar adipose and synovial tissues instead of articular cartilage exhibited Irisin immunostaining. Human OA specimens showed 40% decline in Irisin expression than the non-OA group. In vitro, the gain of Irisin function enabled synovial fibroblasts but not chondrocytes to display minor responses to the IL-1β provocation of MMP3 and MMP9 expression. Of note, Irisin signaling reduced adipogenic gene expression and adipocyte formation of mesenchymal progenitor cells. In collagenase-mediated OA knee pathogenesis, forced FNDC5 expression in articular compromised the collagenase-induced infrapatellar adipose hypertrophy, synovial hypercellularity, and membrane hyperplasia. These adipose-regulatory actions warded off the affected knees from cartilage destruction and gait aberrance. Likewise, intra-articular injection of Irisin recombinant protein mitigated the development of infrapatellar adiposity and synovitis slowing down the progression of cartilage erosion and walking profile irregularity. Affected joints and adipocytes responded to the Irisin recombinant protein treatment by reducing the expressions of cartilage-deleterious adipokines IL-6, leptin, and adiponectin through regulating PPAR&gamma, function.

Irisin dysfunction is relevant to the existence of end-stage knee OA. Irisin signaling protects from excessive adipogenesis of mesenchymal precursor cells and diminished inflammation and cartilage catabolism actions aggravated by adipocytes and synovial cells. This study sheds emerging new light on the Irisin signaling stabilization of infrapatellar adipose homeostasis and the perspective of the therapeutic potential of Irisin recombinant protein for deescalating knee OA development.

S. Mann M. Tohidi M. M. Harrison A. Campbell K. Lajkosz E. VanDenKerkhof

The purpose of this population-based study was to determine the association between morbid obesity and 10-year mortality and complications in patients undergoing primary THA.

A cohort study of 22,251 patients, aged 45–74 years old, treated with primary THA between 2002 and 2007 for osteoarthritis, was conducted using Ontario administrative healthcare databases. Patients were followed for 10 years. Risk ratios (RRs) of mortality, reoperation, revision, and dislocation in patients with body mass index (BMI) > 45 kg/m2(morbidly obese patients) compared with BMI ≤45 kg/m2 (non-morbidly obese) were estimated.

3.3% of the cohort (726) was morbidly obese. Morbidly obese patients were younger (mean age 60.6 vs. 63.3, P-value < 0 .001) and more likely to be female (63.9% vs. 52.2%, P-value < 0 .001), compared with non-morbidly obese patients. Morbid obesity was associated with higher 10-year risk of death (RR 1.38, 95% CI 1.18, 1.62). Risks of revision (RR 1.43, 95% CI 0.96, 2.13) and dislocation (RR 2.38, 95% CI 1.38, 4.10) were higher in morbidly obese men, compared with non-morbidly obese men, there were no associations between obesity and revision or dislocation in women. Risk of reoperation was higher in morbidly obese women, compared to non-morbidly obese women (RR 1.60, 95% CI 1.05, 2.40), there was no association between obesity and reoperation in men.

Morbidly obese patients undergoing primary THA are at higher risks of long-term mortality and complications. There were differences in complication risk by sex. Results should inform evidence-based perioperative counseling of morbidly obese patients considering THA.

G. Gkagkalis K. P. Kutzner P. Goetti S. Mai I. Meinecke N. Helmy B. Solothurn D. Bosson

Short-stem total hip arthroplasty (THA) has primarily been recommended for young and active patients, mainly due to its bone preserving philosophy. Elderly patients, however, may also benefit of a minimally invasive technique due to the short and curved implant design. The purpose of this study was to compare the clinical and radiological outcomes as well as perioperative complications of a calcar-guided short stem between a young (75 years) population.

Data were collected in a total of 5 centers, and 400 short stems were included as part of a prospective multicentre observational study between 2010 and 2014 with a mean follow-up of 49.2 months. Clinical and radiological outcomes were assessed in both groups. Secondary outcomes such as perioperative complications, rates and reasons for stem revision were also investigated.

No differences were found for the mean visual analogue scale (VAS) values of rest pain, load pain, and satisfaction. Harris Hip Score (HHS) was found to be slightly better in the young group. Comparing both groups, no statistically significant differences ere found in the radiological parameters that were assessed (stress-shielding, cortical hypertrophy, radiolucency, osteolysis). Aseptic loosening was the main cause of implant failure in younger patients whereas in elderly patients, postoperative periprosthetic fractures due to accidental fall was found to be the main cause for stem revision.

These short-term results are encouraging towards the use of a cementless short stem in the geriatric population. According to our findings, advanced age and potentially reduced bone quality should not necessarily be considered as contra-indications for calcar-guided short-stem THA but careful and reasonable selection of the patients is mandatory. Longer follow up is necessary in order to draw safer conclusions.

V. Le M. Escudero K. Wing A. S. E. Younger M. Penner A. Veljkovic

Restoration of ankle alignment is thought to be critical in total ankle arthroplasty (TAA) outcomes, but previous research is primarily focused on coronal alignment. The purpose of this study was to investigate the sagittal alignment of the talar component. The talar component inclination, measured by the previously-described gamma angle, was hypothesized to be predictive of TAA outcomes.

A retrospective review of the Canadian Orthopaedic Foot and Ankle Society (COFAS) database of ankle arthritis was performed on all TAA cases at a single center over a 11-year period utilizing one of two modern implant designs. Cases without postoperative x-rays taken between 6 and 12 weeks were excluded. The gamma angle was measured by two independent orthopaedic surgeons twice each and standard descriptive statistics was done in addition to a survival analysis. The postoperative gamma angles were analyzed against several definitions of TAA failure and patient-reported outcome measures from the COFAS database by an expert biostatistician.

109 TAA cases satisfied inclusion and exclusion criteria. An elevated postoperative gamma angle higher than 22 degrees was associated with talar component subsidence, defined as a change in gamma angle of 5 degrees or more between postoperative and last available followup radiographs. This finding was true when adjusting for age, gender, body mass index (BMI), and inflammatory arthritis status. All measured angles were found to have good inter- and intraobserver reliability.

Surgeons should take care to not excessively dorsiflex the talar cuts during TAA surgery. The gamma angle is a simple and reliable radiographic measurement to predict long-term outcomes of TAA and can help surgeons counsel their patients postoperatively.

M. Farzi J. M. Pozo E. McCloskey R. Eastell A. Frangi J. M. Wilkinson

In conventional DXA (Dual-energy X-ray Absorptiometry) analysis, pixel bone mineral density (BMD) is often averaged at the femoral neck. Neck BMD constitutes the basis for osteoporosis diagnosis and fracture risk assessment. This data averaging, however, limits our understanding of localised spatial BMD patterns that could potentially enhance fracture prediction. DXA region free analysis (RFA) is a validated toolkit for pixel-level BMD analysis. We have previously deployed this toolkit to develop a spatio-temporal atlas of BMD ageing in the femur. This study aims first to introduce bone age to reflect the overall bone structural evolution with ageing, and second to quantify fracture-specific patterns in the femur.

The study dataset comprised 4933 femoral DXA scans from White British women aged 75 years or older. The total number of fractures was 684, of which 178 were reported at the hip within a follow-up period of five years. BMD maps were computed using the RFA toolkit. For each BMD map, bone age was defined as the age for which the L2-norm between the map and the median atlas at that age is minimised. Next, bone maps were normalised for the estimated bone age. A t-test followed by false discovery rate (FDR) analysis was applied to compare between fracture and non-fracture groups.

Excluding the ageing effect revealed subtle localised patterns of loss in BMD oriented in the same direction as principal tensile curves. A new score called f-score was defined by averaging the normalised pixel BMD values over the region with FDR q-value less than 1e–6. The area under the curve (AUC) was 0.731 (95% confidence interval (CI)=0.689–0.761) and 0.736 (95% CI=0.694–0.769) for neck BMD and f-score. Combining bone age and f-score improved the AUC significantly by 3% (AUC=0.761, 95% CI=0.756–0.768) over the neck BMD alone (AUC=0.731, 95% CI=0.726–0.737).

This technique shows promise in characterizing spatially-complex BMD changes, for which the conventional region-based technique is insensitive. DXA RFA shows promise to further improve fracture prediction using spatial BMD distribution.

M. Tibbo M. Houdek K. Bakri S. Sems S. Moran

The rate of fracture and subsequent nonunion after radiation therapy for soft-tissue sarcomas and bone tumors has been demonstrated to quite high. There is a paucity of data describing the optimal treatment for these nonunions. Free vascularized fibular grafts (FVFG) have been used successfully in the treatment of large segmental bone defects in the axial and appendicular skeleton, however, their efficacy with respect to treatment of radiated nonunions remains unclear. The purpose of the study was to assess the 1) union rate, 2) clinical outcomes, and 3) complications following FVFG for radiation-induced femoral fracture nonunions.

We identified 24 patients who underwent FVFG for the treatment of radiation-induced femoral fracture nonunion between 1991 and 2015. Medical records were reviewed in order to determine oncologic diagnosis, total preoperative radiation dose, type of surgical treatment for the nonunion, clinical outcomes, and postoperative complications. There were 11 males and 13 females, with a mean age of 59 years (range, 29 – 78) and a mean follow-up duration of 61 months (range, 10 – 183 months). Three patients had a history of diabetes mellitus and three were current tobacco users at the time of FVFG. No patient was receiving chemotherapy during recovery from FVFG. Oncologic diagnoses included unspecified soft tissue sarcomas (n = 5), undifferentiated pleomorphic sarcoma (UPS) (n = 3), myxofibrosarcoma (n = 3), liposarcoma (n = 2), Ewing's sarcoma (n = 2), lymphoma (n = 2), hemangiopericytoma, leiomyosarcoma, multiple myeloma, myxoid chondrosarcoma, myxoid liposarcoma, neurofibrosarcoma, and renal cell carcinoma.

Mean total radiation dose was 56.3 Gy (range, 39 – 72.5), given at a mean of 10.2 years prior to FVFG. The average FVFG length was 16.4 cm. In addition to FVFG, 13 patients underwent simultaneous autogenous iliac crest bone grafting, nine had other cancellous autografting, one received cancellous allograft, and three were treated with synthetic graft products. The FVFG was fixed as an onlay graft using lag screws in all cases, additional fixation was obtained with an intramedullary nail (n = 19), dynamic compression plate (n = 2), blade plate (n = 2), or lateral locking plate (n = 1).

Nineteen (79%) fractures went on to union at a mean of 13.1 months (range, 4.8 – 28.1 months). Musculoskeletal Tumor Society scores improved from eight preoperatively to 22 at latest follow-up (p < 0.0001). Among the five fractures that failed to unite, two were converted to proximal femoral replacements (PFR), two remained stable pseudarthroses, and one was converted to a total hip arthroplasty. A 6th case did unite initially, however, subsequent failure lead to PFR. Seven patients (29%) required a second operative grafting. There were five additional complications including three infections, one wound dehiscence, and one screw fracture. No patient required amputation.

Free vascularized fibular grafts are a reliable treatment option for radiation-induced pathologic femoral fracture nonunions, providing a union rate of 79%. Surgeons should remain cognizant, however, of the elevated rate of infectious complications and need for additional operative grafting procedures.

N. Rollick D. Helfet J. Bear O. Diamond D. Wellman

Malreduction of the syndesmosis is a poor prognosticator following ankle fracture and has been documented in as many as 52% of patients following fracture fixation. The current standard for assessment of reduction of the syndesmosis is bilateral computed tomography (CT) scan of the ankle. Multiple radiographic parameters are utilized to define malreduction, however, there has been limited investigation into the accuracy of these measurements to differentiate malreduction from inherent anatomical asymmetry. The purpose of this study was to identify the prevalence of positive malreduction standards within the syndesmosis of native, uninjured ankles.

Bilateral lower extremity CT scans including ankles were screened. Studies were excluded if the patient was skeletally immature, had pathology below the knee or if they had congenital neuromuscular syndromes. The resulting cohort consisted of 207 patients. The indication for bilateral CT scan was femoral acetabular impingement in 110 patients (53%), rotation assessment following arthroplasty in 32 patients (15%), rotation assessment following femoral fracture in 30 patients (14%), rotational assessment for patellar instability in 30 patients (14%) and five miscellaneous indications (2%).

Fifty patients were reviewed by three observers independently and to determine inter-observer reliability. A single observer repeated the measurements within the same cohort four weeks later to evaluate intra-observer reliability. Three observers then measured the anterior syndesmotic distance, posterior syndesmotic distance, central syndesmotic distance, fibular rotation and sagittal fibular translation at 1cm from the distal tibial articular surface. Overall side to side variability between the left and right ankle were assessed. Previously studied malreduction standards were evaluated. These included: anterior to posterior syndesmotic distance > 2mm, central syndesmotic difference > 1.5mm, average syndesmotic distance > 2mm, fibular rotational difference > 10o and sagittal translational difference > 2mm.

The inter- and intra-observer reliability was good to excellent for anterior, posterior and central syndesmotic distance, and fibular rotation measurements. Sagittal fibular translation had an ICC of 0.583, and thus was only of fair reliability. Side to side comparison revealed statistically significant difference in only anterior syndesmotic difference (p=0.038). A difference of anterior to posterior syndesmotic distance of greater than 2mm was observed in 43 patients (20.2%). Thirty eight patients (17.8%) had a central syndesmotic difference of greater than 1.5mm. A fibular rotational difference of greater than 10o was observed in 49 patients (23%). The average difference between the anterior and posterior syndesmosis was greater than 2mm in 17 patients (8.2%). Nine patients (4.2%) had sagittal translation of greater than 2mm.

Eighty one patients (39%) demonstrated at least one parameter beyond previously set standards for malreduction. Only one parameters was anomalous in 54 patients (26%), 18 patients (8%) had two positive parameters, while eight patients (4%) had three. One patient was asymmetrical in all measured parameters.

In this study there was no statistically significant asymmetry between ankles. However, 39% of native syndesmoses would be classified as malreduced on CT scan using previously studied malreduction limits. Current radiographic parameters are not sufficient to differentiate mild inherent anatomical asymmetry from malreduction of the syndesmosis.

N. Rollick J. Bear O. Diamond D. Helfet D. Wellman

Dual plating of the medial and lateral distal femur has been proposed to reduce angular malunion and hardware failure secondary to delayed union or nonunion. This strategy improves the strength and alignment of the construct, but it may compromise the vascularity of the distal femur paradoxically impairing healing. This study investigates the effect of dual plating versus single plating on the perfusion of the distal femur.

Ten matched pairs of fresh-frozen cadaveric lower extremities were assigned to either isolated lateral plating or dual plating of a single limb. The contralateral lower extremity was used as a matched control. A distal femoral locking plate was applied to the lateral side of ten legs using a standard sub-vastus approach. Five femurs had an additional 3.5mm reconstruction plate applied to the medial aspect of the distal femur using a medial sub-vastus approach.

The superficial femoral artery and the profunda femoris were cannulated at the level of the femoral head. Gadolinium MRI contrast solution (3:1 gadolinium to saline ration) was injected through the arterial cannula. High resolution fat-suppressed 3D gradient echo sequences were completed both with and without gadolinium contrast. Intra-osseous contributions were quantified within a standardized region of interest (ROI) using customized IDL 6.4 software (Exelis, Boulder, CO). Perfusion of the distal femur was assessed in six different zones. The signal intensity on MRI was then quantified in the distal femur and comparison was made between the experimental plated limb and the contralateral, control limb. Following completion of the MRI protocol, the specimens were injected with latex medium and the extra-osseous vasculature was dissected.

Quantitative MRI revealed that application of the lateral distal femoral locking plate reduced the perfusion of the distal femur by 21.7%. Within the dual plating group there was a reduction in perfusion by 24%. There was no significant difference in the perfusion between the isolated lateral plate and the dual plating groups. There were no regional differences in perfusion between the epiphyseal, metaphyseal or meta-diaphyseal regions.

Specimen dissection in both plating groups revealed complete destruction of any periosteal vessels that ran underneath either the medial or lateral plates. Multiple small vessels enter the posterior condyles off both superior medial and lateral geniculate arteries and were preserved in all specimens. Furthermore, there was retrograde flow to the distal most aspect of the condyles medially and laterally via the inferior geniculate arteries. The medial vascular pedicle was proximal to the medial plate in all the dual plated specimens and was not disrupted by the medial sub-vastus approach in any specimens.

Fixation of the distal femur via a lateral sub-vastus approach and application of a lateral locking plate results in a 21% reduction in perfusion to the distal femur. The addition of a medial 3.5mm reconstruction plate does not significantly compromise the vascularity of the distal femur. The majority of the vascular insult secondary to open reduction, internal fixation of the distal femur occurs with application of the lateral locking plate.

T. Boettcher C. A. Jones L. Beaupre S. H. Hyun Kang R. McLeod

Total joint arthroplasty (TJA) is often utilized to improve pain and dysfunction associated with end-stage osteoarthritis. Previous research has suggested that depression may negatively impact patient reported pain and function. The purpose of this study was to determine the effect of preoperative depressive symptoms, using the Center for Epidemiologic Scale for Depression (CES-D) scale, on patient reported function and pain at one, three and six months following TJA, after controlling for the impact of age, sex, pain, joint replaced, and other comorbidities.

This was a secondary analysis of a prospective cohort of 710 patients aged 40 years and older who underwent elective primary TJA in the Edmonton zone. Participants were recruited pre-operatively and reported socio-demographics, comorbid conditions and medications (including depression medications where appropriate), each participant also completed the Western Ontario McMaster (WOMAC) Osteoarthritis Index and the CES-D scale preoperatively. Participants then completed the WOMAC and CES-D scale again at one, three, and six months postoperatively. Risk-adjusted longitudinal data analysis using a linear mixed regression model was performed, controlling for age, sex, joint replaced, chronic pain, comorbidity, social support and employment status.

THA participants had a mean age of 65.9±10.1 years and included 175 (57%) female while TKA participants had a mean age of 67.9±10.1 years and included 249 (61%) females. ‘Possible’ depressive symptoms (CES-D score 16–19) were identified in 58 (8.1%) participants while ‘probable’ depressive symptoms (CES-D score ≥20) were identified in 68 (9.6%) participants. The mean WOMAC pain and function scores, when analyzed using the linear mixed regression model, demonstrated improvement from baseline at one, three, and six months (p < 0 .001 for both pain and function models as well as over time). However, in the patients with possible and probable depressive symptoms, WOMAC pain scores were 7.6±1.5 and 11.7±1.3 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, chronic pain, comorbidities and social support. Similarly, WOMAC function scores in the patients with possible and probable depressive symptoms were 8.8±1.4 and 14.2±1.2 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, comorbidities and employment status.

Depressive symptoms negatively affect postoperative pain and function measured using WOMAC scales even after risk adjustment up to six-months post TJA. Screening for depressive symptomology both pre- and postoperatively may provide an opportunity to identify and manage depressive symptoms to improve postoperative pain and function.

F. Mahmood J. Burt O. Bailey J. Clarke J. Baines

In the vast majority of patients, the anatomical and mechanical axes of the tibia in the coronal plane are widely accepted to be equivalent. This philosophy guides the design and placement of orthopaedic implants within the tibia and in both the knee and ankle joints. However, the presence of coronal tibial bowing may result in a difference between these two axes and hence cause suboptimal placement of implanted prostheses. Although the prevalence of tibial bowing in adults has been reported in Asian populations, to date no exploration of this phenomenon in a Western population has been conducted. The aim of this study was to quantify the prevalence of coronal tibial bowing in a Western population.

This was an observational retrospective cohort study using anteroposterior long leg radiographs collected prior to total knee arthroplasty in our high volume arthroplasty unit. Radiographs were reviewed using a Picture Archiving and Communication System. Using a technique previously described in the literature for assessment of tibial bowing, two lines were drawn, each one third of the length of the tibia. The first line was drawn between the tibial spines and the centre of the proximal third of the tibial medullary canal. The second was drawn from the midpoint of the talar dome to the centre of the distal third of the tibial medullary canal. The angle subtended by these two lines was used to determine the presence of bowing. Bowing was deemed significant if more than two degrees. The position of the apex of the bow determined whether it was medial or lateral. Measurements were conducted by a single observer and 10% of measurements were repeated by the same observer and also by two separate observers to allow calculation of intraclass correlation coefficients (ICCs).

A total of 975 radiographs consecutively performed in the calendar years 2015–16 were reviewed, 485 of the left leg and 490 of the right. In total 399 (40.9%) tibiae were deemed to have bowing more than two degrees. 232 (23.8%) tibiae were bowed medially and 167 (17.1%) were bowed laterally. The mean bowing angle was 3.51° (s.d. 1.24°) medially and 3.52° (s.d. 1.33°) laterally. Twenty-three patients in each group (9.9% medial/13.7% lateral) were bowed more than five degrees. The distribution of bowing angles followed a normal distribution, with the maximal angle observed 10.45° medially and 9.74° laterally. An intraobserver ICC of 0.97 and a mean interobserver ICC of 0.77 were calculated, indicating excellent reliability.

This is the first study reporting the prevalence of tibial bowing in a Western population. In a significant proportion of our sample, there was divergence between the anatomical and mechanical axes of the tibia. This finding has implications for both the design and implantation of orthopaedic prostheses, particularly in total knee arthroplasty. Further research is necessary to investigate whether prosthetic implantation based on the mechanical axis in bowed tibias results in suboptimal implant placement and adverse clinical outcomes.

A. Cooper V. McCutcheon J. Smith I. Pike H. Chhina P. Sidhu

Supracondylar fractures of the humerus (SCH) are the most common fractures sustained following a fall among children. The majority of these fractures are mild, but the most severe injury types can result in a disruption to the nerves and blood supply resulting in limb threatening injuries and potential life-long disability. Better understanding of mechanisms of injury and child-related factors that influence injury, especially for severe cases, is crucial to identifying best practices and informing policy. We aim to stratify fractures and examine the associated mechanisms and circumstances of injury to identify best practices and inform supportive policy. In doing so, we plan to investigate why some children sustain more severe fractures than others by exploring mechanisms and locations of injury, and risk-taking behaviours.

A prospective, mixed-methods pilot study employing a child-led research design. Our approach links narratives from qualitative photo elicitation interviews (PEI) to mapped images of the locations of injury using geotagged photographs children have taken themselves, complications and injury outcomes, and an assessment of overall risk-taking tendencies.

Participants aged six-12, with the help of their photographs, were able to lay out the events leading up to, including, and following their injury. Much of this information was either not included in their medical charts or was markedly different. Themes included not being able to prevent the injury and being adventurous, as well as becoming more cautious afterwards. These can have applications to the necessity of exploration as well as possibilities to prevent injury or not. Thus, the in-depth, first-person retelling of injury mechanism illustrated the need for mechanistic data and statistics beyond injury location alone. Risk-taking behaviours, as scored by the Sensation Seeking Scale for Children, correlated to injury severity, which is known to be associated with poorer outcomes and long-lasting complications.

PEI of children sustaining SCH fractures in Vancouver reveals mechanisms of injury beyond those previously reported in literature and suggest the feasibility of a large-scale study. PEI in this age group allows for clarifications and a clearer picture of injury mechanism as well as context of injury. These aspects significantly affect our ability to determine the relationship between injury mechanism and injury severity. Mixed-methods analysis of child-directed data as well as quantitative injury demographics reveals unique translational knowledge which can be shared with clinicians, patients/care-givers, community-based health teams, and local policy makers to make timely and impactful improvements in injury prevention, clinical practice, and play structure safety.

M. Tohidi D. O'Sullivan P. Groome J. D. Yach

Flail chest and multiple rib fractures are common injuries in trauma patients. Several small randomized studies have suggested significant improvements in patient outcomes with surgical fixation, compared to nonoperative management, yet emerging population-level data report some conflicting results. The objectives of this study were to compare the results of surgical fixation and nonoperative management of multiple rib fractures and flail chest injuries and to assess whether effects varied by study design limitations, including risk of confounding by indication.

A comprehensive search of electronic databases (Medline, Embase, Web of Science) was performed to identify randomized controlled trials and observational studies. Random effects models were used to evaluate weighted risk ratios (RR) and mean differences (MD). Risk of confounding by indication was assessed for each study (low, medium, and high risk), and this categorization was used to stratify results for clinical outcomes. Publication bias was assessed.

Thirty-nine studies, with a total of 19,357 patients met inclusion criteria. Compared to nonoperative treatment, surgical fixation of flail chest and multiple rib fractures was associated with decreased risk of death (overall RR 0.40, 95% confidence interval (CI) 0.28–0.56), pneumonia (overall RR 0.70, 95% CI 0.52–0.93), tracheostomy (overall RR 0.62, 95% CI 0.41–0.93), and chest wall deformity (overall RR 0.16, 95% CI 0.06–0.42). However, many of the observational studies were at risk of confounding by indication, and results varied according to risk of confounding by indication. Differences in ventilator time, intensive care unit length of stay (LOS), hospital LOS, and return to work will be assessed (results pending).

Compared to nonoperative treatment, surgical fixation of flail chest and multiple rib fractures is associated with improved clinical outcomes. Discrepancies between some study results may be due to confounding by indication. Additional prospective randomized trials and high-quality observational studies are required to overcome potential threats to validity and to expand on existing evidence around optimal treatment of these injuries.

G. Webster S. Karmakar-Hore N. de Guia J. Di Bella E. Bohm N. Klazinga L. Slawomirski M. Kallen

The Canadian Institute for Health Information (CIHI) and the Organisation for Economic Co-operation and Development (OECD) have partnered to advance international patient-reported outcome measures (PROMs) collection and reporting standards for hip and knee arthroplasty. This project is part of the OECD's Patient-Reported Indicator Survey (PaRIS) initiative, which aims to address the need for internationally comparable patient-reported outcome and experience measures in order to better monitor health system performance and drive continuous improvement. PROMs are in varying stages of implementation across OECD health systems, with differences in collection and reporting practices across existing programs.

CIHI and the OECD are leading an international working group for PROMs in hip and knee replacement surgery in order to build consensus on PROMs data collection standards and develop indicators for international reporting. Working group members include patient representatives, clinicians, national arthroplasty registries, the International Society of Arthroplasty Registries (ISAR), experts in PROMs measurement, and government representatives of several OECD member countries. Activities of the working group focus on two main priorities: 1) Use existing PROMs programs to maximize pilot comparable reporting in OECD's Health at a Glance 2019 report, and 2) Advance new PROMs standards and data collection to maximize comparable reporting beyond Health at a Glance 2019.

An environmental scan of PROMs in hip and knee arthroplasty found that a number of countries are collecting this data, however, there are variations in survey instruments as well as administration and reporting methods within and across countries. As part of priority 1, the working group has achieved consensus on a number of aspects around pilot reporting. The project is compiling data from existing PROMs programs in order to report results in the Health at a Glance 2019 publication.

For priority 2, the most notable challenge is establishing an agreement across countries on common survey tools, as well as a minimum data set that works for all, given the disparities of existing collection across countries. Many international programs lack the flexibility to change PROMs tools or collections methods, and have concerns regarding the break in trend for PROMs data within their own countries if they were to change methods. The project is exploring the use of crosswalks and other opportunities for comparable reporting, such as the use of single-item anchor questions. To date, the working group continues to develop consensus on international standards for PROMs collection and reporting. Results of the international consensus building and work to date will be shared.

PROMs incorporate the patient's perspective into the delivery of treatments and care – such as hip and knee arthroplasty – that aim to improve a patient's quality of life. Alignment of standards in PROMs collection across countries will make comparable data available for reporting, in order to inform quality improvement initiatives within health systems to provide better care for patients. CIHI and the OECD will continue to work with member countries to develop international data collection and reporting standards for PROMs, and encourage the adoption of common approaches across countries.

P. Lapner O. Laneuville H. K. Uhthoff T. Zhang L. Howard J. Pollock S. Ruggiero G. Trudel

Tears of the rotator cuff tendons are a very common entity. Despite recent advances in arthroscopic rotator cuff repair, the re-tear rate remains high. Thus, new methods to improve healing rates following rotator cuff repair must be sought. The purpose of this prospective randomized double-blind controlled study is to compare the functional outcomes and healing rates of an adjuvant pre-operative bone microfracture technique prior to arthroscopic cuff repair.

Patients undergoing arthroscopic rotator cuff repair were randomized to receive either a percutaneous bone microfracture of the supraspinatus footprint or a “soft tissue needling” technique, in which the pin was passed through the peripheral edges of the rotator cuff, five-seven days prior to index surgery, under ultrasound guidance. Follow-ups were completed at 3, 6, 12 and 24 months post-operatively. Healing status was determined by ultrasound at 6 and 24 months. The primary objective was to compare the WORC score at 24 months. Secondary objectives included the healing status via ultrasound, the Constant, and the ASES scores. A sample size calculation determined that 90 patients provided 80% power to detect a statistical difference between groups.

Baseline demographic data did not differ between groups. No statistical differences were detected in the WORC outcome at any time points (p=0.47, baseline, p=0.60, 3 months, p=0.79, 6 months, p=0.50, 12 months, p=0.54, 24 months). Healing rates did not differ between groups (P=0.34) and no differences were observed in the ASES or Constant Scores at all time-points. Statistically significant improvements occurred in both groups from baseline to all time points in all clinical outcome scores (p < 0 .0001).

No statistically significant differences in primary or secondary outcomes were identified between pre-operative bone microfracture and soft tissue needling techniques prior to arthroscopic rotator cuff repair. This study does not support pre-operative microfracture as a adjuvant technique prior to arthroscopic cuff repair.

D. Rouleau F. Balg B. Benoit S. Leduc M. Malo G. Y. Laflamme

Treatment of proximal humerus fractures (PHF) is controversial in many respects, including the choice of surgical approach for fixation when using a locking plate. The classic deltopectoral (DP) approach is believed to increase the risk of avascular necrosis while making access to the greater tuberosity more difficult. The deltoid split (DS) approach was developed to respect minimally invasive surgery principles. The purpose of the present study (NCT-00612391) was to compare outcomes of PHF treated by DP and DS approaches in terms of function (Q-DASH, Constant score), quality of life (SF12), and complications in a prospective randomized multicenter study.

From 2007 to 2016, all patients meeting the inclusion/exclusion criteria in two University Trauma Centers were invited to participate in the study. Inclusion criteria were: PHF Neer II/III, isolated injury, skeletal maturity, speaking French or English, available for follow-up (FU), and ability to fill questionnaires. Exclusion criteria: Pre-existing pathology to the limb, patient-refusing or too ill to undergo surgery, patient needing another type of treatment (nail, arthroplasty), axillary nerve impairment, open fracture. After consent, patients were randomized to one of the two treatments using the dark envelope method. Pre-injury status was documented by questionnaires (SF12, Q-DASH, Constant score). Range of motion was assessed. Patients were followed at two weeks, six weeks, 3-6-12-18-24 months. Power calculation was done with primary outcome: Q-DASH.

A total of 92 patients were randomised in the study and 83 patients were followed for a minimum of 12 months. The mean age was 62 y.o. (+- 14 y.) and 77% were females. There was an equivalent number of Neer II and III, 53% and 47% respectively. Mean FU was of 26 months. Forty-four patients were randomized to the DS and 39 to the DP approach. Groups were equivalent in terms of age, gender, BMI, severity of fracture and pre-injury scores. All clinical outcome measures were in favor of the deltopectoral approach. Primary outcome measure, Q-DASH, was better statistically and clinically in the DP group (12 vs 26, p=0,003). Patients with DP had less pain and better quality of life scores than with DS (VAS 1/10 vs 2/10 p=0,019 and SF12M 56 vs 51, p=0,049, respectively). Constant-Murley score was higher in the DP group (73 vs 60, p=0,014). However, active external rotation was better with the DS approach (45° vs 35°). There were more complications in DS patients, with four screw cut-outs vs zero, four avascular necrosis vs one, and five reoperations vs two. Calcar screws were used for a majority of DP fixations (57%) vs a minority of DS (27%) (p=0,012).

The primary hypothesis on the superiority of the deltoid split incision was rebutted. Functional outcome, quality of life, pain, and risk of complication favoured the classic deltopectoral approach. Active external rotation was the only outcome better with DS. We believe that the difficulty of adding calcar screws and intramuscular dissection in the DS approach were partly responsible for this difference. The DP approach should be used during Neer II and III PHF fixation.

P. Tohme M. Hupin M. Nault C. Stanciu M. Beausejour R. Blondin-Gravel É. Désautels N. Jourdain

Premature growth arrests are an infrequent, yet a significant complication of physeal fractures of the distal radius in children and adolescents. Through early diagnosis, it is possible to prevent clinical repercussions of the anatomical and biomechanical alterations of the wrist. Their true incidence has not been well established, and there exists no consensual systematic monitoring plan for minimising its impacts

The main objective was to evaluate the prevalence of growth arrests after a physeal distal radius fracture. The secondary objective was to identify risk factors in order to better guide clinicians for a systematic follow-up. All patients seen between 2014–2016 in a tertiary orthopaedic clinic were retrospectively reviewed.

Inclusion criteria were (one) a physeal fracture of the distal radius (two) adequate clinical/radiological follow-up.

Descriptive, Chi-square and binary logistic regression analyses were carried out using SPSS software.

One hundred ninety patients (mean age: 12 ± 2.8 years) fulfilled the inclusion criteria. Forty percent (n=76) of the fractures were treated by closed reduction. Premature growth arrest was seen in 6.8% (n=13) and diagnosed at a mean of 10 months post trauma. The logistic regression showed that the initial translation percentage (>30%) (p 25) (p increase the risk of growth arrest. After adjusting for concomitant ipsilateral ulnar injuries, a positive association between physeal complications and fracture manipulation was detected (76.9%, p=0.03). A non-significant trend between premature growth arrest and associated ulnar injury was observed (p=0.054). No association was identified for trauma velocity, fracture type, gender and age, and growth complications.

A prevalence of 6.8% of growth arrest was found after a physeal fracture of the distal radius. Fractures presenting with an initial coronal translation > 30% and/or angulation > 25 from normal, as well as those treated by manipulation, have been shown to be at risk for a premature growth arrest of the distal radius.

This study highlights the importance of a systematic follow-up after a physeal fracture of the distal radius especially for patients with a more displaced fracture who had a closed reduction performed. An optimal follow-up period should be over 10 months to optimize the detection of growth arrest and treat it promptly, thereby minimizing negative clinical consequences.

S. Abdic N. Knowles J. Johnson G. Walch G. Athwal

Superiorly eroded glenoids in cuff tear arthropathy represent a surgical challenge for reconstruction. The bone loss orientation and severity may influence glenoid component fixation. This computed-tomography study quantifies both the degree of erosion and orientation in superiorly eroded Favard E2 glenoids. We hypothesized that the erosion in E2 glenoids does not occur purely superiorly, rather, it is oriented in a predictable posterosuperior orientation with a largely semicircular line of erosion.

Three-dimensional reconstructions of 40 shoulders with E2 glenoids (28 female, 12 male patients) at a mean age of 74 years (range, 56–88 years) were created from computed-tomography images. Point coordinates were extracted from each construct to analyze the morphologic structure. The anatomical location of the supra- and infraglenoid tubercle guided the creation of a superoinferior axis, against which the orientation angle of the erosion was measured. The direction and, thus, orientation of erosion was calculated as a vector. By placing ten point coordinates along the line of erosion and creating a circle of best fit, the radius of the circle was placed orthogonally against a chord that resulted by connecting the two outermost points along the line of erosion. To quantify the extent of curvature of the line of erosion between the paleo- and neoglenoid, the length of the radius of the circle of best fit was calculated. Individual values were compared against the mean of circle radii. The area of bony erosion (neoglenoid), was calculated as a percentage of the total glenoid area (neoglenoid + paleoglenoid). The severity of the erosion was categorized as mild (0% to 33%), moderate (34% to 66%), and severe erosion (>66%).

The mean orientation angle between the vector of bony erosion and the superoinferior axis of the glenoid was 47° ± 17° (range, 14° – 74°) located in the posterosuperior quadrant of the glenoid, resulting in the average erosion being directed between the 10 and 11 o'clock position (right shoulder).

In 63% of E2 cases, the line of erosion separating the paleo- and neoglenoids was more curved than the average of all bony erosions in the cohort. The mean surface area of the neoglenoid was 636 ± 247 mm2(range, 233 – 1,333 mm2) and of the paleoglenoid 311 ± 165 mm2(range, 123 – 820 mm2), revealing that, on average, the neoglenoids consume 67% of the total glenoid surface. The extent of erosion of the total cohort was subdivided into one mild (2%), 14 moderate (35%) and 25 severe (62%) cases.

Using a clock-face for orientation, the average orientation of type E2 glenoid defects was directed between the 10 and 11 o'clock position in a right shoulder, corresponding to the posterosuperior glenoid quadrant. Surgeons managing patients with E2 type glenoids should be aware that a superiorly described glenoid erosion is oriented in the posterosuperior quadrant on the glenoid clock-face when viewed intra-operatively. Additionally, the line of erosion in 63% of E2 glenoids is substantially curved, having a significant effect on bone removal techniques when using commercially available augments for defect reconstruction.

D. Lin

Post-traumatic osteonecrosis of the femoral head (ONFH) is a major complication of femoral neck fractures that require numerous solutions. The purpose of the current study is to investigate the effects of platelet-rich plasma (PRP) incorporated autologous granular bones graft for the treatment of pre-collapse stages (ARCO stage II-III) of post-traumatic ONFH.

A total of 46 patients were eligible and enrolled into the study. 24 patients were treated with core decompression and PRP incorporated autologous granular bones graft (treatment group: 9 females and 15 males, age range, 16–39 years), and 22 patients with core decompression and autologous granular bones graft (control group: 6 females and 16 males, age range, 18–42 years. During a minimum duration of follow-up of 36 months, multiple imaging techniques including X-ray and computed tomography (CT) scanning were used to evaluate the radiological results, and Harris hip score (HHS) and the visual analogue scale (VAS) were chosen to assess the clinical results.

Both treatment group and control group had a significant improved HHS (P < 0.001). The minimum clinically important difference (MCID) for HHS was reached in 91.7% of treatment group and 68.2% of control group (P = 0.0449). HHS in treatment group was significantly higher than control group at the last follow-up (P = 0.0254). VAS score was significantly declined in treatment group when compared with control group (P = 0.0125). Successful clinical results were achieved in 21 of 24 patients (87.5%) in treatment group compared with 13 of 22 patients (59.1%) in control group (P = 0.0284). Successful radiological results were achieved in 19 of 24 patients (79.2%) in treatment group compared with 11 of 22 patients (50%) in control group (P = 0.0380). The survival rates using requirement for further hip surgery as an endpoint were higher in treatment group in comparison to control group (P = 0.0260).

The PRP incorporated autologous granular bones graft is a safe and effective procedure for the treatment of pre-collapse stages (ARCO stage II-III) of post-traumatic ONFH.

L. M. Epure M. Grant F. Mwale J. Antoniou A. Bolt K. Mann H. Chou

Tungsten has been increasing in demand for use in manufacturing and recently, medical devices, as it imparts flexibility, strength, and conductance of metal alloys. Given the surge in tungsten use, our population may be subjected to elevated exposures. For instance, embolism coils made of tungsten have been shown to degrade in some patients. In a cohort of breast cancer patients who received tungsten-based shielding for intraoperative radiotherapy, urinary tungsten levels remained over tenfold higher 20 months post-surgery. In vivo models have demonstrated that tungsten exposure increases tumor metastasis and enhances the adipogenesis of bone marrow-derived mesenchymal stem cells while inhibiting osteogenesis. We recently determined that when mice are exposed to tungsten [15 ppm] in their drinking water, it bioaccumulates in the intervertebral disc tissue and vertebrae. This study was performed to determine the toxicity of tungsten on intervertebral disc.

Bovine nucleus pulposus (bNP) and annulus fibrosus (bAF) cells were isolated from bovine caudal tails. Cells were expanded in flasks then prepared for 3D culturing in alginate beads at a density of 1×106 cells/mL. Beads were cultured in medium supplemented with increasing tungsten concentrations in the form of sodium tungstate [0, 0.5, 5, 15 ug/mL] for 12 days. A modified GAG assay was performed on the beads to determine proteoglycan content and Western blotting for type II collagen (Col II) synthesis. Cell viability was determined by counting live and dead cells in the beads following incubation with the Live/Dead Viability Assay kit (Thermo Fisher Scientific). Cell numbers in beads at the end of the incubation period was determined using Quant-iT dsDNA Assay Kit (Thermo Fisher Scientific)

Tungsten dose-dependently decreased the synthesis of proteoglycan in IVD cells, however, the effect was significant at the highest dose of 15 ug/mL. (n=3). Furthermore, although tungsten decreased the synthesis of Col II in IVD cells, it significantly increased the synthesis of Col I. Upregulation of catabolic enzymes ADAMTS4 and −5 were also observed in IVD cells treated with tungsten (n=3). Upon histological examination of spines from mice treated with tungsten [15 ug/mL] in their drinking water for 30 days, disc heights were diminished and Col I upregulation was observed (n=4). Cell viability was not markedly affected by tungsten in both bNP and bAF cells, but proliferation of bNP cells decreased at higher concentration. Surprisingly, histological examination of IVDs and gene expression analysis demonstrated upregulation of NGF expression in both NP and AF cells. In addition, endplate capillaries showed increases in CGRP and PGP9.5 expression as determined on histological sections of mouse IVDs, suggesting the development of sensory neuron invasion of the disc.

We provide evidence that prolonged tungsten exposure can induce disc fibrosis and increase the expression of markers associated with pain. Tungsten toxicity may play a role in disc degeneration disease.

L. M. Epure M. Grant M. Alaqeel J. Antoniou F. Mwale

Osteoarthritis (OA) is a chronic degenerative joint disorder that affects millions of people. There are currently no therapies that reverse or repair cartilage degradation in OA patients. Link N (DHLSDNYTLDHDRAIH) is a naturally occurring peptide that has been shown to increase both collagen and proteoglycan synthesis in chondrocytes and intervertebral disc cells [1,2]. Recent evidence indicates that Link N activates Smad1/5 signaling in cultured rabbit IVD cells presumably by interacting with the bone morphogenetic protein (BMP) type II receptor [3], however, whether a similar mechanism exists in chondrocytes remains unknown. In this study we determined whether Link N can stimulate matrix production and reverse degradation of human OA cartilage under inflammatory conditions.

OA cartilage was obtained from donors undergoing total knee arthroplasty with informed consent. OA cartilage/bone explants and OA chondrocytes were prepared from each donor. Cells were prepared in alginate beads (2×106 cells/mL) for gene expression analysis using qPCR. Cells and cartilage explants were exposed to IL-1β (10ng/ml), human Link N (hLN) (1μg/ml) or co-incubated with IL-1β+hLN for 7 and 21 days, respectively. Media was supplemented every three days. Cartilage/bone explants were measured for total glycosaminoglycan (GAG) content (retained and released) using the dimethylmethylene blue (DMMB) assay. Western blotting was performed to determine aggrecan and collagen expression in cartilage tissue. To determine NFκB activation, Western blotting was performed for detection of P-p65 in chondrocytes cultured in 2D following 10 min exposure of IL-1β in the presence of 10, 100, or 1000 ng/mL hLN.

Link N significantly decreased in a dose-dependent manner IL-1β-induced NFκB activation in chondrocytes. Gene expression profiling of matrix proteins indicated that there was a trend towards increased aggrecan and decreased collagen type I expression following hLN and IL-1β co-incubation. HLN significantly decreased the IL-1β-induced expression of catabolic enzymes MMP3 and MMP13, and the neuronal growth factor NGF (p < 0 .0001, n=3). In OA cartilage/bone explants, hLN reversed the loss of proteoglycan in cartilage tissue and significantly increased its synthesis whilst in the presence of IL-1β.

Link N stimulated proteoglycan synthesis and decreased MMP expression in OA chondrocytes under inflammatory conditions. One mechanism for Link N in preserving matrix protein synthesis may, in part, be due to its ability in rapidly suppressing IL-1β-induced activation of NF-κB. Further work is needed to determine whether Link N directly inhibits the IL-1β receptor or interferes with NFκB activation through an independent pathway(s).

L. M. Epure M. Grant O. Salem O. L. Huk J. Antoniou F. Mwale

Osteoarthritis (OA) is a multifactorial debilitating disease that affects over four million Canadians. Although the mechanism(s) of OA onset is unclear, the biological outcome is cartilage degradation. Cartilage degradation is typified by the progressive loss of extracellular matrix components - aggrecan and type II collagen (Col II) – partly due to the up-regulation of catabolic enzymes - aggrecanases a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS-) 4 and 5 and matrix metalloproteinases (MMPs). There is currently no treatment that will prevent or repair joint damage, and current medications are aimed mostly at pain management. When pain becomes unmanageable arthroplastic surgery is often performed. Interest has developed over the presence of calcium crystals in the synovial fluid of OA patients, as they have been shown to activate synovial fibroblasts inducing the expression of catabolic agents. We recently discovered elevated levels of free calcium in the synovial fluid of OA patients and raised the question on its role in cartilage degeneration.

Articular cartilage was isolated from 5 donors undergoing total hip replacement. Chondrocytes were recovered from the cartilage of each femoral head or knee by sequential digestion with Pronase followed by Collagenase and expanded in DMEM supplemented with 10% heat-inactivated FBS. OA and normal human articular chondrocytes (PromoCell, Heidelberg, Germany) were transferred to 6-well plates in culture medium containing various concentrations of calcium (0.5, 1, 2.5, and 5 mM CaCl2), and IL-1β. Cartilage explants were prepared from the same donors and included cartilage with the cortical bone approximately 1 cm2 in dimension. Bovine articular cartilage explants (10 months) were used as a control. Explants were cultured in the above mentioned media, however, the incubation period was extended to 21 days. Immunohistochemistry was performed on cartilage explants to measure expression of Col X, MMP-13, and alkaline phosphatase. The sulfated glycosaminoglycan (GAG, predominantly aggrecan) content of cartilage was analyzed using the 1,9-dimethylmethylene blue (DMMB) dye-binding assay, and aggregan fragmentation was determined by Western blotting using antibody targeted to its G1 domain. Western blotting was also performed on cell lysate from both OA and normal chondrocytes to measure aggrecan, Col II, MMP-3 and −13, ADAMTS-4 and −5.

Ca2+ significantly decreased the proteoglycan content of the cartilage explants as determined by the DMMB assay. The presence of aggrecan and Col II also decreased as a function of calcium, in both the human OA and bovine cartilage explants. When normal and OA chondrocytes were cultured in medium supplemented with increasing concentrations of calcium (0.5–5 mM Ca2+), aggrecan and Col II expression decreased dose-dependently. Surprisingly, increasing Ca2+ did not induce the release of MMP-3, and −13, or ADAMTS-4 and-5 in conditioned media from OA and normal chondrocytes. Interestingly, inhibition of the extracellular calcium-sensing receptor CaSR) reversed the effects of calcium on matrix protein synthesis.

We provide evidence that Ca2+ may play a direct role in cartilage degradation by regulating the expression of aggrecan and Col II through activation of CaSR.

M. Grant F. Mwale J. Antoniou S. Bergeron A. Karaplis D. Panda

Osteoarthritis (OA) is a debilitating disease and the most common joint disorder worldwide. Although the development of OA is considered multifactorial, the mechanisms underlying its initiation and progression remain unclear. A prominent feature in OA is cartilage degradation typified by the progressive loss of extracellular matrix components - aggrecan and type II collagen (Col II). Cartilage homeostasis is maintained by the anabolic and catabolic activities of chondrocytes. Prolonged exposure to stressors such as mechanical loading and inflammatory cytokines can alter the phonotype of chondrocytes favoring cartilage catabolism, and occurs through decreased matrix protein synthesis and upregulation of catabolic enzymes such as aggrecanases (ADAMTS-) 4 and 5 and matrix metalloproteinases (MMPs). More recently, the endoplasmic reticulum (ER) stress response has been implicated in OA. The ER-stress response protects the cell from misfolded proteins however, excessive activation of this system can lead to chondrocyte apoptosis. Acute exposure of chondrocytes to IL-1β has been demonstrated to upregulate ER-stress markers (GADD153 and GRP78), however, it is unclear whether the ER-stress response plays a role on chronic IL-1β exposure. The purpose of this study was to determine whether modulating the ER stress response with tauroursodeoxycholic acid (TUDCA) in human OA chondrocytes during prolonged IL-1β exposure can alter its catabolic effects.

Articular cartilage was isolated from donors undergoing total hip or knee replacement. Chondrocytes were recovered from the cartilage of each femoral head or knee by sequential digestion with Pronase followed by Collagenase, and expanded in DMEM-low glucose supplemented with 10% FBS. Chondrocytes were expanded in flasks for one passage before being prepared for micropellet culture. Chondrocyte pellets were cultured in regular growth medium (Control), medium supplemented with IL-1β [10 ng/mL], TUDCA [100 uM] or IL-1β + TUDCA for 12 days. Medium was replaced every three days. Cartilage explants were prepared from the donors undergoing knee replacement, and included cartilage with the cortical bone approximately 1 cm2 in dimension. Explants were cultured in the above mentioned media, however, the incubation period was extended to 21 days. RNA was extracted using Geneaid RNA Mini Kit for Tissue followed by cDNA synthesis. QPCR was performed using Cyber Green mastermix and primers for the following genes: ACAN (aggreacan), COL1A1, COL2A1, COL10A1, ADAMTS-4, ADAMTS-5, MMP-3, and MMP-13, on an ABI 7500 fast qPCR system.

Although IL-1β did not significantly decrease the expression of matrix proteins, it did increase the expression of ADAMTS-4, −5, and MMP3 and −13 when compared to controls (Kruskal-Wallis, p < 0 .05, n=3). TUDCA treatment alone did not significantly increase the expression of catabolic enzymes but it did increase the expression of collagen type II. When IL-1β was coincubated with TUDCA, the expression of ADAMTS-4, ADAMTS-5, and MMP-13 significantly decreased by ∼40-fold, ∼10-fold, and ∼3-fold, respectfully.

We provide evidence that the catabolic activities of IL-1β on human cartilage can be abrogated through modulation of the ER stress response.

D. J. Stockton G. Tobias J. Pike P. Daneshvar T. J. Goetz

Compared to single-incision distal biceps repair (SI), double-incision repair (DI) theoretically allows for reattachment of the tendon to a more anatomically favorable position. We hypothesized that DI repair would result in greater terminal supination torque compared to SI repair for acute distal biceps ruptures.

In this retrospective cohort study, patients were included if they sustained an isolated, acute (° supinated position. Secondary outcomes included supination torque in 45° supinated, neutral, and 45° pronated positions, ASES elbow score, DASH, SF-12, and VAS. Power analysis revealed that at least 32 patients were needed to detect a minimum 15% difference in the primary outcome (β = 0.20). Statistical analysis was performed with significance level α = 0.05 using R version 3.4.1 (R Core Team 2017, Vienna, Austria).

Of 53 eligible patients, 37 consented to participate. Fifteen were repaired using DI technique and 22 using SI technique. Mean age was 47.3yrs and median follow-up time was 28.1months. The groups did not differ with respect to age, time-to-follow-up, dominance of arm affected, Workers Compensation or smoking status. Mean supination torque, measured as the percentage of the unaffected side, was 60.9% (95%CI 45.1–76.7) for DI repair versus 80.4% (95%CI 69.1–91.7) for SI repair at the 60°supinated position (p=0.036). There were no statistically significant differences in mean supination torque at the 45°supinated position: 67.1% (95%CI 49.4–84.7) for DI versus 81.8% (95%CI 72.2–91.4) for SI (p=0.102), at the neutral position: 88.8% (95%CI 75.2–102.4) for DI versus 97.6% (95%CI 91.6–103.7) for SI (p=0.0.170), and at the 45°pronated position: 104.5% (95%CI 91.1–117.9) for DI versus 103.4 (95%CI 97.2–109.6) for SI (p=0.0.862). No statistically significant differences were detected in the secondary outcomes ASES Pain, ASES Function, DASH scores, SF-12 PCS or MCS, or VAS Pain. A small difference was detected in VAS Function (median 1.3 for DI repair versus 0.5 for SI repair, p=0.023). In a multivariate linear regression model controlling for arm dominance, age, and follow-up time, SI repair was associated with a greater mean supination torque than DI repair by 19.6% at the 60°supinated position (p=0.011).

Contrary to our hypothesis, we found approximately a 20% mean improvement in terminal supination torque for acute distal biceps ruptures repaired with the single-incision technique compared to the double-incision technique. Patients uniformly did well with either technique, though we contend that this finding may have clinical significance for the more discerning, high-demand patient.

H. Qiu T. Cheng S. M. Chim S. Zhu H. Xu A. Qin C. Wang D. Teguh G. Zhang J. Tickner F. Yao A. Vrielink L. Smithers N. Pavlos J. Xu

Bone is a connective tissue that undergoes constant remodeling. Any disturbances during this process may result in undesired pathological conditions. A single nucleotide substitution (596T-A) in exon eight which leads to a M199K mutation in human RANKL was found to cause osteoclast-poor autosomal recessive osteopetrosis (ARO). Patients with ARO cannot be cured by hematopoietic stem cell transplantation and, without proper treatments, will die in their early age. To date, how this mutation alters RANKL function has not been characterized. We thus hypothesized that hRANKL M199 residue is a structural determinant for normal RANKL-RANK interaction and osteoclast differentiation. By sharing our findings, we aim to achieve an improved clinical outcome in treating bone-related diseases such as osteoporosis, ARO and osteoarthritis.

Site-directed mutagenesis was employed to create three rat RANKL mutants, replacing the methionine 200 (human M199 equivalent residue) with either lysine (M200K), alanine (M200A) or glutamic acid (M200E). Recombinant proteins were subsequently purified through affinity chromatography and visualized by Coomassie blue staining and western blot. MTS was carried out before osteoclastogenesis assay in vitro to measure the cellular toxicity. Bone resorption pit assay, immuno-fluorescent staining, luciferase reporter assay, RT-PCR, western blot and calcium oscillation detection were also conducted to explore the biological effect of rRANKL mutants. Computational modeling, thermal Shift Assay, western blot and protein binding affinity experiments were later carried out for structural analyses.

rRANKL mutants M200K/A/E showed a drastically reduced ability to induce osteoclast formation and did not demonstrate features of competitive inhibition against wild-type rRANKL. These mutants are all incapable of supporting osteoclastic polarization and bone resorption or activating RANKL-induced osteoclast marker gene transcription. Consistently, they were unable to induce calcium flux, and also showed a diminished induction of IκBa degradation and activation of NF-kB and NFATc1 transcriptional activity. Furthermore, the transcriptional activation of the antioxidant response element (ARE) crucial in modulating oxidative stress and providing cytoprotection was also unresponsive to stimulation with rM200s. Structural analyses showed that rM200 is located in a hydrophobic pocket critical for protein folding. Thermal shift and western blot assays suggested that rM200 mutants formed unstructured proteins, with disturbed trimerisation and the loss of affinity to its intrinsic receptors RANK and OPG.

Taken together, we first demonstrates the underlying cause of M199-meidated ARO in a cellular and molecular level by establishing a phenotype in BMMs similar to observed in human samples. Further investigation hints the structural significance of a hydrophobic pocket within the TNF-like region. Combined with pharmaceutical studies on small-molecule drugs, this finding may represent a therapeutic target motif for future development of anti-resorptive treatments.

M. Symes O. Gagne M. Penner A. Veljkovic A. S. E. Younger K. Wing

Numerous studies have demonstrated that concomitant lower back pain (LBP) results in worse functional outcomes in patients undergoing surgical treatment for the management of end stage hip and knee arthritis. However, no equivalent studies have analysed the impact of back pain on the outcomes of patients with end stage ankle arthritis. Furthermore, given that two widely accepted surgical options exist in the treatment of ankle arthritis, namely total ankle arthroplasty (TAA) and ankle arthrodesis (AA), it is possible that one surgical technique may be superior in patients with LBP. The aim of this study was to determine the incidence of LBP in people with ankle arthritis, analyse its effect on functional outcomes, and explore whether there was a treatment advantage from either TAA or AA.

Prospectively collected data from the Canadian Orthopaedic Foot and Ankle Society (COFAS) database of ankle arthritis was analysed in this study. All patients with ankle arthritis who underwent surgery performed by three fellowship-trained foot and ankle surgeons at a single institution between January 2003 and July 2012 were studied. Patient demographics were collected pre-operatively, including the absence or presence of back pain, and post-operative follow up was performed at 2 and 5 years, evaluating patient-reported functional outcome measures including the Ankle Arthritis Score (AAS) and the 36-item short form survey (SF-36). Using a linear regression model, a multivariate analysis was performed to examine the relationship between back pain, TAAs and AAs

In total, 451 patients were studied. 164 patients (36.4%) presented with concomitant LBP.

At presentation, the LBP group had worse AAS scores (54.8 vs 57.8 p

At 2 years postoperatively, the AAS score was the same in both groups (28.9 vs 26.8 p = 0.3), but patients with LBP had worse SF-36 PCS (42.1 vs 36.6 p 0.05) in any of the functional outcome scores at 2 or 5 years post-operatively.

The results of this study suggest there is no advantage of TAA over AA in the treatment of ankle arthritis in patients with concomitant lower back pain. Although pre-operative back pain resulted in worse SF-36 outcomes at 2 and 5 years post- operatively, this was not the case for AAS scores.

M. Nault S. Leduc X. W. Tan

This study aimed to evaluate the clinical outcomes of paediatric patients who underwent a retrograde drilling treatment for their osteochondritis dissecans (OCD) of the talus. The secondary purpose was to identify factors that are predictive of a failure of the treatment.

A retrospective study was done. All patients treated for talar OCD between 2014 and 2017 were reviewed to extract clinical and demographic information (age, sex, BMI, OCD size and stability, number of drilling, etc). Inclusion criteria were: (1) talar OCD treated with retrograde drilling, (2) less than 18 years, (3) at least one available follow up (4) stable lesion. Exclusion criteria was another type of treatment for a the talar OCD. Additionally, all pre-operative and post-operative medical imaging was reviewed. Outcome was classified based on the last follow-up appointment in two ways, first a score was attributed following the Berndt and Harty treatment outcome grading and second according to the necessity of a second surgery which was the failure group. Chi-square and Mann-Whitney tests were used to compared the success and failure group.

Seventeen patients (16 girls and 1 boy, average age: 14.8±2.1 years) were included in our study group. The mean follow up duration was 11.5 (±12) months. Among this population, 4/17 (24%) had a failure of the treatment because they required a second surgery. The treatment result grading according to Berndt and Harty outcome scale identified good results in 8/17 (47%) patients, fair results in 4/17(24%) patients and poor results in 5/17 (29%) patients. The comparisons for various patient variables taken from the medical charts between patients who had a success of the treatment and those who failed did not find any significant differences.

At a mean follow-up duration of 11.5 months, 76% of patients in this study had a successful outcome after talar OCD retrograde drilling. No statistically significant difference was identified between the success and failure group.

Talar OCD in a paediatric population is uncommon, and this study reviewed the outcome of retrograde drilling with the largest sample size of the literature. Retrograde drilling achieved a successful outcome in 76% of the cases and represents a good option for the treatment of stable talar OCD.

M. Nault M. Hupin C. Buteau L. Saad

Osteomyelitis and septic arthritis are common pathologies in young children. Because of their skeletal immaturity, children are particularly vulnerable to orthopaedic complications, including limb-length discrepancies, angular deformities, chondrolysis, etc. The primary objective of this study was to review the clinical follow up and outcomes of paediatric patients diagnosed with osteoarticular infections. The secondary purpose was to look for significant differences in the clinical characteristics between the one with and without complications.

Patients' medical charts, hospitalised between 2010 and 2016, were retrospectively reviewed. The inclusion criteria were: patients (1) aged of less than 10 years old (2) treated and followed for osteomyelitis of long bones of upper and lower extremities and/or septic arthritis (3) with at least one year of radiological follow up. The exclusion criterion was: (1) any concomitant chronic diseases. The information collected included demographic and clinical data. A late sequela was defined as a limb-length discrepancy superior to 5 mm or an abnormal articular angulation of more than 5°, or a symptomatic chondropathy. Patients were separated in two groups: with and without complications. Chi-square tests were used for categorical variables and Mann-Whitney U tests for continuous data in order to establish significant differences between both groups.

Of the 401 patients with osteomyelitis and/or septic arthritis treated in our tertiary paediatric hospital over 7 years, 50 met the inclusion criteria. There were 24 girls and 26 boys. The etiological agent was identified in 56% of the cases. Staphylococcus aureus was the predominant causal pathogen (50%), followed by Kingella kingae (19.2%). The mean follow up was 780 days. Six out of 50 (12%) patients had physeal or chondrolytic complications at the latest follow-up. The only significant difference between the 2 groups was the delay between onset of symptoms and initiation of antibiotic therapy (P = 0.039).

Only 12.5% of the patients were followed up at least one year. In the population of 50 skeletally immature patients without comorbidities, 12% had a sequela. The delay in initiating antibiotic treatment was significantly longer in the group with the presence of sequelae.

The results of this study reveal that there were low rates of outpatient follow-up reaching more than a year after an osteoarticular infection, thus raising the question about the importance of a follow up after such a diagnosis. Twelve percent of the patients had a growth or chondrolysis complication and this might be related to the delay before initiating antibiotic treatment.

J. Richards A. Overmann N. O'Hara G. P. Slobogean J. D'Alleyrand

Internal fixation remains the treatment of choice for non-displaced femoral neck fractures in elderly patients, whereas, arthroplasty is preferred for displaced fracture patterns. Given technological advancements in implant design and excellent long-term outcomes, arthroplasty may provide improved outcomes for the treatment of non-displaced femoral neck fractures. The aim of our study was to conduct a systematic review of the orthopaedic literature (1) to investigate the outcomes of internal fixation for the treatment of non-displaced and minimally displaced femoral neck fractures in elderly patients and (2) to compare the outcomes of patients treated with internal fixation to arthroplasty in this patient population.

Relevant articles were identified using PubMed, Embase, and CENTRAL databases. Manuscripts were included only if they contained (1) patients 60 years or older with (2) nondisplaced or minimally displaced (Garden I or II) femoral neck fractures (3) treated with internal fixation or arthroplasty or (4) separately reported outcomes in this patient population. The primary outcome was reoperation. Secondary outcomes included mortality, patient reported outcomes, length of hospital stay, infection, and transfusions. An a priori decision was made to classify studies into comparative or non-comparative groups. Comparative studies directly compared arthroplasty to internal fixation in the specific study population while the non-comparative studies included separate cohorts of patients treated with arthroplasty or internal fixation. A fixed-effects model was used to quantitatively pool study outcomes.

Twenty-five non-comparative studies were identified with a total of 22,020 patients, all of which were treated with internal fixation. The pooled incidence of reoperation after internal fixation was 14.4% (95% CI: 10.8 – 18.8). The incidence of mortality within one-year of injury was 14.4% (95% CI: 6.7 – 28.3), based on the reporting in 14 studies.

Three comparative studies were identified with a total of 360 patients (128 treated with arthroplasty and 232 treated with internal fixation). All three studies reported reoperation rates. The overall risk of reoperation was 3.1% in the arthroplasty group compared to 9.5% in the internal fixation group (relative risk: 0.30, 95% CI: 0.10 – 0.84, p= 0.02). Only two studies reported mortality. The relative risk of mortality in patients treated with arthroplasty compared to internal fixation was 2.54 (95% CI: 1.38 – 4.70, p= 0.003).

Internal fixation of minimally displaced femoral neck fractures in the elderly is associated with a risk of reoperation and mortality that exceeds 14%. Treatment with arthroplasty may reduce the risk of reoperation by 70%. However, this benefit maybe tempered by a potential increased risk of mortality associated with arthroplasty in this patient population.

X. Wang C. Aubin J. Rawlinson R. Armstrong

In posterior fixation for deformity correction and spinal fusion, there is increasing discussion around auxiliary rods secured to the pedicle screws, sharing the loads, and reducing stresses in the primary rods. Dual-rod, multiaxial screws (DRMAS) provide two rod mounting points on a single screw shaft to allow unique constructs and load-sharing at specific vertebrae. These implants provide surgical flexibility to add auxiliary rods across a pedicle subtraction osteotomy (PSO) or over multiple vertebral levels where higher bending loads are anticipated in primary rods. Other options include fixed-angle devices as multiple rod connectors (MRC) and variable-angle dominoes (VAD) with a single-axis rotation in the connection. The objective in this simulation study was to assess rod bending in adult spinal instrumentation across an osteotomy using constructs with DRMAS, MRC, or VAD multi-rod connections.

The study was performed using computer biomechanical models of two adult patients having undergone posterior instrumented spinal fusion for deformity. The models were patient-specific, incorporating the biomechanics of the spine, have been calibrated to assess deformity correction and intra- and postoperative loads across the instrumented spine. One traditional bilateral-rod construct was used as a control for six multi-rod configurations. Spinal fixation scenarios from T10 through S1 with the PSO at L4 were simulated on each patient-specific model. The multi-rod configurations were bilateral and unilateral DRMAS at L2 through S1 (B-DRMAS and U-DRMAS), bilateral DRMAS at L3 and L5 (Hybrid), bilateral MRC over L3-L5, bilateral and unilateral VAD over L3-L5 (B-VAD and U-VAD). Postoperative gravity plus 8-Nm flexion and extension loads were simulated and bending moments in the rods were computed and compared.

In the simulated control for each case (#1 & #2), average rod bending moments (of the right and left rods) at the PSO level were 6.7Nm & 5.5Nm, respectively, in upright position, 8.8Nm & 7.3Nm in 8-Nm flexion, and 4.6Nm & 3.7Nm in 8-Nm extension. When the primary rods of the multi-rod constructs were normalized to this control, the bending moments in the primary rods of Case #1 & #2 were respectively 57% & 58% (B-DRMAS), 54% & 62% (B-VAD), 60% & 61% (MRC), 72% & 69% (Hybrid), 81% & 70% (U-DRMAS), and 81% & 73% (U-VAD). Overall, the reduction in primary rod bending moments ranged from 19–46% for standing loads. Under simulated 8-Nm functional moments, the primary rod moments were reduced by 18–46% in flexion and 17–48% in extension. More rods and stiffer connections produced the largest reductions for the primary rods, but auxiliary rods had bending moments that varied from 49% lower to 13% higher than the primary ones.

Additional rods through DRMAS, MRC, and VAD connections noticeably reduced the bending loads in the primary rods compared with a standard bilateral-rod construct. Yet, bending loads in the auxiliary rods were higher or lower than those in the primary rods depending on the 3D spinal deformity and stiffness of the auxiliary rod connections. Additional studies and patient-specific analyses are needed to optimize instrumentation parameters that may improve load-sharing in these constructs.

J. M. Wilkinson A. Gartland D. Morell K. Shah P. Sudsok

Local and systemic concentrations of cobalt (Co) and chromium (Cr) ions may be elevated in patients with accelerated tribo-corrosion at prosthesis bearing surfaces and modular taper junctions. Previous studies by us and others have shown that exposure to these metals negatively affect the viability and function of osteoblasts and osteoclasts in vitro, with implications for bone health. More recently, we have observed an increase in total bone mineral density and reduced bone turnover (TRAP5b and osteocalcin) in patients with well-functioning metal-on-metal hip resurfacing (MOMHR). Here, we provide data to support the hypothesis that osteoclast differentiation and function is altered in this patient population, and that this effect is transferrable through their serum.

Patients with well-functioning MOMHR (n=18) at median follow-up of 8 years were individually matched for gender, age and time-since-surgery to a low-exposure group consisting of patients with metal-on-polyethylene total hip arthroplasty (THA). The median circulating concentrations of Co and Cr for the MOMHR group were 2.53µg/L and 2.5µg/L respectively, compared to 0.02µg/L and 0.03µg/L for the THA group. Monocyte fraction of peripheral blood was isolated from these patients, seeded onto dentine wafers and differentiated into osteoclasts using media supplemented with RANKL and M-CSF (osteoclastogenic media, OM). Cultures were monitored for the onset of resorption, following which they were treated with OM, autologous serum or serum from the other individual within the matched MOMHR - THA pair, all supplemented with RANKL and M-CSF. At the end of the culture, cells were TRAP stained and quantified for total osteoclast number, number of resorbing osteoclasts and percentage resorption using the CellD Software Package (Olympus, Southend-on-Sea, U.K.).

For cells differentiated in osteoclastogenic media, the resorbing ability of osteoclasts derived from MOMHR patients was reduced by 30% (P=0.046) compared to THA. Correlation analyses showed that chronic exposure to Co and Cr trends towards negative association with resorption ability of these osteoclasts (r = −0.3, P=0.06). Furthermore, the resorbing ability of osteoclasts generated from MOMHR patients and differentiated in autologous serum was reduced 33% (p < 0 .0001), whilst matched THA serum caused a smaller reduction of 14% (p < 0 .01). When cells derived from THA patients were differentiated in autologous serum, the resorbing ability of osteoclasts was similarly reduced by 35% (p < 0 .0001), whilst the matched MOMHR serum also caused a reduction of 21% (p < 0 .0001).

Reduced osteoclastogenic response of precursor cells from patients with higher circulating Co and Cr suggests an inherent change in their potential to differentiate into functional osteoclasts. The data also suggests that functional response of mature osteoclasts generated from patient precursor cells are dependent on the prior systemic metal concentrations and the presence of higher circulating CoCr in patients with MOMHR. These effects are modest, but may explain the subtle increase in systemic bone mineral density and decreased bone turnover observed in patients after 8 years exposure compared to age, sex, and exposure-time matched patients who received a conventional THA.

J. Tat J. Chong T. Powell P. A. Martineau

Anterior shoulder instability is associated with osseous defects of the glenoid and/or humeral head (Hill-Sachs lesions). These defects can contribute to the pathology of instability by engaging together. There is a need to continue to develop methods to preoperatively identify engaging Hill-Sachs lesions for determining appropriate surgical management.

The objective was to created a working moveable 3D CT model that allows the user to move the shoulder joint into various positions to assess the relationship between the Hill-Sachs lesion and the anterior glenoid rim. This technique was applied to a cohort series of 14 patients with recurrent anterior dislocation: 4 patients had undergone osteoarticular allografting of Hill-Sachs lesions and 10 control patients had undergone CT scanning to quantify bone loss but had no treatment to address bony pathology. A biomechanical analysis was performed to rotate each 3D model using local coordinate systems through a functional range using an open-source 3D animation program, Blender (Amsterdam, Netherlands). A Hill-Sachs lesion was considered “dynamically” engaging if the angle between the lesion's long axis and anterior glenoid was parallel.

In the classical vulnerable position of the shoulder (abduction=90, external rotation=0–135), none of the Hill-Sachs lesions aligned with the anterior glenoid in any of our patients (Figure 1). Therefore, we considered there to be a “low risk” of engagement in these critical positions, as the non-parallel orientation represents a lack of true articular arc mismatch and is unlikely to produce joint instability. We then expanded our search and simulated shoulder positions throughout a physiological range of motion for all groups and found that 100% of the allograft patients and 70% of the controls had positions producing alignment and were “high risk” of engagement (p = 0.18) (Table 1). We also found that the allograft group had a greater number of positions that would engage (mean 4 ± 1 positions of engagement) compared to our controls (mean 2 ± 2 positions of engagement, p = 0.06).

We developed a 3D animated paradigm to dynamically and non-invasively visualize a patient's anatomy and determine the clinical significance of a Hill-Sachs lesion using open source software and CT images. The technique demonstrated in this series of patients showed multiple shoulder positions that align the Hill-Sachs and glenoid axes that do not necessarily meet the traditional definition of engagement. Identifying all shoulder positions at risk of “engaging”, in a broader physiological range, may have critical implications towards selecting the appropriate surgical management of bony defects. We do not claim to doubt the classic conceptual definition of engagement, but we merely introduce a technique that accounts for the dynamic component of shoulder motion, and in doing so, avoid limitations of a static criteria assumed traditional definition (like size and location of lesion). Further investigations are planned and will help to further validate the clinical utility of this method.

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

S. Pelet R. Pelletier-Roy

Surgeries for reverse total shoulder arthroplasty (RTSA) significantly increased in the last ten years. Initially developed to treat patients with cuff tear arthropathy (CTA) and pseudoparalysis, wider indications for RTSA were described, especially complex proximal humerus fractures.

We previously demonstrated in patients with CTA a different sequence of muscular activation than in normal shoulder, with a decrease in deltoid activation, a significant increase of upper trapezius activation and slight utility of the latissimus dorsi. There is no biomechanical study describing the muscular activity in patients with RTSA for fractures. The aim of this work is to describe the in vivo action of RTSA in patients with complex fractures of the proximal humerus.

We conducted an observational prospective cohort study comparing 9 patients with RTSA for complex humerus fracture (surgery more than 6 months, healed tuberosities and rehabilitation process achieved) and 10 controls with normal shoulder function. Assessment consisted in a synchronized analysis of range of motion (ROM) and muscular activity on electromyography (EMG) with the use of 7 bipolar cutaneous electrodes, 38 reflective markers and 8 motion-recording cameras. Electromyographic results were standardized and presented in muscular activity (RMS) adjusted with maximal isometric contractions according to the direction tested. Five basic movements were evaluated (flexion, abduction, neutral external rotation, external rotation in 90° of abduction and internal rotation in 90° of abduction). Student t-test were used for comparative descriptive analysis (p < 0,05).

The overall range of motion with RTSA is very good, but lower than the control group: flexion 155.6 ± 10 vs 172.2 ± 13.9, p<0.05, external rotation at 90° 55.6 ± 25 vs 85.6 ± 8.8, p<0,05, internal rotation at 90° 37.8 ± 15.6 vs 52.2 ± 12, p<0,05. The three heads of the deltoid are more stressed during flexion and abduction in the RTSA group (p

The increased use of the 3 deltoid chiefs does not support the hypothesis proposed by Grammont when the RTSA is performed for a complex proximal humerus fracture. This can be explained by the reduced dispalcement of the rotation center of the shoulder in these patients compared to those with CTA. These patients also didn't present shoulder stiffness before the fracture. The maximal muscle activity of the trapezius in flexion and of the latissimus dorsi in flexion and abduction had not been described to date. These new findings will help develop better targeted rehabilitation programs. In addition, the significant role of the latissimus dorsi must question the risks of its transfer (L'Episcopo procedure) to compensate for external rotation deficits.

S. Pelet B. Lechasseur E. Belzile M. Rivard-Cloutier

Radial head fractures are common and mainly require a functional conservative treatment. About 20% of patients will present an unsatisfactory final functional result. There is, however, little data allowing us to predict which patients are at risk of bad evolve. This makes it difficult to optimize our therapeutic strategies in these patients. The aim of this study is to determine the personal and environmental factors that influence the functional prognosis of patients with a radial head fracture.

We realized over a 1-year period a prospective observational longitudinal cohort study including 125 consecutive patients referred for a fracture of the radial head in a tertiary trauma center. We originally collected the factors believed to be prognostic indicators: age, sex, socioeconomic status, factors related to trauma or fracture, alcohol, tobacco, detection of depression scale, and financial compensation. A clinical and radiological follow-up took place at 6 weeks, 3 months, 6 months, and 1 year. The main functional measurement tool is the Mayo Elbow Performance Score (MEPS) and the Disabilities of the Arm, Shoulder and Hand (DASH).

123 patients were included in the study. 114 patients required nonsurgical management. 102 patients completed the 1-year follow-up for the main outcome (89 for the DASH score). Two patients required an unplanned surgery and were excluded from analyses. At 1 year, the average MEPS was 96.5 (range, 65–100) and 81% of subjects had an excellent result (MEPS ≥90). The most constant factor to predict an unsatisfactory functional outcome (MEPS <90 or DASH >17) is the presence of depressive symptoms at the initial time of the study (P = 0.03 and P = 0.0009, respectively). This factor is present throughout the follow-up. Other observed factors include a higher socioeconomic status (P = 0.009), the presence of financial compensation (P = 0.027), and a high-velocity trauma (P = 0.04). The severity of the fracture, advanced age, female sex, and the nature of the treatment does not influence the result at 1 year. No factor has been associated with a reduction in range of motion.

Most of the radial head fractures heal successfully. We identified for the first time, with a valid tool, the presence of depressive symptoms at the time of the fracture as a significant factor for an unsatisfactory functional result. Early detection is simple and fast and would allow patients at risk to adopt complementary strategies to optimize the result.

S. Pelet E. Belzile L. Racine P. Beauchamp-Chalifour M. Nolet H. Messier D. Plante

Malnutrition is often associated with the advanced age and can be influenced by physical, mental, social and environmental changes. Hip fracture is a major issue and a prior poor nutritional status is associated with higher rates of perioperative complications and prolonged hospital length of stay.

Prospective observational cohort study performed in a Level one trauma center including 189 consecutive patients admitted for hip fracture. The main outcome measure was the Mini Nutritional Assessment (MNA), a specific tool validated for geriatric population. This questionnaire was performed at admission by an independent assessor, at the same time as a large set of demographic and functional data. Blood samples were tested for blood count and albuminemia. Two groups were constituted and analysed according to a MNA score ≥ 24 (lower limit for normal nutritional status). Factors explored included physical and mental items. Impact of malnutrition was determined on hospital length of stay (HLS), discharge in an adverse location than prior to admission (DAL), complications and mortality rate.

The rate of patients with malnutrition (or at risk) in this study is 47% (88 patients). Patients with a MNA < 24 are older (84.81 yrs ± 7.75 vs 80.41 ± 8.11, p<0,01), have more comorbidities (Charlson 2.8 ± 2.21 vs 1.67 ± 3.10, p<0,01), a more impaired mental (MMSE 19.39±8.55 vs 25.6±3.6, p<0,01) or physical status (MIF 105.3 ± 26.6 vs 121.8 ± 6.4, p< 0,01). Blood samples are not selective to detect malnutrition (p=0,64). Malnutrition is associated with a longer HLS (26.04±23.39 days vs 13.95±11.34 days, p<0,01), a greater DAL (58.9% vs 38.2%, p=0,02) and a higher one year mortality rate (23.9% vs 8.9 %, p<0,01).

The prevalence of malnutrition in a geriatric population admitted for hip fracture is high. Blood samples at admission have clearly a poor value and a systematic screening with the MNA is mandatory. An early diagnosis will target specific interventions to reduce the physical and socio-economic impact of the malnutrition. Future studies should focus on actions in the perioperative stage (fast-track surgery, nutritional protocols, analgesia) and their impact on the socio-economic burden.

A. Bishop M. Gillis G. Richardson W. Oxner L. Gauthier A. Hayward R. A. Glennie S. Scott

Objective evaluations of resident performance can be difficult to simulate. A novel competency based surgical OSCE was developed to evaluate surgical skill. The goal of this study was to test the construct validity comparing previously validated Ottawa scores (O-scores) and Orthopaedic in-training evaluation scores (OITE).

An OSCE designed to simulate typical general orthopaedic surgical cases was developed to evaluate resident surgical performance. Post-graduate year (PGY) 3–5 trainees have an encounter (interview and physical exam) with a standardized patient and perform a correlating surgery on a cadaver. Examiners evaluate all components of the treatment plan and provide an overall score on the OSCE and also provide an O-score on overall surgical performance. Convergent and divergent validity was assessed comparing OSCE scores to O-scores and OITE scores. SPSS was used for statistical analysis. ANOVA was used to compare PGY averages and Pearson correlation coefficients were calculated to compare OSCE versus O-score and OITE scores.

A total of 96 simulated surgical cases were evaluated over a 3 year period for 24 trainees. There was a significant difference in OSCE scores based on year of training. (PGY3 − 6.06/15, PGY4 − 8.16/15 and PGY5 − 11.14/15, p < 0 .001). OSCE and O-scores demonstrated a strong positive correlation of +0.89 while OSCE and OITE scores demonstrated a moderate positive correlation of 0.68.

OSCE scores demonstrated strong convergent and moderate divergent correlation. A positive trajectory based on level of training and stronger correlations with established, validated scores supports the construct validity of the novel surgical OSCE.

D. Vissa C. Lin S. Ganapathy D. Bryant D. Adhikari S. MacDonald B. Lanting E. Vasarhelyi J. Howard

Dexmedetomidine, an alpha 2 agonist, has been approved for providing sedation in the intensive care unit. Along with sedative properties, it has analgesic activity through its highly selective action on alpha 2 receptors. Recent studies have examined the use of dexmedetomidine as an adjuvant to prolong the duration of peripheral nerve blocks. Studies showing effectiveness of dexmedetomidine for adductor canal block in knee surgery are small. Also, its effectiveness has not been compared to Epinephrine which is a strong alpha and beta receptor agonist. In a previous study, we showed that motor sparing knee blocks significantly increased the duration of analgesia compared with periarticular knee infiltration using local anesthetic mixture containing Epinephrine following total knee arthroplasty (TKA). In this study, we compared two local anesthetic mixtures: one containing Dexmedetomidine and the other Epinephrine for prolongation of motor sparing knee block in primary TKA patients.

After local ethics board approval and gaining Notice of Compliance (NOC) from Health Canada for use of Dexmedetomidine perineurally, 70 patients between the ages 18 – 95 of ASA class I to III undergoing unilateral primary total knee arthroplasty were enrolled. Motor sparing knee block − 1) Adductor canal continuous catheter 2) Single shot Lateral Femoral Cutaneous Nerve block 3) Single shot posterior knee infiltration was performed in all patients using 60 ml mixture of 0.5% Ropivacaine, 10 mg Morphine, 30 mg Ketorolac. Patients randomized into the Dexmedetomidine group (D) received, in addition to the mixture, 1mcg/kg Dexmedetomidine and the Epinephrine (E) group received 200mcg in the mixture. The primary outcome was time to first rescue analgesia as a surrogate for duration of analgesia and secondary outcomes were NRS pain scores up to 24 hours and opioid consumption.

The time to first rescue analgesia was not significantly different between Epinephrine and dexmedetomidine groups, Mean and SD 18.45 ± 12.98 hours vs 16.63 ± 11.80 hours with a mean difference of 1.82 hours (95% CI −4.54 to 8.18 hours) and p value of 0.57. Pain scores at 4, 6, 12, 18 and 24 hours were comparable between groups. Mean NRS pain scores Epinephrine vs Dexmedetomidine groups were 1.03 vs 0.80 at 4 hours, 1.48 vs 3.03 at 6 hours, 3.97 vs 4.93 at 12 hours, 5.31 vs 6.18 and 6.59 v 6.12 at 24 hours. Opioid consumption was also not statistically significant between both groups at 6, 12 18, 24 hours (p values 0.18, 0.88, 0.09, 0.64 respectively).

Dexmedetomidine does not prolong the duration of knee motor sparing blocks when compared to Epinephrine for total knee arthroplasty. Pain scores and opioid consumption was also comparable in both groups. Further studies using higher dose of dexmedetomidine are warranted.

R. Nicolay R. Selley D. Johnson M. Terry V. Tjong

Malnutrition is an important consideration during the perioperative period and albumin is the most common laboratory surrogate for nutritional status. The purpose of this study is to identify if preoperative serum albumin measurements are predictive of infection following arthroscopic procedures.

Patients undergoing knee, shoulder or hip arthroscopy between 2006–2016 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients with an arthroscopic current procedural terminology code and a preoperative serum albumin measurement were included. Patients with a history of prior infection, including a non-clean wound class, pre-existing wound infection or systemic sepsis were excluded. Independent t-tests where used to compare albumin values in patients with and without the occurrence of a postoperative infection. Pre-operative albumin levels were subsequently evaluated as predictors of infection with logistic regression models.

There were 31,906 patients who met the inclusion criteria. The average age was 55.7 years (standard deviation (SD) 14.62) and average BMI was 31.7 (SD 7.21). The most prevalent comorbidities were hypertension (49.2%), diabetes (18.4%) and smoking history (16.9%). The average preoperative albumin was 4.18 (SD 0.42). There were 45 cases of superficial infection (0.14%), 10 cases of wound dehiscence (0.03%), 17 cases of deep infection (0.05%), 27 cases of septic arthritis or other organ space infection (0.08%) and 95 cases of any infection (0.30%). The preoperative albumin levels for patients who developed septic arthritis (mean difference (MD) 0.20, 95% CI, 0.038, 0.35, P = 0.015) or any infection (MD 0.14, 95% CI 0.05, 0.22, P = 0.002) were significantly lower than the normal population. Additionally, disseminated cancer, Hispanic race, inpatient status and smoking history were significant independent risk factors for infection, while female sex and increasing albumin were protective towards developing any infection. Rates of all infections were found to increase exponentially with decreasing albumin. The relative risk of infection with an albumin of 2 was 3.46 (95% CI, 2.74–4.38) when compared to a normal albumin of 4. For each albumin increase of 0.69, the odds of developing any infection decreases by a factor of 0.52.

This study suggests that preoperative serum albumin is an independent predictor of septic arthritis and all infection following elective arthroscopic procedures. Although the effect of albumin on infection is modest, malnutrition may represent a modifiable risk factor with regard to preventing infection following arthroscopy.

J. Yeoh P. Chin W. D. Regan B. Lim T. Sasyniuk E. Sayre

Glenoid failure remains the most common mode of total shoulder arthroplasty failures. Porous tantalum metal (Trabecular Metal™, Zimmer) have grown in popularity in hip and knee arthroplasty. First-generation porous tantalum metal-backed glenoid components demonstrated metal debris, resulted in failure, and were revised to second-generation glenoid implants. Evidence for second-generation porous tantalum metal implants in shoulder arthroplasty is sparse.1–4 The purpose of this study was to assess clinical and radiographic outcomes in a series of patients with second-generation porous tantalum glenoid components at a minimum two-years postoperative.

We retrospectively reviewed the clinical and radiographic outcomes of patients who received a second-generation porous tantalum glenoid component anatomic shoulder arthroplasty between May 2009 and December 2017 with minimum 24 months follow-up. The shoulder arthroplasties were performed by one of two senior fellowship-trained surgeons. We collected postoperative clinical outcome indicators: EQ5D visual analog scale (VAS), Western Ontario Osteoarthritis of the Shoulder (WOOS) Index, American Shoulder and Elbow Surgeons (ASES) Score, and Constant Score (CS). Radiographic review was performed by an independent fellowship-trained surgeon. The Endrizzi metal debris grading system1 was utilized to grade metal debris. We computed descriptive statistics and compared outcome scores between groups via the non-parametric Wilcoxon rank-sum test, with group-wise comparisons defined by: metal debris and humeral head migration (secondary analyses).

Thirty-five patients [23 male (65.7%) and 12 female (34.3%)] with 40 shoulder replacements participated in the study. Forty of 61 shoulders (65.6%) had an average of 64 ± 20.3 months follow-up (range 31 to 95). Average BMI was 27.5 ± 4.4 kg/m2 (range 19.5 to 39.1). The average postoperative EQ5D VAS at final follow-up was 74.6 ± 22.5, WOOS Index 87.9 ± 16.6, ASES Score 88.3 ± 10.9, and CS 80.4 ± 13. At final follow-up, 18 of 40 shoulders (45%) had metal debris [15 of 40 (37.5%) Endrizzi grade 1 and three of 40 (7.5%) Endrizzi grade 2], and 22 of 40 shoulders (55%) did not show evidence of metal debris. There was one non-revision reoperation (open subscapularis exploration), one shoulder with anterosuperior escape, three shoulders with glenoid radiolucencies indicative of possible glenoid loosening, and nine shoulders with superior migration of the humeral head (>2mm migration at final follow-up compared to immediate postoperative). When comparing postoperative scores between patients with vs without metal debris, we found no statistically significant difference in the EQ5D VAS, WOOS Index, ASES Score and CS. On further analyses, when comparing superior migration of the humeral head and postoperative outcomes scores, we found no statistically significant difference.

We report the longest published follow-up with clinical and radiographic outcomes of second-generation porous tantalum glenoid anatomic shoulder arthroplasties. In this series of patients, 45% of total shoulder arthroplasties with a second-generation porous tantalum glenoid implant had radiographic evidence of metal debris. This metal debris was not statistically associated with poorer postoperative outcomes. Further investigation and ongoing follow-up are warranted.

M. Tanzer C. Pedneault K. Smith

The pain of arthritic disorders occurs in a social and environmental context. Thus, the pain of arthritis not only can affect the patient, but also the spouse. Numerous investigations have shown that the spouses of individuals with persistent pain report lower levels of marital satisfaction, higher rates of depression and lower quality of life. For the vast majority of patients with osteoarthritis, total hip (THA) or total knee (TKA) arthroplasty results in a significant reduction in pain, emotional distress, disability and a significant improvement in their quality of life and function. Little is currently known about how these recovery-related changes impact on the spouse or the marital relationship.

Patients and their spouses were recruited within one-year following the arthroplasty surgery. Couples participated in a semi-structured interview and were each asked to recall their level of pain on a numerical rating scale from 1 to 10 before and after recovering from surgery, and provide a numerical rating score (10 points) for a set of seven questions pertaining to their level of disability in seven different activities of daily living. In addition, the spouses were asked to list in order of importance the ways in which the surgery of their spouse affected their overall quality of life. In total, 33 couples (66 respondents) answered the survey questionnaire. There were 17 male patients, 16 female patients who underwent 29 THAs and 4 TKAs.

With regard to pain, the spouses estimated their partner's pain, both preoperatively and at the time of the survey, to be at a significantly higher level than the patient's perception (p=0.05). The spouses perceived a greater improvement in family/home responsibilities, recreation and social activities, and in their occupation than that noted by the partner. After the arthroplasty, the spouses indicated that their lives had improved with respect to doing more activities/leisure (70%), because there partner had less suffering (61%), they had more independence/less caregiving (54%), it improved their marital relationship (54%), they had a better social/family life (27%) and they were able to travel (27%).

In addition to the patient, THA and TKA result in a significant improvement in quality of life and marital functioning of the spouse. This should not continue to be unrecognized as a significant benefit of the procedure.

M. Decker B. Lanting A. Z. M. Islam R. Klassen M. J. Walzak R. W. McCalden

HXLPE acetabular liners were introduced to reduce wear-related complications in THA. However, post-irradiation thermal free radical stabilization can compromise mechanical properties, leave oxidation-prone residual free radicals, or both. Reports of mechanical failure of HXLPE acetabular liner rims raise concerns about thermal free radical stabilization and in vivo oxidization on implant properties. The purpose of this study is to explore the differences in the mechanical, physical and chemical properties of HXLPE acetabular liner rims after extended time in vivo between liners manufactured with different thermal free radical stabilization techniques.

Remelted, single annealed and sequentially annealed retrieved HXLPE acetabular liners with in vivo times greater than 4.5 years were obtained from our implant retrieval laboratory. All retrieved liners underwent an identical sanitation and storage protocol. For mechanical testing, a total of 55 explants and 13 control liners were tested. Explant in vivo time ranged from 4.6 – 14 years and ex vivo time ranged from 0 – 11.6 years. Rim mechanical properties were tested by microindentation hardness testing using a Micromet II Vickers microhardness tester following ASTM standards. A subset of 16 explants with ex vivo time under one year along with five control liners were assessed for oxidation by FTIR, crystallinity by Raman spectroscopy, and evidence of microcracking by SEM.

No significant difference in in vivo or ex vivo was found between thermal stabilization groups in either set of explants studied. In the mechanically tested explants, there was no significant correlation between in vivo time and Vickers hardness in any thermal stabilization group. A significant correlation was found between ex vivo time and hardness in remelted liners (r=.520, p = .011), but not in either annealed cohort. ANCOVA with ex vivo time as a covariate found a significant difference in hardness between the thermal free radical stabilization groups (p 0.1) was found in retrieved remelted (25%), single annealed (100%) and sequentially annealed (75%) liner rims. Crystallinity was increased in the subsurface region relative to control liners for both annealed, but not remelted, liner rims. Hardness was increased in oxidized rims for both annealed cohorts but not in the remelted cohort. Microcracking was only found along the surface of one unoxidized remelted liner rim.

Mechanical properties were reduced at baseline and worsened after in vivo time for remelted HXLPE liner rims. Rim oxidation was detected in all groups. Oxidation was associated with increased crystallinity and hardness in annealed cohorts, but not remelted liners. Increased crystallinity and oxidation do not appear to be directly causing the worsened mechanical behavior of remelted HXLPE liner rims after extended in vivo time.

M. Alaqeel A. Crapser J. Tat J. Lee-Howes J. Schupbach I. Tamimi P. A. Martineau

Anterior cruciate ligament (ACL) injuries are frequent among athletes and a leading cause of time away from competition. Stability of the knee involves the ACL for limiting anterior tibial translation and the ALL (anterolateral ligament) to restrain internal rotation of the tibia. Present indications for treatment with a combined ACL-ALL reconstruction remain unclear and mostly subjective. We mathematically modeled the tibial plateau geometry to try and identify patients at risk of ACL injury, and develop an objective trigger point for the decision to proceed with additional surgery to optimize rotational stability in these higher risk patients. We hypothesized that an increased convexity and steepness of the posterior aspect of the lateral plateau would subject knees to higher rotational torques leading to potentially a higher risk of ACL injury.

The study design was a case-control study involving ACL reconstruction cases (n=68) and matched controls (n=68) between 2008–2015 at our institution. We used a two-dimensional approach, evaluating sagittal MRI images of the knee to model the posterior convexity of the lateral tibial plateau. Points were selected along the articular surface, and a least-squares regression was used to curve-fit a power function (y = a xn). In the equation, larger coefficient a and n represented steeper slopes. The cases and controls were compared using a Mann-Whitney-U test, and the statistical significance was set at α < 0.05. A subgroup analysis for females and males was also performed for the curve-fit coefficients.

We observed a significant difference in the tibial surface geometry between our ACL reconstruction cases and matched controls (Figure 1). The modeled power equation for our ACL cases had larger coefficients compared to controls for all groups. For all pooled subjects, coefficient a (ACL recon cases = 0.90 vs controls = 0.68, p < 0.0001) and coefficient n (ACL recon cases = 0.34 vs controls = 0.30, p = 0.07) (Table 1). For the statistically significant coefficient a, we found it had a sensitivity of 78.9% and specificity of 77.5% for the statistically significant coefficient a, we found it had a sensitivity of 78.9% and specificity of 77.5% for predicting injury, using a cut off coefficient of a = 0.78. The odds ratio was 12.6 [5.5 – 29].

The posterolateral cartilaginous slope of the tibial plateau was mathematically modeled in patients with ACL injury. Patients with ACL injury demonstrated abnormally steep and fast slopes compared to controls that may play predispose to ACL injury by increasing anterior translation forces and internal rotation torques sustained by their knee joint. A steeper slope may also explain high-grade pivot shifts on physical exam that are thought to be a relative indication for adding an associated ALL reconstruction. Our findings are promising for adding more objectivity to surgical decision-making, especially with identifying high-risk patients that may be candidates for combined ACL-ALL reconstructions.

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

K. Goulding R. Turcotte A. Tsimicalis U. Košir K. Mate C. Freeman

This study explored psychological functioning and coping styles in adult patients with localized and metastatic extremity soft-tissue sarcoma (STS) from diagnosis through survivorship in a single expert sarcoma center in Canada. Our analyses were driven by three main goals: 1) to develop a better understanding of the affective responses and coping mechanisms in patients who face this rare illness, 2) to identify areas of psychological functioning in which patients with STS experience most difficulties, and 3) to describe how these areas could be best addressed in clinical settings.

This descriptive qualitative study is a part of a larger mixed-methods study on health related quality of life (HRQoL) in adult patients with soft-tissue sarcoma treated between 2003 and 2018. Purposive sampling based on demographic and disease variables from all patients within a prospective database was utilized to ensure a representative patient population. Three formats of data collection were conducted in French and English, 2 online focus groups (total n=12), 2 in-person focus groups (total n=12), as well as individual semi-structured interviews (n=4). Data was analyzed using inductive thematic networks approach using the qualitative software N-Vivo 12. Codes were generated by 2 independent qualitative experts that captured key concepts referring to psychological functioning and coping mechanisms. Basic themes were clustered into organizing themes, which were later merged into a global theme. Attention was paid to deviant cases, and within-group dynamics during focus group discussion analysis. Any discrepancies or inconsistencies in coding were resolved in a consensus meeting. The final sample size was determined when data saturation was reached, and no new themes emerged.

Our analyses of psychological well-being and functioning revealed three main themes, mood, anxiety, and body image concerns. Feelings of depression and low mood were prominent, coinciding with physical symptoms and limitations especially during the phase of treatment and recovery. Women were more likely to report emotional volatility, while men tended to report more preoccupation. Loss of control and independence, anxiety related to illness recurrence, uncertainty about the future and facing one's mortality significantly impacted quality of life. Furthermore, while patients were more concerned with limb functionality, disfigurement and self-consciousness featured prominently in the narrative. Four adaptive coping styles were observed, positive reframing and optimism, finding a purpose, being proactive, and using humor. Among the maladaptive strategies, we noted passive acceptance, and avoidance and denial.

Psychological well-being is an important domain in the HRQoL of adult patients with extremity STS. Physicians and medical workers should encourage adaptive coping mechanisms such as positive reframing and optimism. Patients endorsing higher levels of psychological distress and maladaptive coping styles should be monitored for their well-being and multidisciplinary strategies employed to optimize psychological function and HRQoL.

L. Somerville A. Clout S. MacDonald D. Naudie R. W. McCalden B. Lanting

While Oxidized Zirconium (OxZr) femoral heads matched with highly cross-linked polyethylene (XLPE) have demonstrated the lowest rate of revision compared to other bearing couples in the Australian National Joint Registry, it has been postulated that these results may, in part, be due to the fact that a single company offers this bearing option with a limited combination of femoral and acetabular prostheses. The purpose of this study was to assess clinical and radiographic outcomes in a matched cohort of total hip replacements (THR) utilizing an identical cementless femoral stem and acetabular component with either an Oxidized Zirconium (OxZr) or Cobalt-Chrome (CoCr) femoral heads at a minimum of 10 years follow-up.

We reviewed our institutional database to identify all patients whom underwent a THR with a single cementless femoral stem, acetabular component, XLPE liner and OxZr femoral head with a minimum of 10 years of follow-up. These were then matched to patients who underwent a THR with identical prosthesis combinations with CoCr femoral head by gender, age and BMI. All patients were prospectively evaluated with WOMAC, SF-12 and Harris Hip Score (HHS) preoperatively and postoperatively at 6 weeks, 3 months, 1 and 2 years and every 2 years thereafter. Charts and radiographs were reviewed to determine the revision rates and survivorship (both all cause and aseptic) at 10 years for both cohorts. Paired analysis was performed to determine if differences exist in patient reported outcomes.

There were 208 OxZr THRs identified which were matched with 208 CoCr THRs. There was no difference in average age (OxZr, 54.58 years, CoCr, 54.75 years), gender (OxZr 47.6% female, CoCr 47.6% female), and average body max index (OxZr, 31.36 kg/m2, CoCr, 31.12 kg/m2) between the two cohorts. There were no significant differences preoperatively in any of the outcome scores between the two groups (WOMAC (p=0.449), SF-12 (p=0.379), HHS(p=0.3718)). Both the SF12 (p=0.446) and the WOMAC (p=0.278) were similar between the two groups, however the OxZr THR cohort had slightly better HHS compared to the CoCr THR cohort (92.6 vs. 89.7, p=0.039). With revision for any reason as the end point, there was no significant difference in 10 years survivorship between groups (OxZr 98.5%, CoCr 96.6%, p=0.08). Similarly, aseptic revisions demonstrated comparable survivorship rates at 10 year between the OxZr (99.5%) and CoCr groups (97.6%)(p=0.15).

Both THR cohorts demonstrated outstanding survivorship and improvement in patient reported outcomes. The only difference was a slightly better HHS score for the OxZr cohort which may represent selection bias, where OxZr implants were perhaps implanted in more active patients. Implant survivorship was excellent and not dissimilar for both the OxZr and CoCr groups at 10 years. Therefore, with respect to implant longevity at the end of the first decade, there appears to be no clear advantage of OxZr heads compared to CoCr heads when paired with XLPE for patients with similar demographics. Further follow-up into the second and third decade may be required to demonstrate if a difference does exist.

J. Legault T. Beveridge M. Johnson J. Howard S. MacDonald B. Lanting

With the success of the medial parapatellar approach (MPA) to total knee arthroplasty (TKA), current research is aimed at reducing iatrogenic microneurovascular and soft tissues damage to the knee. In an effort to avoid disruption to the medial structures of the knee, we propose a novel quadriceps-sparing, subvastus lateralis approach (SLA) to TKA. The aim of the present study is to compare if a SLA can provide adequate exposure of the internal compartment of the knee while reducing soft tissue damage, compared to the MPA. Less disruption of these tissues could translate to better patient outcomes, such as reduced post-operative pain, increased range of motion, reduced instances of patellar maltracking or necrosis, and a shorter recovery time.

To determine if adequate exposure could be achieved, the length of the skin incision and perimeter of surgical exposure was compared amongst 22 paired fresh-frozen cadaveric lower limbs (five females/six males) which underwent TKA using the SLA or MPA approach. Additionally, subjective observations which included the percent of visibility of the femoral condyles and tibial plateau, as well as the patellar tracking, were noted in order to qualify adequate exposure. All procedures were conducted by the same surgeon. Subsequently, to determine the extent of soft tissue damage associated with the approaches, an observational assessment of the dynamic and static structures of the knee was performed, in addition to an examination of the microneurovascular structures involved. Dynamic and static structures were assessed by measuring the extent of muscular and ligamentus damage during gross dissection of the internal compartment of the knee. Microneurovascular involvement was evaluated through a microscopic histological examination of the tissue harvested adjacent to the capsular incision.

Comparison of the mean exposure perimeter and length of incision was not significantly different between the SLA and the MPA (p>0.05). In fact, on average, the SLA facilitated a 5 mm larger exposure perimeter to the internal compartment, with an 8 mm smaller incision, compared to the MPA, additional investigation is required to assert the clinical implications of these findings. Preliminary analysis of the total visibility of the femoral condyles were comparable between the SLA and MPA, though the tibial plateau visibility appears slightly reduced in the SLA. Analyses of differences in soft tissue damage are in progress.

Adequate exposure to the internal compartment of the knee can be achieved using an incision of similar length when the SLA to TKA is performed, compared to the standard MPA. Future studies should evaluate the versatility of the SLA through an examination of specimens with a known degree of knee deformity (valgus or varus).

M. Aziz G. McIntosh M. G. Johnson C. G. Fisher M. Weber M. Goytan

Post-operative infection is a serious complication of spine surgery and can contribute to the strain on the healthcare system's resources. The purpose of this study is to determine what factors affect the risk of developing postoperative infection. We hypothesize that female gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, increased age, body mass index (BMI), American Society of Anaesthesiologists (ASA) score, blood loss, number of operative levels, operative time and undergoing non-elective surgery will increase the patients' risk of developing a post-operative infection.

A retrospective review of prospectively collected data within the Canadian Spine Outcome and Research Network (CSORN) was conducted. Data was analyzed using IBM-SPSS. Multivariable logistical regression analysis was conducted (odds ratios) to determine any association between the outcome and independent factors. Significance level was p < 0.05.

There were 7747 patients identified from the registry that had completed at least 12 weeks of follow up. There were 199 infections recorded representing a 2.6% risk of infection. There were no association found between the risk of developing a post operative infection and gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, ASA score, blood loss, number of operative levels and undergoing non-elective surgery. The following were associated with an increased risk of developing a post operative infection: Older age (adjusted OR=1.021, 95% CI=1.005–1.038, p < 0 .05), having an elevated BMI (adjusted OR=1.042, 95% CI=1.013–1.072, p < 0 .005), longer operative time (adjusted OR=1.002, 95% CI=1.001–1.004, p < 0 .001).

There is a 2.6% overall rate of post-operative spine infection across 20 Canadian centres. The factors that were associated with an increased risk of developing a post operative-infection were older age, increased BMI and longer operative time. This study establishes a benchmark against which the effectiveness of future interventions to reduce infection can be compared.

M. Aziz P. F. Jarzem G. McIntosh M. Weber

Seniors make up 16.9 percent of the Canadian population. Furthermore, the number of Canadians who are 65 years or older is increasing at an average rate of 20 percent every 5 years. In 2017, Sing etal reported that there is an increasing number of patients undergoing degenerative scoliosis surgery with the largest increase attributed to patients aged 65–69 years followed by those aged 70–74 years. Therefore, the purpose of this study is to assess the effectiveness of undergoing spinal surgery to correct degenerative spinal scoliosis in the ever-growing number of elderly patients. We hypothesize that age is not an independent prognostic factor of patients' outcomes followings degenerative scoliosis surgery.

A retrospective review of prospectively collected data within the Canadian Spine Outcome and Research Network (CSORN) was conducted. Data was analyzed using IBM-SPSS. ANOVA was used to analyze continuous variables while Chi Square test was used to analyze categorical variables. Significance level was p < 0.05.

There were 165 patients identified from the registry who met the inclusion criteria, 94 patients (57 %) were female. There were 102 (61.8 %) patients who were 65 years or older. The overall average age was 66.6 years (range 35–84, SD 8.6). There were 27 intra-operative complications, 44 peri-operative complications and 18 post operative complications. There was no statistically significant difference between the two age groups with regards to risk of developing intra-operative, perioperative and post operative complications. Patients who underwent degenerative scoliosis surgery reported an average improvement of 2.95±3.32, 3.64±3.50, 16.84±20.44 points on the back-pain scale, leg pain scale and the Oswestry Disability Index (ODI) respectively, there was no statistically significant differences in these measures between the two age groups.

As the number of patients undergoing degenerative scoliosis surgery increases, clinicians will need to determine which factors will significantly impact patients' outcomes following surgery. This study shows that age is not an independent prognostic factor when it comes to patients' outcomes following degenerative scoliosis surgery. In the future, research should examine the impact of age in conjunction with factors such as frailty, comorbidities and functional status on patient outcomes.

K. Barton O. Hazenbiller M. Monument S. Puloski G. Freeman M. Ball A. Aboutaha

The burden of metastatic bone disease (MBD) in our Canadian cancer population continues to increase. MBD has a significant effect on patient morbidity, mortality, and health-related quality of life (HRQOL). There are various technical options used to surgically stabilize MBD lesions, surgical decision-making is variable and largely dependent on anatomic and surgeon-based factors. There is a paucity of research examining how surgical decision-making for MBD can be modified or individualized to improve quality of life (QOL) and functional outcomes, while more accurately aligning with patient-reported goals and expectations. The objective of this study was tosurvey MBD patients, support persons, physicians, and allied health care providers (HCP) with the goal of identifying 1) important contributors to HRQOL, 2) discordance in peri-operative expectations, and 3) perceived measures of success in the surgical management of MBD.

This project is a longitudinal patient-engaged research initiative in MBD. A survey was developed based on HRQOL themes in the literature and based on feedback from our patient research partners. Participants were asked to identify 1) important contributors to HRQOL and 2) perceived measures of success relevant to the surgical management of MBD. Participants were asked to rank themes from ‘extremely important’ to ‘not important at all’. Using open-ended questions, participants were asked to identify areas of improvement. Responses from the open-ended questions were analyzed by an experienced qualitative researcher using conventional content analysis. Participant's demographics were calculated using descriptive statistics. Concordance or discordance of perceived measure of success was assessed via a Chi-Square test of independence. All statistical analyses were performed using IBM SPSS® software.

Nine patients, seven support persons, 23 orthopaedic surgeons, 11 medical oncologists, 16 radiation oncologists, 16 nurses, and eight physiotherapists completed the survey. Regarding perceived measures of success, increased life expectancy (p Two main themes emerged around the timeliness of surgical care and the coordination of multidisciplinary care from patients and support persons. Patients and support persons expressed a sense of urgency in progressing to surgery/treatment, and frustration at perceived delays in treatment. Within coordination of care, patients and support persons would like clearer communication from the health care team.

There is discordance between patient/support person goals compared to physicians/HCP goals in the surgical management of MBD. Surgical decision-making and operative techniques that minimize disease progression and improve survival are important to MBD patients. Timely access to surgery/surgical consultation and improved multidisciplinary communication is important to patients. This data suggests improved peri-operative communication and education is needed for MBD patients. Furthermore, future research evaluating how modern orthopaedic surgical techniques influence survival and disease progression in MBD is highly relevant and important to patients with MBD.

K. Bali K. Smit P. Beaulé G. Wilkin S. Poitras M. Ibrahim

Hip dysplasia has traditionally been classified based on the lateral centre edge angle (LCEA). A recent meta-analysis demonstrated no definite consensus and a significant heterogeneity in LCEA values used in various studies to define hip dysplasia and borderline dysplasia. To overcome the shortcomings of classifying hip dysplasia based on just LCEA, a comprehensive classification for adult acetabular dysplasia (CCAD) was proposed to classify symptomatic hips into three discrete prototypical patterns of hip instability, lateral/global, anterior, or posterior. The purpose of this study was to assess the reliability of this recently published CCAD.

One thirty four consecutive hips that underwent a PAO were categorized using a validated software (Hip2Norm) into four categories of normal, lateral/global, anterior or psosterior. Based on the prevalence of individual dysplasia and using KappaSize R package version 1.1, seventy four cases were necessary for reliability analysis: 44 dysplastic and 30 normal hips were randomly selected. Six blinded fellowship trained raters were then provided with the classification system and they looked at the x-rays (74 images) at two separate time points (minimum two weeks apart) to classify the hips using standard PACS measurements. Thereafter, a consensus meeting was held where a simplified flow diagram was devised before a third reading by four raters using a separate set of 74 radiographs took place.

Intra-rater results per surgeon between Time 1 and Time 2 showed substantial to almost perfect agreement amongst the raters. With respect to inter-rater reliability, at time 1 and time 2, there was substantial agreement overall between all surgeons (kappa of 0.619 for time 1 and 0,623 for time 2). Posterior and anterior rating categories had moderate and fair agreement at time 1 and time 2, respectively. At time 3, overall reliability (kappa of 0.687) and posterior and anterior rating improved from Time 1 and Time 2.

The comprehensive classification system provides a reliable way to identify three categories of acetabular dysplasia that are well-aligned with surgical management. The term borderline dysplasia should no longer be used.

C. Chen Y. Tang H. Lu

An established rabbit model was used to preliminarily investigate the effect of acellular triphase, namely bone-cartilage-tendon, scaffold (ATS) sandwiched with autologous bone mesenchymal stem cells (BMSCs) sheets on tendon-bone interface healing. Bone, fibrocartilage and tendon tissue were harvested from the rabbits and sectioned into a book-type scaffold. The scaffolds were decellularized and their characterization was presented. BMSCs were isolated and co-cultured with the scaffolds to verify their cytocompatibility. BMSCs sheets were fabricated and inserted into the book page of the scaffold to construct an autologous BMSCs-sheets/book-type ATS complex. The complex was implated in the right knee of rabbits which operated standard partial patellectomy for TBI regeneration using Imaging, histological and biomechanical examinations.

The bone, fibrocartilage and tendon tissue were sectioned into a book-type scaffold before decellularization. Then we decellularized the above tissue and mostly preserved their microstructure and composition of the natural extracellular matrix, including collagen and proteoglycan. After the physicochemical and biological properties of the book-type ATS were evaluated, autologous BMSCs sheets were inserted into the book page of the scaffold to construct an autologous BMSCs-sheets/book-type ATS implants for TBI regeneration. In addition, the ATS has the advantages of non-toxicity, suitable for cell adhesion and growth as well as low immunogenicity while co-cultured with the BMSCs. At the same time, different scaffolds has the ability to induce the osteogenic, chondrogenic and tenogenic differentiation of BMSCs by immunofluorescence, reverse transcription-polymerase chain reaction and western blot analysis.

To determine the efficacy of the tissue-engineered implants for TBI regeneration, we transplanted it into a rabbit patella-patellar tendon (PPT) injury model, and the rabbits were sacrificed at postoperative week 8 or 16 for the radiological, histological, and mechanical evaluation. Radiologically, Synchrotron radiation micro-computed tomography (SR-μCT) showed that BMSCs/ATS group significantly increased bone area, BV/TV, trabecular thickness and trabecular number at the healing interface as compared with other groups at postoperative week 8 or 16. Histologically, the BMSCs/ATS group showed more woven bone, and a more robust fibrocartilaginous junction with a characteristic matrix rich in proteoglycans was seen at the PPT healing interface in comparison with other groups after 8 weeks. At week 16, the healing interface in 3 groups displayed better remodeling with respect to postoperative week 8. Healing and remodeling at the PPT junction were almost complete, with a resemblance to a healthy BTI consisting of the characteristic 4 zones in all groups. At last, we used biomechanical test as functional parameters to evaluate the quality of tendon-bone healing. Biomechanical testing indicated that BMSCs/ATS group showed significantly higher failure load and stiffness than other groups at postoperative week 8 and 16.

The complex composed of acellular triphase, namely bone-cartilage-tendon, scaffold (ATS) sandwiched with autologous bone mesenchymal stem cells (BMSCs) sheets can simulate the gradient structure of tendon-bone interface, inducing stem cell directional differentiation, so as to promote patella-patellar tendon interface healing effectively after injury.

J. Cornish M. Zhu S. Young D. Musson J. Munro

No animal model currently exists for hip abductor tendon tears. We aimed to 1. Develop a large animal model of delayed abductor tendon repair and 2. To compare the results of acute and delayed tendon repair using this model.

Fourteen adult Romney ewes underwent detachment of gluteus medius tendon using diathermy. The detached tendons were protected using silicone tubing. Relook was performed at six and 16 weeks following detachment, histological analysis of the muscle and tendon were performed. We then attempted repair of the tendon in six animals in the six weeks group and compared the results to four acute repairs (tendon detachment and repair performed at the same time). At 12 weeks, all animals were culled and the tendon–bone block taken for histological and mechanical analysis.

Histology grading using the modified Movin score confirmed similar tendon degenerative changes at both six and 16 weeks following detachment. Biomechanical testing demonstrated inferior mechanical properties in both the 6 and 16 weeks groups compared to healthy controls.

At 12 weeks post repair, the acute repair group had a lower Movin's score (6.9 vs 9.4, p=0.064), and better muscle coverage (79.4% of normal vs 59.8%). On mechanical testing, the acute group had a significantly improved Young's Modulus compared to the delayed repair model (57.5MPa vs 39.4MPa, p=0.032)

A six week delay between detachment and repair is sufficient to produce significant degenerative changes in the gluteus medius tendon. There are significant histological and mechanical differences in the acute and delayed repair groups at 12 weeks post op, suggesting that a delayed repair model should be used to study the clinical problem.

M. M. Innmann G. Grammatopoulos P. Beaulé C. Merle T. Gotterbarm

Spinopelvic mobility describes the change in lumbar lordosis and pelvic tilt from standing to sitting position. For 1° of posterior pelvic tilt, functional cup anteversion increases by 0.75° after total hip arthroplasty (THA). Thus, spinopelvic mobility is of high clinical relevance regarding the risk of implant impingement and dislocation.

Our study aimed to 1) determine the proportion of OA-patients with stiff, normal or hypermobile spino-pelvic mobility and 2) to identify clinical or static standing radiographic parameters predicting spinopelvic mobility.

This prospective diagnostic cohort study followed 122 consecutive patients with end-stage osteoarthritis awaiting THA. Preoperatively, the Oxford Hip Score, Oswestry Disability Index and Schober's test were assessed in a standardized clinical examination. Lateral view radiographs were taken of the lumbar spine, pelvis and proximal femur using EOS© in standing position and with femurs parallel to the floor in order to achieve a 90°-seated position. Radiographic measurements were performed for the lumbar lordosis angle (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI) and pelvic-femoral-angle (PFA). The difference in PT between standing and seated allowed for patient classification based on spino-pelvic mobility into stiff (±30°).

From the standing to the sitting position, the pelvis tilted backwards by a mean of 19.6° (SD 11.6) and the hip was flexed by a mean of 57° (SD 17). Change in pelvic tilt correlated inversely with change in hip flexion.

Spinopelvic mobility is highly variable in patients awaiting THA and we could not identify any clinical or static standing radiographic parameter predicting the change in pelvic tilt from standing to sitting position. In order to identify patients with stiff or hypermobile spinopelvic mobility, we recommend performing lateral view radiographs of the lumbar spine, pelvis and proximal femur in all patients awaiting THA. Thereafter, implants and combined cup inclination/anteversion can be individually chosen to minimize the risk of dislocation.

No predictors could be identified. We recommend performing sitting and standing lateral view radiographs of the lumbar spine and pelvis to determine spinopelvic mobility in patients awaiting THA.

R. R. Akhtar J. Khan R. Ahmed

To determine the number of patients with low back pain who have low serum Vitamin-D levels in our local population and the clinical efficacy of Vitamin-D supplementation on VAS and MODQ scores

This Prospective cohort study was conducted from 20th March 2016 to 19th March 2017. 600 patients were included in the study who met the inclusion criteria, i.e. patients presenting to the Out Patient Department (OPD) with low back pain for a duration of less than six months aged between 15 to 55 years. Venous blood withdrawn and serum levels of Vitamin-D measured. According to serum Vitamin-D levels, categorized as deficient, sufficient or excess. Those having deficient Vitamin-D levels (< 2 0 ng/dL) were given Vitamin-D supplementation as Oral 50,000 IU Vitamin-D3 daily for 05 days, then once weekly for 08 weeks while those having insufficient levels (20–30 ng/dL) given Oral 50,000 IU Vitamin-D3 once weekly for 08 weeks. Vitamin-D levels, Visual Analog Pain Scale (VAS) and Modified Oswestry Disability Questionnaire (MODQ) scoring done at baseline, 02, 03 and 06 months. Data analyzed using SPSS version 23.

Mean age of patients included in the study 44.21 ± 11.92 years. Out of the total, 337 (56.17%) were males and 263 (43.83%) females. Out of the total, 20.67%, 26.17% and 28.83% had mild, moderate and severe Vitamin-D deficiency, respectively. Predominantly patients with severe Vitamin-D deficiency presented in winters (October – February) (17.16%) as compared to other seasons. The most pre-dominant risk factor in patients with low Vitamin-D levels was smoking (21.33%). Mean baseline Vitamin-D levels were 13.32 ± 6.10 ng/dL and after supplementation these levels improved to 37.18 ± 11.72 ng/dL. VAS score improved from a mean baseline value to 81 to 36 at 6 months (p < 0 .01). Likewise, MODQ score decreased from a baseline mean of 46 to 25 at 6 months (p < 0 .01)

Vitamin D plays a crucial role in the musculoskeletal framework of the body. The deficiency is more prevalent in the youth due to sedentary lifestyle and indoor preference. Improvement in pain & functional disability with Vitamin-D supplementation

For any reader queries, please contact virgo_r24@hotmail.com

R. R. Akhtar J. Khan

To compare the efficacy of local steroid injection with surgical decompression in treatment of carpal tunnel syndrome (CTS) in terms of frequency of pain.

This randomized controlled study was conducted at the Department of Orthopaedics for a duration of 01 year, i.e. from 20th April 2016 to 19th April 2017. 130 patients with carpal tunnel syndrome with moderate (Grade 2) and severe (Grade 3) pain were included. Lottery method was used to allocate the patients randomly into two groups. Group A contained 65 patients who were subjected to surgical decompression and 65 patients were in Group B who were injected with local steroid injection. Complete history was obtained from all patients. All the surgical decompressions through mini incision technique and injections procedures were performed. Information were recorded in a pre designed Performa.

Efficacy was observed significantly high in group B as compared to group A (87.7% vs. 72.3%, p=0.028).

Carpal Tunnel syndrome symptoms were alleviated with surgical decompression as well as local steroid injection at a follow up done after 1 month. However the steroid injections seem to have greater efficacy than surgical decompression, hence we suggest it for routine treatment of all patients with CTS.

For any reader queries, please contact virgo_r24@hotmail.com

J. Costi C. Moawad D. Amin

Repetitive manual handling caused 31% of all work related musculoskeletal disorders in 2015, with the back being the site of injury 38% of the time. Despite its high resilience, studies have shown that intervertebral discs can be damaged during repetitive loading at physiological motions, causing cumulative damage and disc herniation. To understand the mechanism of disc injury resulting from repetitive lifting, it is important to measure disc deformations/strains accompanied by MRI imaging to identify disc tissue damage. Therefore, the aim of this study was to examine associations between the magnitude of 3D internal strains, tissue damage and macroscopic evidence of disc injury after simulated repetitive lifting on normal human lumbar discs.

Sixteen cadaver lumbar functional spinal units (FSUs) were subjected to pre-test MRI. Eight FSUs (control) underwent 20,000 cycles or until failure (5 mm displacement) of loading under compression (1.7 MPa – to simulate lifting a 20 kg weight) + flexion (13°) + right axial rotation (2°) using a novel Hexapod Robot. The remaining eight FSUs (experimental) had a grid of tantalum wires inserted, and stereoradiographs were taken to track internal disc displacements at increasing cyclic intervals. Maximum shear strains (MSS) were calculated from the displacements using radiostereometric analysis at cycle 1 and 20,000 cycles (or failure). Post-test MRI was conducted to determine the extent of tissue damage and associated with regions of highest MSS. A repeated measures ANOVA was performed on MSS with a within–subjects factor of cycle number (cycle 1 and failure cycle) and a between subjects-factor of disc region and failure type (p < 0 .05).

Pfirrmann grading revealed mostly normal discs [I (N=2), II (N=13), and III (N=1)]. No significant difference in MSS between control and experimental groups was found for number of cycles to failure (p=0.279). Pre and post-test MRI analysis revealed that 13 specimens were injured after repetitive lifting with either an endplate failure (N=9) or disc bulge (N=4), and two specimens did not fail. Failure strain was significantly greater than cycle 1 in all regions except posterior, left/right posterolateral (p>0.109). Largest MSS at failure was seen in the anterior (60%), and left/right posterolateral regions (64% and 70%, respectively). MSS at failure for the endplate failure group was significantly larger than the no injury group in all regions except right lateral and nucleus (p>0.707). Disc bulge group MSS was significantly larger than the no injury group in the anterior, right anterolateral, and left/right posterolateral regions (p < 0 .027).

Simulated repetitive lifting led to largest shear strains in the anterior, left and right posterolateral regions that corresponded to annular tears or annular protrusion. The no injury group shear strain was less than 50% in all regions, indicating there may be a threshold that could be associated with tissue damage linked with injuries such as disc bulge and endplate failure. There was no evidence of disc herniation in normal discs, agreeing with current clinical knowledge. These results may be indicative of the effects of repetitive manual handling on normal discs of younger patients.

J. Khan R. Ahmed

To determine the effect of Dexamethasone on post-operative pain management in patients undergoing Total Knee Arthroplasty in terms of numerical pain rating scale and total opoid consumption.

This Randomized Controlled Trail (RCT) was conducted for 02 years (7th September 2015 to 6th September 2017). All patients undergoing primary Unilateral Total Knee Replacement (TKR) for Osteoarthritis knee were included in the study. Patients with poor glycemic control (HbA1c > 7.6), Hepatic/Renal failure, corticosteroids/ Immunosuppression drug usage in the last 06 months, known psychiatric illnesses were excluded from the study. All patients were operated by consultant Orthopaedic surgeon under Spinal Anaesthesia and tourniquet control using medial para-patellar approach. Patients were randomly divided into 02 groups, A and B. 79 patients were placed in each group. Group A given 0.1mg/kg body weight Dexamethasone Intravenously 15 minutes prior to surgery and another dose 24 hours post-operatively while in group B (control group) no Dexamethasone given. Post-operative pain using the numerical pain rating scale (NRS) and total narcotics consumed converted to morphine dose equivalent noted immediately post-op, 12-, 24- and 48-hours post-operatively. Data analysis done using SPSS version 23.

A total of 158 patients were included in the study. Of the total, 98 (62.02%) were females and 60 (37.98%) males. Average BMI of patients 26.94 ±3.14 kg/m2. Patients in group A required less post-operative analgesics (p < 0 .01) and had a better numerical pain rating scale score (p < 0 .01) as compared to group B. Pain scores at 24- and 48-hours post-op were significantly less for Dexamethasone group (p < 0 .01).

Use of Dexamethasone per- and post-operatively reduces the pain and amount of analgesics used in patients undergoing TKA.

For any reader queries, please contact drjunaidrmc@gmail.com

P. K. Chan C. H. Yan K. Y. Chiu

In total knee arthroplasty (TKA), both intravenous (IV) and/or intra-articular (IA) administration of tranexamic acid (TXA) were showed to reduce blood loss. Moreover, research suggesting TXA decreases postoperative knee swelling, but it is unknown whether this results in improved postoperative rehabilitation outcome. Thus, the aim of this study was to evaluate whether combined IV and IA administration of TXA would associate with improved early rehabilitation outcomes.

In this institutional review board approved randomized controlled trial, 179 patients scheduled for unilateral TKA were randomized to one of three regimens: (1) IA administration of 1gm TXA at end of procedure only, (2) additional preoperative IV dose of 15 mg/kg 30min before tourniquet inflation, and (3) additional postoperative dose 4hrs after preoperative dose. Primary outcomes included knee range of motion, Knee Society Score (KSS) at 6-month postoperatively, haemoglobin drop at day-2 post-operatively, and transfusion rate. Secondary outcome was venous thromboembolism (VTE) complications.

Baseline characteristics were comparable between the allocation groups. Patients in regimen (3) showed statistically significant better knee extension range (6.2°, 5.9°, 2.9°, p=0.01), and KSS (88.5, 89.9, 93.0, p=0.02) at 6-month postoperatively, and lesser drop in haemoglobin at day-2 post-operatively (2.72, 2.47, 1.75 g/dL, p=0) when compared with patients in other regimens. No patients required transfusion, or complicated by VTE.

The combined administration of IA and IV TXA, including both preoperative and postoperative doses, associated with statistically significantly improved early rehabilitation outcomes. The improvement may be related to higher haemoglobin level and decreased knee swelling in patients having regimen (3).

For any reader queries, please contact cpk464@yahoo.com.hk

J. Khan R. R. Akhtar R. Ahmed

To compare the efficacy of intra-articular and intravenous modes of administration of tranexamic acid in primary Total Knee Arthroplasty in terms of blood loss and fall in haemoglobin level.

This randomized controlled trial was conducted from 12th May 2017 to 11th May 2017. Seventy eight patients were included in the study. Patients were randomly divided into group A and B. Group A patients undergoing unilateral primary total knee replacement (TKR) were given intravenous tranexamic acid (TXA) while group B were infiltrated with intra-articular TXA. Volume of drain output, fall in haemoglobin (Hb) level and need for blood transfusion were measured immediately after surgery and at 12 and 24 hours post operatively in both groups.

The study included 35 (44.87%) male and 43 (55.13%) female patients. Mean age of patients was 61±6.59 years. The mean drain output calculated immediately after surgery in group A was 45.38±20.75 mL compared with 47.95±23.86 mL in group B (p=0.73). 24 hours post operatively, mean drain output was 263.21±38.50 mL in intravenous group versus 243.59±70.73 mL in intra-articular group (p=0.46). Regarding fall in Hb level, both groups showed no significant difference (p>0.05). 12.82% (n=5) patients in group A compared to 10.26% (n=4) patients required blood transfusion post operatively (p=0.72).

Intra-articular and intravenous TXA are equally effective in patients undergoing primary total knee arthroplasty in reducing post operative blood loss.

For any reader queries, please contact drjunaidrmc@gmail.com

C. Conlin D. Ogilvie-Harris L. Phillips L. Murnaghan J. S. Theodoropoulos N. Matthies

The purpose of this study was to determine whether the reasons for delay to surgery are secondary to health system constraints or patient factors. This study explored factors that contribute to patients' delay to surgery as well as how patients perceive the delay in surgery to have affected their treatment and care.

Semi-structured qualitative interviews were conducted with 30 patients aged 18 to 50 years old who had undergone arthroscopic ACL reconstruction. Qualitative data analysis was performed in accordance with the Straus and Corbin theory to derive codes, categories and themes.

Patient interviews revealed three overarching themes regarding delay to ACL reconstruction surgery: access to care, finances and work, and personal advocacy. Elements of those factors were shown to influence the timing of ACL reconstruction surgery. Less common factors included choice of imaging study (i.e., ultrasound), geography, and family commitments.

Patients' perceptions of delay in access to care was overwhelming due to the wait time for MRI. Several patients also described significant self-advocacy required to navigate the healthcare system, suggesting that some level of medical literacy may be necessary to gain timely access to surgery. Once patients had seen the surgeon, few patients described untimely delay to surgery, suggesting that OR resources are adequate. Recommendations to decrease delays to ACL reconstruction surgery include better access to MRI and broader education of non-surgical healthcare providers to help navigate access to surgery.

S. Undurraga K. Au A. Salimian B. Gammon

Longstanding un-united scaphoid fractures or scapholunate insufficiency can progress to degenerative wrist osteoarthritis (termed scaphoid non-union advanced collapse (SNAC) or scapho-lunate advanced collapse (SLAC) respectively). Scaphoid excision and partial wrist fusion is a well-established procedure for the surgical treatment of this condition. In this study we present a novel technique and mid-term results, where fusion is reserved for the luno-capitate and triquetro-hamate joints, commonly referred to as bicolumnar fusion. The purpose of this study was to report functional and radiological outcomes in a series of patients who underwent this surgical technique.

This was a prospective study of 23 consecutive patients (25 wrists) who underwent a bicolumnar carpal fusion from January 2014 to January 2017 due to a stage 2 or 3 SNAC/SLAC wrist, with a minimum follow-up of one year. In all cases two retrograde cannulated headless compression screws were used for inter-carpal fixation. The clinical assessment consisted of range of motion, grip and pinch strength that were compared with the unaffected contralateral side where possible. Patient-reported outcome measures, including the DASH and PRWE scores were analysed. The radiographic assessment parameters consisted of fusion state and the appearance of the radio-lunate joint space. We also examined the relationship between the capito-lunate fusion angle and wrist range of motion, comparing wrists fused with a capito-lunate angle greater than 20° of extension with wrists fused in a neutral position.

The average follow-up was 2.9 years. The mean wrist extension was 41°, flexion 36° and radial-ulnar deviation arc was 43° (70%, 52% and 63% of contralateral side respectively). Grip strength was 40 kg and pinch strength was 8.9 kg, both 93% of contralateral side. Residual pain for activities of daily living was 1.4 (VAS). The mean DASH and PRWE scores were 19±16 and 29±18 respectively. There were three cases of non-union (fusion rate of 88%). Two wrists were converted to total wrist arthroplasty and one partial fusion was revised and healed successfully. Patients with an extended capito-lunate fusion angle trended toward more wrist extension but this did not reach statistical significance (P= 0.07). Wrist flexion did not differ between groups. Radio-lunate joint space narrowing progressed in 2 patients but did not affect their functional outcome.

After bicolumnar carpal fusion using retrograde headless screws, patients in this series maintained a functional flexion-extension arc of motion, with grip-pinch strength that was close to normal. These functional outcomes and fusion rates were comparable with standard 4-corner fusion technique. A capito-lunate fusion angle greater than 20° may provide more wrist extension but further investigation is required to establish this effect. This technique has the advantage that compression screws are placed in a retrograde fashion, which does not violate the proximal articular surface of the lunate, preserving the residual load-bearing articulation. Moreover, the hardware is completely contained, with no revision surgery for hardware removal required in this series.

S. Carsen M. Doyle K. Smit A. Shefrin T. Varshney

The “Toddler Fracture” is an un-displaced oblique distal tibia fracture seen in children 9–36months of age presenting with refusal to walk, often after an unwitnessed or minor injury. Diagnosis is often made clinically, because initial x-rays are negative in up to 50% of patients, and then confirmed by the presence of periosteal reaction on follow up x-ray 7–10 days later. Point of Care Ultrasound (POCUS) has shown excellent ability to detect distal radius, clavicle and other extremity fractures and published case reports suggest that POCUS can also detect Toddler Fractures. The objective of this proof of concept study was to establish the feasibility and preliminary sensitivity and specificity of POCUS in the diagnosis of Toddler Fractures, and to characterize the POCUS findings in patients presenting with clinical Toddler Fractures.

This was a prospective reviewer-blinded cross-sectional study of patients presenting to the emergency department of a paediatric tertiary care centre with presumed toddler fractures. All patients with suspected toddler fracture underwent lower limb x-ray. Those enrolled in the study also underwent POCUS of both lower extremities by a specialized provider. Treating clinicians were blinded to ultrasound results, and study sonographers were blinded to x-ray results. Study patients were then seen in paediatric orthopaedic follow up clinics 7–10 days later, and clinical assessment and follow up x-ray were performed as necessary to confirm diagnosis.

Toddler Fracture was confirmed in 5 of 27 patients enrolled in the study. Preliminary results demonstrate that these POCUS findings were detected on the scan in all 5 confirmed toddler fractures. Three of these patients had an initial positive x-ray and 2 went on to have toddler fracture confirmed on follow up x-ray and orthopaedic assessment. POCUS findings consistent with a toddler fracture were found to be cortical disruption and periosteal hematoma.

POCUS may be a useful adjunct to confirming a diagnosis of a toddler fracture when clinical suspicion is high and initial x-ray is negative. This pilot study provides positive impetus for further prospective study. The use of POCUS to confirm toddler fracture can decrease further radiation exposure to patients, allow early guidance to families on the management and expected recovery, and has potential to decrease burden on families and the healthcare system by potentially eliminating unnecessary follow-up appointments. Future study will help to better guide diagnostic and technical criteria, and provide guidance for appropriate medical education in this technique and interpretation.

A. Bozzo M. Ghert

Advances in cancer therapy have prolonged cancer patient survival even in the presence of disseminated disease and an increasing number of cancer patients are living with metastatic bone disease (MBD). The proximal femur is the most common long bone involved in MBD and pathologic fractures of the femur are associated with significant morbidity, mortality and loss of quality of life (QoL).

Successful prophylactic surgery for an impending fracture of the proximal femur has been shown in multiple cohort studies to result in patients more likely to walk after surgery, longer survival, lower transfusion rates and shorter post-operative hospital stays. However, there is currently no optimal method to predict a pathologic fracture. The most well-known tool is Mirel's criteria, established in 1989 and is limited from guiding clinical practice due to poor specificity and sensitivity. The goal of our study is to train a convolutional neural network (CNN) to predict fracture risk when metastatic bone disease is present in the proximal femur.

Our fracture risk prediction tool was developed by analysis of prospectively collected data for MBD patients (2009–2016) in order to determine which features are most commonly associated with fracture. Patients with primary bone tumors, pathologic fractures at initial presentation, and hematologic malignancies were excluded. A total of 1146 patients comprising 224 pathologic fractures were included. Every patient had at least one Anterior-Posterior X-ray. The clinical data includes patient demographics, tumor biology, all previous radiation and chemotherapy received, multiple pain and function scores, medications and time to fracture or time to death. Each of Mirel's criteria has been further subdivided and recorded for each lesion.

We have trained a convolutional neural network (CNN) with X-ray images of 1146 patients with metastatic bone disease of the proximal femur. The digital X-ray data is converted into a matrix representing the color information at each pixel. Our CNN contains five convolutional layers, a fully connected layers of 512 units and a final output layer. As the information passes through successive levels of the network, higher level features are abstracted from the data. This model converges on two fully connected deep neural network layers that output the fracture risk. This prediction is compared to the true outcome, and any errors are back-propagated through the network to accordingly adjust the weights between connections. Methods to improve learning included using stochastic gradient descent with a learning rate of 0.01 and a momentum rate of 0.9.

We used average classification accuracy and the average F1 score across test sets to measure model performance. We compute F1 = 2 x (precision x recall)/(precision + recall). F1 is a measure of a test's accuracy in binary classification, in our case, whether a lesion would result in pathologic fracture or not. Five-fold cross validation testing of our fully trained model revealed accurate classification for 88.2% of patients with metastatic bone disease of the proximal femur. The F1 statistic is 0.87. This represents a 24% error reduction from using Mirel's criteria alone to classify the risk of fracture in this cohort.

This is the first reported application of convolutional neural networks, a machine learning algorithm, to an important Orthopaedic problem. Our neural network model was able to achieve impressive accuracy in classifying fracture risk of metastatic proximal femur lesions from analysis of X-rays and clinical information. Our future work will aim to validate this algorithm on an external cohort.

S. Khan D. Wasserstein D. J. G. Stephen P. Henry M. Catapano R. Paul

Acute metatarsal fractures are a common extremity injury. While surgery may be recommended to reduce the risk of nonunion or symptomatic malunion, most fractures are treated with nonoperative management. However, there is significant variability between practitioners with no consensus among clinicians on the most effective nonoperative protocol, despite how common the form of treatment. This systematic review identified published conservative treatment modalities for acute metatarsal fractures and compares their non-union rate, chronic pain, and length of recovery, with the objective of identifying a best-practices algorithm.

Searches of CINAHL, EMBASE, MEDLINE, and CENTRAL identified clinical studies, level IV or greater in LOE, addressing non-operative management strategies for metatarsal fractures. Two reviewers independently screened the titles, abstracts, and full texts, extracting data from eligible studies. Reported outcome measures and complications were descriptively analyzed. Studies were excluded if a rehabilitation program outlining length of immobilization, weight-bearing and/or strengthening approaches was not reported.

A total of 12 studies (8 RCTs and 4 PCs), from the 2411 studies that were eligible for title screening, satisfied inclusion criteria. They comprised a total of 610 patients with acute metatarsal fractures, with a mean age of 40.2 years (range, 15 – 82). There were 6 studies that investigated avulsion fractures, 2 studies on true Jones fractures, and 4 studies with mixed fracture types. Studies assessed a variety of treatment modalities including: WB and NWB casts, elasticated support bandages, hard-sole shoes, plaster slippers, metatarsal shoe casts, and air cast boots. Most studies investigated the outcomes of NWB casts and elasticated support bandages.

The NWB short leg cast had no reported non-unions, delayed-unions, or refractures for avulsion fractures. In true Jones fractures, there was an average non-union rate of 23.6% (range, 5.6 – 27.8%), delayed-union rate of 11.8% (range, 5.6 – 18.8%), and refracture rate of 3% (range, 0 – 5.6%). Overall, the average AOFAS score was 87.2 (range, 84 – 91.7) and the average VAS score was 83.7 (range, 75 – 93).

The elasticated support bandage had an average non-union rate of 3.4% (range, 0 – 12%), and delayed-union rate of 3.8% for acute avulsion fractures, with no reported refractures. No included study arm investigated outcomes of elasticated support bandages for the true Jones fracture. The average AOFAS score for elasticated support bandages was 93.5 (range, 90 – 100). The average VAS score was 88.9 (range, 90 – 100).

Most acute metatarsal fractures heal well, with good-to-excellent functional outcomes and moderate-to-high patient satisfaction. Conservative strategies for avulsion fractures are highly successful and based on this data the authors recommend patients undergo a schedule that involves 3 – 4 weeks in an elasticated support bandage, short leg cast, or equivalent, and WB thereafter as tolerated, with return-to-activity after clinical union. Despite poorer conservative outcomes for true Jones fractures, patients should undergo 8 weeks in a NWB short leg cast, followed by a walking cast or hard-sole shoe for an additional 4 – 6 weeks, or until clinical union. However, surgical consultation is recommended.

A. Bozzo A. Adili K. Madden

Total hip arthroplasty (THA) is one of the most successful and effective treatments for advanced hip osteoarthritis (OA). Over the last 5 years, Canada has seen a 17.8% increase in the number of hip replacements performed annually, and that number is expected to grow along with the aging Canadian population. However, the rise in THA surgery is associated with an increased number of patients at risk for the development of an infection involving the joint prosthesis and adjacent deep tissue – periprosthetic joint infections (PJI). Despite improved hygiene protocols and novel surgical strategies, PJI remains a serious complication. No previous population-based studies has investigated PJI risk factors using a time-to-event approach and none have focused exclusively on patients undergoing THA for primary hip OA. The purpose of this study is to determine risk factors for PJI after primary THA for OA using a large population-based database collected over 15 years. Our secondary objective is to determine the incidence of PJI, the time to PJI following primary THA, and if PJI rates have changed in the past 15 years.

We performed a population-based cohort study using linked administrative databases in Ontario, Canada in accordance with RECORD and STROBE guidelines. All primary total hip replacements performed for osteoarthritis in patients aged 55 or older between January 1st 2002 – December 31st 2016 in Ontario, Canada were identified. Periprosthetic joint infection as the cause for revision surgery was identified with the International Classification of Diseases, 10th Edition (ICD-10), Clinical Modification diagnosis code T84.53 in any component of the healthcare data set.

Data were obtained from the Institute for Clinical Evaluative Sciences (ICES).

Demographic data and outcomes are summarized using descriptive statistics. We used a Cox proportional hazards model to analyze the effect of surgical factors and patient factors on the risk of developing PJI. Surgical factors include the approach, use of bone graft, use of cement, and the year of surgery. Patient factors include sex, age at surgery, income quintile and rurality (community vs. urban). We compared the 1,2,5 and 10 year PJI rates for patients undergoing THA each year of our cohort with the Cochran-Armitage test. Less than 0.1% of data were missing from all fields except for rurality which was lacking 0.3% of data.

A total of 100,674 patients aged 55 or older received a primary total hip arthroplasty for osteoarthritis from 2002–2016. We identified 1034 cases of revision surgery for prosthetic joint infection for an overall PJI rate of 1.03%. When accounting for patients censored at final follow-up, the cumulative incidence for PJI is 1.44%. Our Cox proportional hazards model revealed that male sex, Type II diabetes mellitus, discharge to convalescent care, and having both hips replaced during one's lifetime were associated with increased risk of developing PJI following primary THA. Importantly, the time adjusted risk for PJI was equal for patients operated within the past 5 years, 6–10 years ago, or 11–15 years ago. The surgical approach, use of bone grafting or cement were not associated with increased risk of infection. PJI rates have not changed significantly over the past 15 years. One, two, five and ten-year PJI rates were similar for patients undergoing THA in all qualifying years.

Analysis of a population-based cohort of 100,674 patients has shown that the risk of developing PJI following primary THA has not changed over 15 years. The surgical approach, use of bone grafting or cement were not associated with increased risk of infection. Male sex, Type II diabetes Mellitus and discharge to a rehab facility are associated with increased risk of PJI. As the risk of PJI has not changed in 15 years, an appropriately powered trial is warranted to determine interventions that can improve infection rate after THA.

A. Bin Shabib F. Al-Jahdali W. Aljuhani B. Ahmed M. Salam

Surgical biopsies are still considered the gold standard in obtaining tumor tissue samples. In this study, we will analyze the core needle biopsy in the evaluation of musculoskeletal tumors focusing on the accuracy, effectiveness, and safety of this technique in comparison to an open biopsy procedure.

This is a retrospective case series at King Abdulaziz Medical City (KAMC). All medical records from all patients who had a core needle biopsy (CNB) for a musculoskeletal mass and eventually underwent excisional biopsy between January 2010 and December 2016 at KAMC were included. Besides patient demographic data, the data extracted included the locations of the suspected mass, type of tissue acquired (bone or soft tissue), number of biopsies, complications reported during the procedure, histopathological report of core needle biopsy.

A total of 262 patients who were suspected to have a musculoskeletal tumor were identified. Female to male ratio was (1:1.4) and paediatrics (of 93.1%. The AUC of CNB in comparison to excisional biopsy was 0.86. The most common site of tumor extraction was in lower extremities (47.3%), followed by upper extremities (23.7%), pelvis and gluteal area (19.5%) and spine (9.5%).

In conclusion, CNB is cost-effective, safe and minimally invasive in bony and soft tissue lesions in comparison to an open biopsy procedure. Therefore, initiatives are required to implement this procedure to the majority of health care centers.

K. Vu P. Phan A. Stratton S. Kingwell M. Hoda E. Wai

Resident involvement in the operating room is a vital component of their medical education. Conflicting and limited research exists regarding the effects of surgical resident participation on spine surgery patient outcomes. Our objective was to determine the effect of resident involvement on surgery duration, length of hospital stay and 30-day post-operative complication rates.

This study was a multicenter retrospective analysis of the prospectively collected American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database. All anterior cervical or posterior lumbar fusion surgery patients were identified. Patients who had missing trainee involvement information, surgery for cancer, preoperative infection or dirty wound classification, spine fractures, traumatic spinal cord injury, intradural surgery, thoracic surgery and emergency surgery were excluded. Propensity score for risk of any complication was calculated to account for baseline characteristic differences between the attending alone and trainee present group. Multivariate logistic regression was used to investigate the impact of resident involvement on surgery duration, length of hospital stay and 30 day post-operative complication rates.

1441 patients met the inclusion criteria: 1142 patients had surgeries with an attending physician alone and 299 patients had surgeries with trainee involvement. After adjusting using the calculated propensity score, the multivariate analysis demonstrated that there was no significant difference in any complication rates between surgeries involving trainees compared to surgeries with attending surgeons alone. Surgery times were found to be significantly longer for surgeries involving trainees. To further explore this relationship, separate analyses were performed for tertile of predicted surgery duration, cervical or lumbar surgery, instrumentation, inpatient or outpatient surgery. The effect of trainee involvement on increasing surgery time remained significant for medium predicted surgery duration, longer predicted surgery duration, cervical surgery, lumbar surgery, lumbar fusion surgery and inpatient surgery. There were no significant differences reported for any other factors.

After adjusting for confounding, we demonstrated in a national database that resident involvement in surgeries did not increase complication rates, length of hospital stay or surgical duration of more routine surgical cases. We found that resident involvement in surgical cases that were generally more complexed resulted in increased surgery time. Further study is required to determine the relationship between surgery complexity and the effect of resident involvement on surgery duration.

E. Akoury P. Ahangar A. Sofia R. Luna A. Nour M. Weber D. Rosenzweig

The spine is one of the most common sites of bony metastasis, with 80% of prostate, lung, and breast cancers metastasizing to the vertebrae resulting in significant morbidity. Current treatment modalities are systemic chemotherapy, such as Doxorubicin (Dox), administered after resection to prevent cancer recurrence, and systemic antiresorptive medication, such as Zolendronate (Zol), to prevent tumor-induced bone destruction. The large systemic doses required to elicit an adequate effect in the spine often leads to significant side-effects by both drugs, limiting their prolonged use and effectiveness. Recently published work by our lab has shown that biocompatible 3D-printed porous polymer scaffolds are an effective way of delivering Dox locally over a sustained period while inhibiting tumor growth in vitro. Our lab has also generated promising results regarding antitumor properties of Zol in vitro. We aim to develop 3D-printed scaffolds to deliver a combination of Zol and Dox that can potentially allow for a synergistic antitumor activity while preventing concurrent bone loss locally at the site of a tumor, avoiding long systemic exposure to these drugs and decreasing side effects in the clinical setting.

The PORO Lay polymer filaments are 3D-printed into 5mm diameter disks, washed with deionized water and loaded with Dox or Zol in aqueous buffer over 7 days. Dox or Zol-containing supernatant was collected daily and the drug release was analyzed over time in a fluorescence plate reader. The polymer-drug (Dox or Zol) release was tested in vitro on prostate and lung cancer cell lines and on prostate- or lung-induced bone metastases cells. Alternatively, direct drug treatment was also carried out on the same cells in vitro. Following treatment, all cells were subject to proliferation assay (MTT and alamar blue), viability assay (LIVE/DEAD), migration assay (Boyden chamber) and invasion assay (3D gel matrix). 3D-printed scaffolds loaded with both Dox and Zol will also be tested on cells.

We have established an effective dose (EC50) for prostate and lung cancer cell lines and bone metastases cells with direct treatment with Zol or Dox. We have titrated the drug loading of scaffolds to allow for a release amount of Dox at the EC50 dose over 7 days. In ongoing experiments, we are testing the release of Zol. We have shown Dox releasing scaffolds inhibit cancer cell growth in a 2D culture over 7 days using the above cellular assays and testing the scaffolds with Zol is currently being analyzed.

3D-printed porous polymers like the PORO Lay series of products offer a novel and versatile opportunity for delivery of drugs in future clinical settings. They can decrease systemic exposure of drugs while at the same time concentrating the drugs effect at the site of tumors and consequently inhibit tumor proliferation. Their ability to be loaded with multiple drugs can allow for achieving multiple goals while taking advantage of synergistic effects of different drugs. The ability to 3D-print these polymers can allow for production of custom implants that offer better structural support for bone growth.

D. Castano G. Grammatopoulos A. Salimian P. Beaulé

During a periacetabular osteotomy (PAO), intra-operative assessment of correction of acetabular parameters is typically performed using fluoroscopy of the hip, a technique that has not been shown to produce predictable measurements. Furthermore, paralysing agents are used in order to facilitate dissection and fragment mobilization. The effect of paralysing agents on spino-pelvic posture is yet to be investigated.

This study aims to: 1. Compare the reliability of intra-operative x-rays versus hip fluoroscopy in the assessment of acetabular fragment correction and 2. Evaluate the effect of changes in spino-pelvic alignment on the assessment of acetabular correction. An IRB approved, retrospective review of all patients who underwent a PAO at our institution between 2006–2018 was performed. Patient demographic data was collected and all available imaging studies were retrieved. Patients were excluded if there was no available to review intra-operative AP pelvis x-ray or intra-operative fluoroscopic PA image of the hip.

Using a validated hip analysis software (Hip2Norm), the lateral center edge angle (LCEA) and acetabular index (AI) of plain radiographs were measured. The sacro-femoral-pubic angle (SFP), along with the LCEA and AI of the fluoroscopic image were measured using ImageJ. A oneway ANOVA was used to detect differences between measured parameters in the intra-operative x-ray, the post-operative x-ray and the fluoroscopic image. A total of 93 patients were identified. 26 patients were excluded due to missing data. The mean LCEA in the post-operative, intra-operative, and fluoroscopic groups were as follows: 33.67° (range 5.3° to 52.4°), 30.71°(range 9° to 55.6°), and 29.23°(range 12.4° to 51.4°) respectively. The mean AI in the post-operative, intra-operative, and fluoroscopic groups were as follows: −0.65° (range −18.10° to 27.30°), 0.35°(range −16.10° to 17.20°), and 5.54°(range −11.66° to 27.83°) respectively.

When comparing intra-operative to post-operative plain radiographs, there was no statistically significant difference in AI (ΔAI −1±1.29° p=0.71) or LCEA (ΔLCEA 2.95±1.38° p=0.09). When comparing fluoroscopy to post-operative plain radiographs, there was a statistically significant difference in AI (ΔAI −6.21±1.29° p < 0 .0001) as well as LCEA (ΔLCEA 4.44±1.38° p < 0 .0001). Statistical analysis revealed no influence of demographics (age, BMI, gender), on acetabular correction parameters. The mean SPF angles measured from intra-operative and post-operative x-rays were 69.32±5.11° and 70.45±5.52°. There was a statistically significant difference between these 2 measurements with a ΔSFP of 1.03° (p < 0 .0001).

The results of our study show that the use of intra-operative x-ray for the assessment of LCEA and AI is more reliable than fluoroscopic images. Further, we found a difference in SFP angle, which offers an indirect assessment of pelvic tilt, between the intra-operative and the post-operative plain x-rays. This suggests that there are changes in pelvic tilt during the surgery, which can be attributed to either patient positioning or changes in spino-pelvic posture secondary to the paralysing agents used by the anesthetists. The use of intra-operative x-rays as well as the effect of paralysing agents on spino-pelvic alignment should be considered by surgeons performing PAO's.

U. Sheth P. Nelson C. Kwan V. Tjong M. Terry

Traditionally, open reduction and internal fixation (ORIF) and hemiarthroplasty (HA) have been the surgical treatments of choice for displaced proximal humerus fractures (PHF) despite high rates of fixation failure and tuberosity nonunion, especially in the elderly population with poor bone quality. Recently, there has been a significant increase in the use of reverse total shoulder arthroplasty (RTSA) as a treatment option in both acute fractures, as well as a salvage procedure for fracture sequelae (i.e., malunion, nonunion, fixation failure, tuberosity non-union). Despite the growing enthusiasm it remains unknown whether functional outcomes after RTSA as a salvage procedure are similar to those following acute RTSA. As a result, the purpose of this systematic review was to compare functional outcomes after RTSA as a primary versus salvage procedure for displaced PHF in the elderly.

A literature search of the electronic databases EMBASE, MEDLINE, and PubMed was conducted to identify all studies comparing RTSA as a primary treatment for displaced PHF and as a salvage procedure for failed initial management. Only studies with a minimum follow-up of two years were included. Data pertaining to range of motion, patient reported outcome measures and complications were extracted from eligible studies and entered into a meta-analysis software package (RevMan version 5.1, The Cochrane Collaboration) for pooled analysis. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of eligible studies.

The search identified four studies consisting of 200 patients with a mean age of 73.3 years and a mean follow-up of 3.2 years. There were a total of 76 patients (75% female) who underwent acute RTSA following displaced PHF, while 124 patients (77% female) required salvage RTSA for failure of initial treatment. Primary RTSA was found to have significantly higher American Shoulder and Elbow (ASES) (P = 0.04), Constant (P = 0.01) and University of California at Los Angeles (UCLA) (P = 0.0004) scores compared to salvage RTSA. Forward flexion (P = 0.001) and external rotation (P< 0.0001) were significantly greater amongst those undergoing RTSA acutely versus as a salvage procedure. The odds of having a complication (e.g., infection, dislocation, fracture) were 76% lower amongst those who had primary RTSA compared to salvage RTSA (P = 0.02). The overall quality of eligible studies was moderate to high.

Based on the current available evidence, elderly patients with displaced PHF have significantly greater range of motion, higher patient reported outcomes and lower risk of complications with primary RTSA compared to those undergoing RTSA as a salvage procedure. Additional prospective studies are warranted to confirm these findings.

F. Kassam G. Wood A. Marsh B. Elsolh C. Griffiths J. Hobson H. Grant M. M. Harrison

Necrotizing Fasciitis (NF) is a life-threatening infectious condition which requires expedient diagnosis to proceed with urgent surgical debridement. However, it can be difficult to establish an early diagnosis and expedite operative management as signs and symptoms are often non-specific and may mimic other pathology. Scoring systems such as The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) have been proposed to incorporate laboratory findings to predict whether a soft tissue infection is likely to be NF. Recent studies have found the sensitivity and specificity of the LRINEC tool to be lower than originally cited by the LRINEC authors in a validation cohort. Furthermore, there seems to be a predilection for certain geographic locations of patients with NF transferred to our tertiary care center for management, however, to our knowledge, geographic risk factors for NF have not been reported. This study also aims to determine the morbidity and mortality rate of NF at our Canadian tertiary hospital in recent years.

Comorbidities such as smoking, diabetes, and steroid use will be analyzed for any correlation with developing NF. Identification of patient factors in correlation with laboratory values may help identify patients at higher risk for having NF upon their presentation to the emergency department. A resultant earlier diagnosis of necrotizing soft tissue infections would allow for earlier surgical debridement and positively influence patient outcomes.

A retrospective chart review of 125 cases of NF at Kingston Health Sciences Centre from 2005 to 2017 was carried out to assess the validity of the LRINEC in our population and to examine the effect of comorbid factors such as smoking, diabetes, and corticosteroid use on the development of NF. The study cohort included patients treated by all surgical disciplines at our institution over twelve years. A separate cohort of 125 cellulitis or abscess cases was analyzed to assess the validity of the LRINEC tool in differentiating necrotizing fasciitis from non-necrotizing infections such as cellulitis and soft tissue abscess.

The 30-day mortality rate of NF treated at our institution during the study period was 21%. Advanced age was found to be a significant risk factor for death within 30 days of diagnosis (p=0.001). Smoking and steroid use were both found to increase risk for developing NF (p=0.01 and p=0.03, respectively). Diabetes did not appear to increase risk NF. There was no statistical difference in mortality rates between males and females with NF. The sensitivity of LRINEC in detecting NF was only 47% with a specificity of 74%.

The mortality rate of NF at our center is similar to that of other countries in recent years. Males and females have nearly equal mortality rates from NF. Smoking and steroid use appear to increase risk for developing NF, while diabetes may not. The LRINEC assessment tool alone may underestimate risk for developing NF, however, use of other clinical factors such as comorbidity analysis will further aide in the diagnosis of NF allowing for earlier surgical debridement.

E. Gusnowski P. Schneider K. Thomas

Distal radius fractures (DRF) are the most common fracture type in all age groups combined. Unstable DRF may be surgically managed with volar or dorsal plate fixation. Dorsal plating has traditionally been associated with decreased range of motion (ROM). However, this assumption has not been recently assessed to determine whether functional ROM is achievable (approximately 54o of flexion and 60o of extension) with recent advances in lower profile dorsal plate design. The aim of this study was therefore to compare ROM and patient reported outcome measures between volar and dorsal plating methods for DRF.

A meta-analysis was performed to directly compare ROM and DASH scores between dorsal and volar plate fixation for DRF. Separate literature searches for each plating method were performed using MedLine and EMBase on January 28, 2018. Exclusion criteria consisted of non-English articles, basic science articles, animal/cadaver studies, case studies/series, combined operative approaches, papers published more than 20 years ago and paediatric studies. Only articles with at least one year patient follow-up and a) ROM and AO distal radius fracture classification, or b) DASH scores were included. Raw data was extracted from all articles that met inclusion criteria to compile a comprehensive dataset for analysis. Descriptive statistics with z-score comparison for AO classification or a two-tailed independent samples t-test for ROM and DASH scores for dorsal versus volar plating were performed. Significance was defined as p < 0 .05.

After rigorous screening, 6 dorsal plating and 43 volar plating articles met inclusion criteria for ROM/AO classification versus 6 dorsal plating and 44 volar plating articles for DASH scores. The weighted means of flexion (dorsal 54.9o, SD 9.3, n=257, volar 61.3o, SD 11.5, n=1906) and extension (dorsal 60.0o, SD 12, n=257, volar 62.8o, SD 11.4, n=1906) were statistically significantly different (both p < 0 .001) between the two plating methods. The volar plating group had a significantly higher proportion of AO type C fractures (dorsal 0.5, n =169, volar 0.6, n=1246, p < 0 .001). The weighted means of reported DASH scores were not significantly different between dorsal (14.01, SD 14.8) versus volar (13.6, SD 12.8) plating (p=0.54).

Though mean wrist flexion and extension were statistically different between the dorsal versus volar plating methods, the difference between group means was less than 5o, which is unlikely to be clinically significant. Additionally, we did not find a significant difference in DASH scores between the two plating methods. Taken together, these findings imply that the statistical difference in ROM outcomes are likely not clinically significant and should therefore not dictate choice of plating method for fixation of DRF.