Introduction

Anterior cruciate ligament (ACL) injuries represent a significant burden of disease to the orthopaedic surgeon and often necessitate surgical reconstruction in the presence of instability. The hamstring graft has traditionally been used to reconstruct the ACL but the quadriceps tendon (QT) graft has gained popularity due to its relatively low donor site morbidity.

Abstract

Massive posterosuperior cuff tears (mRCT) retracted to the glenoid are surgically challenging and often associated with high retear rates. Primary repair is a less-favourable option and other salvage procedures such as SCR and tendon transfers are used. This study presents clinical and radiological outcomes of muscle advancement technique for repair of mRCT.

Sixty-one patients (mean age 57±6, 77% males and 23% females) (66 shoulders) underwent all-arthroscopic rotator cuff repair that included supraspinatus and infraspinatus subperiosteal dissection off scapular bony fossae, lateral advancement of tendon laminae, and tension-free double-layer Lasso Loop repair to footprint.

Pre-and post-operative range of motion (ROM), cuff strength, VAS, Constant, ASES, and UCLA scores were assessed. Radiologic assessment included modified Patte and Goutallier classifications. All patients had MRI at 6 months to evaluate healing and integrity of repair was assessed using Sugaya classification with Sugaya 4 and 5 considered retears.

Advanced fatty degeneration (Goutallier 3-4) was present in 44% and 20% of supraspinatus and infraspinatus. Tendon retraction was to the level of or medial to glenoid in 22%, and just lateral in 66%. 50.8% mRCT extended to teres minor. Subscapularis was partially torn (Lafosse 1-3) in 46% and completely torn (Lafosse 4-5) in 20%.

At mean follow-up (52.4 weeks), a significant increase in ROM, Relative Cuff Strength (from 57% to 90% compared to contralateral side), VAS (from 4 ±2.5 to 1±1.7), Constant (50±17.8 to 74 ±13.0), ASES (52 ±17.5 to 87 ±14.9), and UCLA (16± 4.9 to 30 ±4.9) scores were noted. There were six retears (10%), one failure due to P. acnes infection. 93% returned to pre-injury work and 89% of cases returned to pre-injury sport. Satisfaction rate was 96%.

Muscle advancement technique for mRCT is a viable option with low retear rates, restoration of ROM, strength, and excellent functional outcomes.

Introduction: The mechanobiology and response of bone formation to strain under physiological loading is well established, however investigation into exceedingly soft scaffolds relative to cancellous bone is limited. In this study we designed and 3D printed mechanically-optimised low-stiffness implants, targeting specific strain ranges inducing bone formation and assessed their biological performance in a pre-clinical in vivo load-bearing tibial tuberosity advancement (TTA) model. The TTA model provides an attractive pre-clinical framework to investigate implant osseointegration within an uneven loading environment due to the dominating patellar tendon force.

A knee finite element model from ovine CT data was developed to determine physiological target strains from simulated TTA surgery. We 3D printed low-stiffness Ti wedge osteotomy implants with homogeneous stiffness of 0.8 GPa (Ti1), 0.6 GPa (Ti2) and a locally-optimised design with a 0.3 GPa cortex and soft 0.1 GPa core (Ti3), for implantation in a 12-week ovine tibial advancement osteotomy (9mm). We quantitatively assessed bone fusion, bone area, mineral apposition rate and bone formation rate.

Optimised Ti3 implants exhibited evenly high strains throughout, despite uneven wedge osteotomy loading. We demonstrated that higher strains above 3.75%, led to greater bone formation. Histomorphometry showed uniform bone ingrowthin optimised Ti3 compared to homogeneous designs (Ti1 and Ti2), and greater bone-implant contact. The greatest bone formation scores were seen in Ti3, followed by Ti2 and Ti1.

Results from our study indicate lower stiffness and higher strain ranges than normally achieved in Ti scaffolds stimulate early bone formation. By accounting for loading environments through rational design, implants can be optimised to improve uniform osseointegration. Design and 3D printing of exceedingly soft titanium orthopaedic implants enhance strain induced bone formation and have significant importance in future implant design for knee, hip arthroplasty and treatment of large load-bearing bone defects.

Trauma and elective orthopaedic demands in New Zealand are increasing. In this study, prospective and retrospective data has been collected at Nelson Hospital and across New Zealand to identify the percentage of elective theatre time lost due to cancellation for acute patient care. Data has been collected from theatre management systems, hospital data systems and logged against secretarial case bookings, to calculate a percentage of elective theatre time lost to acute operating or insufficient bed capacity.

Data was collected over a five-month period at Nelson Hospital, with a total of 215 elective and 226 acute orthopaedic procedures completed. A total of 95 primary hip or knee arthroplasties were completed during this trial while 53 were cancelled. The total number of elective operative sessions (one session is the equivalent of a half day operating theatre time) lost to acute workload was 47.9. Thirty-three percent of allocated elective theatre time was cancelled - an equivalent of approximately one-full day elective operating per week.

Over a five-week period data was collected across all provincial hospitals in New Zealand, with an average of 18% of elective operating time per week lost due to acute workload. Elective cancellations were due to acute operating 40% of the time and bed shortages 60% of the time. The worst effected centre was Palmerston North which had an average of 33% of elective operating cancelled per week to accommodate acute surgery or due to bed shortages.

New Zealand's provincial orthopaedic surgeons are under immense pressure from acute operating that impedes provision of elective surgery. The New Zealand government definition of an ‘acute case’ does not reflect the nature of today's orthopaedic burden. Increasing and aging populations along with staff and infrastructure shortages have financial and societal impacts beyond medicine and require better definitions, further research, and funding from governance.

Clinical success of prostheses in joint arthroplasty is ultimately determined by survivorship and patient satisfaction. The purpose of this study was to compare (non-inferiority) a new morphometric designed stem for total hip arthroplasty (THA) against an established comparator.

A prospective randomised multi-centre study of 144 primary cementless THA performed by nine experienced orthopaedic surgeons was completed (70 received a fully coated collarless tapered stem and 74 received a morphometric designed proximally coated tapered stem). PROMs and blood serum markers were assessed preoperatively and at intervals up to 2-years postoperatively. In addition, measures of femoral stem fit, fill and subsidence at 2-years post-operatively were measured from radiographs by three observers, with an intra-class correlation coefficient of 0.918. A mixed effects model was employed to compare the two prosthesis over the study period. A p-value <0.05 was considered statistically significant.

Demographics, Dorr types and blood serum markers were similar between groups. Both stems demonstrated a significant improvement in PROMs between the pre- and post-operative measurements, with no difference at any timepoint (p > 0.05). The fully coated tapered collarless femoral stem had a non-significantly higher intra-operative femoral fracture rate (5.8% vs 1.4%, p = 0.24), with all patients treated with cable fixation and partial weight bearing. The mean subsidence at 2-years was 2.5mm +/− 2.3mm for the morphometric stem and 2.4mm +/− 1.8mm for the fully coated tapered collarless femoral stem (p = 0.879). There was one outlier in each group with increased subsidence (fully coated tapered collarless femoral stem 6.9mm, morphometric wedge stem 7.4mm), with both patients reporting thigh pain at 2 years.

When compared with an established stem, the newer designed morphometric wedge stem performed well with comparable radiological and PROM outcomes at 2 year follow up. Continued follow-up is required for long term benchmarking.

The minimisation of errors incurred during the learning process is thought to enhance motor learning and improve performance under pressure or in multitasking situations. If this is proven in surgical skills learning, it has the potential to enhance the delivery of surgical education. We aimed to compare errorless and errorful learning using the high-speed burr.

Medical students (n=30) were recruited and allocated randomly to an errorless or errorful group. The errorless learning group progressively learnt tasks from easy to difficult on cedar boards simulating bone. The errorful learning group also progressed through the same tasks but not in order of difficulty.

Transfer tasks assessed students’ performance of cervical laminoplasty on saw bone models to assess their level of learning from previous stages. During transfer task 2, students completed the procedure under time pressure and in the presence of distractors, in order to simulate real-life stressors in theatre. Accuracy, precision and safety of the procedure were scored by expert opinions from spine surgeons blinded to the grouping of the participants.

Both errorless and errorful learners demonstrated improvements in performance with increasing amounts of practice (demonstrated by the decreased time taken for the task as well as improvement in accuracy of the cuts (depth, width and smoothness). The performance of both groups was not impaired by the incorporation of a secondary task which required participants to multitask. No statistically significant difference in performance was noted between the two groups.

In contrast to previous research, there was no significant difference between errorless or errorful learning to develop skills with a high-speed, side-cutting burr. In both groups, practical learning during the session has led to improvement in overall performance with the burr relevant to cervical laminoplasty.

Malnutrition is considered a risk factor for postoperative complications in total hip and knee arthroplasty, though prospective studies investigating this assumption are lacking. The aim of this study was to prospectively analyse the 90-day postoperative complications, postoperative length of stay (LOS) and readmission rates of patients undergoing primary total hip and total kneearthroplasty using albumin, total lymphocyte count (TLC) and transferrin as serum markers of potential malnutrition.

603 primary hip and 823 primary knee arthroplasties over a 3-year period from a single centre wereprospectively analysed. BMI, demographic and comorbidity data were recorded. Complications werecategorised as surgical site infection, venous thromboembolism (deep vein thrombosis andpulmonary embolus), implant related (such as dislocation), and non-implant related (such aspneumonia). Outcomes were compared between groups, with malnutrition defined as serumalbumin <3.5g/dL, transferrin <200 mg/dL, or TLC <1,500 cells/mm³.

Potential malnutrition was present in 9.3% of the study population. This group experienced a longeraverage LOS at 6.5 days compared to the normal albumin group at 5.0 days (p=0.003). Surgical siteinfection rate was higher in the malnourished group (12.5 vs 7.8%, p=0.02). There was no differencebetween the two groups in implant related complications (0.8 vs 1.0%, p=0.95) medicalcomplications (7.8 vs 13.3%, p=0.17), rate of venous thromboembolism (2.3 vs 2.7%) or 90-dayreadmission rate (14.1 vs 17.0%, p=0.56). TLC and transferrin were not predictive of any of theprimary outcomes measured (p<0.05). Pacific Island (p<0.001), Indian (p=0.02) and Asian (p=0.02) patients had lower albumin than NZ European.

This study demonstrates an association between low albumin levels and increased postoperativeLOS and surgical site infection in total joint arthroplasty, providing rationale for consideration ofpreoperative nutritional screening and optimisation.

In 2021, Vigdorchik et al. published a large multicentre study validating their simple Hip-Spine Classification for determining patient-specific acetabular component positioning in total hip arthroplasty (THA). The purpose of our study was to apply this Hip-Spine Classification to a sample of Australian patients undergoing THA surgery to determine the local acetabular component positioning requirements. Additionally, we propose a modified algorithm for adjusting cup anteversion requirements.

790 patients who underwent THA surgery between January 2021 and June 2022 were assessed for anterior pelvic plane tilt (APPt) and sacral slope (SS) in standing and relaxed seated positions and categorized according to their spinal stiffness and flatback deformity. Spinal stiffness was measured using pelvic mobility (PM); the ΔSS between standing and relaxed seated. Flatback deformity was defined by APPt <−13° in standing. As in Vigdorchik et al., PM of <10° was considered a stiff spine. For our algorithm, PM of <20° indicated the need for increased cup anteversion. Using this approach, patient-specific cup anteversion is increased by 1° for every degree the patient's PM is <20°.

According to the Vigdorchik simple Hip-Spine classification groups, we found: 73% Group 1A, 19% Group 1B, 5% Group 2A, and 3% Group 2B. Therefore, under this classification, 27% of Australian THA patients would have an elevated risk of dislocation due to spinal deformity and/or stiffness. Under our modified definition, 52% patients would require increased cup anteversion to address spinal stiffness.

The Hip-Spine Classification is a simple algorithm that has been shown to indicate to surgeons when adjustments to acetabular cup anteversion are required to account for spinal stiffness or flatback deformity. We investigated this algorithm in an Australian population of patients undergoing THA and propose a modified approach: increasing cup anteversion by 1° for every degree the patient's PM is <20°.

Pelvic tilt (PT) is always described as the pelvic orientation along the transverse axis, yet four PT definitions were established based on different radiographic landmarks: anterior pelvic plane (PT_a), the centres of femoral heads and sacral plate (PT_m), pelvic outlet (PT_h), and sacral slope (SS). These landmarks quantify a similar concept, yet understanding of their relationships is lacking. Some studies referred to the words “pelvic tilt” for horizontal comparisons, but their PT definitions might differ. There is a demand for understanding their correlations and differences for education and research purposes.

This study recruited 105 sagittal pelvic radiographs (68 males and 37 females) from a single clinic awaiting their hip surgeries. Hip hardware and spine pathologies were examined for sub-group analysis. Two observers annotated four PTs in a gender-dependent manner and repeated it after six months. The linear regression model and intraclass correlation coefficient (ICC) were applied with a 95% significance interval.

The SS showed significant gender differences and the lowest correlations to the other parameters in the male group (−0.3< r <0.2). The correlations of SS in scoliosis (n = 7) and hip implant (female, n = 18) groups were statistically different, yet the sample sizes were too small. PT_m demonstrated very strong correlation to PT_h (r > 0.9) under the linear model PT_m = 0.951 × PT_h - 68.284.

The PT_m and PT_h are interchangeable under a simple linear regression model, which enables study comparisons between them. In the male group, SS is more of a personalised spinal landmark independent of the pelvic anatomy. Female patients with hip implant may have more static spinopelvic relationships following a certain pattern, yet a deeper study using a larger dataset is required. The understanding of different PTs improves anatomical education.

Source of the study: University of Auckland, Auckland, New Zealand and University of Otago, Christchurch, New Zealand

Outcomes following knee arthroplasty are typically defined as implant survivorship at defined timepoints, or revision incidence over time. These estimates are difficult to conceptualise, and lack context for younger patients with more remaining years of life. We therefore aimed to determine a ‘lifetime’ risk of revision as a more useful metric for total (TKA) and unicompartmental knee arthroplasty (UKA).

The New Zealand Joint Registry was used to identify 96,497 primary TKAs and 13,481 primary UKAs performed between 1999 and 2019. Patient mortality and revision incidence were also extracted. Estimates of lifetime risk were calculated using an actuarial lifetable method. The estimates were stratified by age and gender. Reasons for revision were categorised using previously published standardised definitions.

The lifetime risk of UKA revision was two-fold higher than TKA across all age groups (range 3.7-40.4% UKA, 1.6-22.4% TKA). Revision risk was higher for males with TKA (range 3.4%-25.2% males, 1.1%-20% females), but higher for females with UKA (range 4.3%-43.4% vs. 2.9%-37.4% for males). Revision due to infections were higher for TKA (1.5% males, 0.7% females) compared with UKA (0.4% males, 0.1% females). The increased risk in younger UKA patients was associated with higher incidence of aseptic loosening (UKA 2%, TKA 1%) and ‘unexplained pain’ (UKA 2%, TKA 0.2%).

The risk for UKA was two-fold higher than TKA, and this was partially explained by a higher proportion of revisions due to ‘unexplained pain’. For TKA, males had higher risk of revision, in contrast to UKA where females had higher risk; this gender difference was associated with higher incidence of infections with TKA. Younger age, gender and higher ASA status were also associated with increased lifetime risk of UKA revision. Lifetime risk of revision can provide a meaningful measure of arthroplasty outcomes to aid patient counselling.

Introduction

Virtual fracture clinics (VFC's) aim to reduce the number of outpatient appointments while improving the clinical effectiveness and patients experience through standardisation of treatment pathways. With 4.6% of ED admissions due to trauma the VFC prevents unnecessary face to face appointments providing a cost savings benefit to the NHS.

Currently, the consensus regarding subscapularis tendon repair during a reverse total shoulder arthroplasty (rTSA) is to do so if it is possible. Repair is thought to decrease the risk of dislocation and improve internal rotation but may also increase stiffness and improvement in internal rotation may be of subclinical benefit. Aim is to retrospectively evaluate the outcomes of rTSA, with or without a subscapularis tendon repair.

We completed a retrospective review of 51 participants (25 without and 26 with subscapularis repair) who received rTSR by a single-surgeon using a single-implant. Three patient reported outcome measures (PROM) were assessed pre-operatively and post-operative at twelve months, as well as range of movement (ROM) and plain radiographs. Statistical analysis utilized unpaired t tests for parametric variables and Mann-Whitney U test for nonparametric variables.

External Rotation ROM pre-operatively was the only variable with a significance difference (p=0.02) with the subscapularis tendon repaired group having a greater range. Pre- and post-operative abduction (p=0.72 & 0.58), forward flexion (p=0.67 & 0.34), ASES (p=0.0.06 & 0.78), Oxford (p=0.0.27 & 0.73) and post-operative external rotation (p=0.17)

Greater external rotation ROM pre-operatively may be indicative of the ability to repair the subscapularis tendon intra-operatively. However, repair does not seem to improve clinical outcome at 12 months.

There was no difference of the PROMs and AROMs between the subscapularis repaired and not repaired groups for any of the variables at the pre-operative or 12 month post operative with the exception of the external rotation ROM pre-operatively. We can conclude that from PROM or AROM perspective there is no difference if the tendon is repaired or not in a rTSR and indeed the patients without the repair may have improved outcomes at 12 months.

Introduction

Schatzker V & VI tibial plateau fractures are serious life-changing injuries often resulting in significant complications including post-traumatic arthritis. Reported incidence of secondary TKA following ORIF of all tibial plateau fractures is 7.3% and 13% for Schatzker V & VI tibial. This study reports a 15-year single centre experience of CEF of Schatzker V & VI fractures including PROMs and incidence of secondary TKA. This study was approved by the local Institutional board.

Introduction

Coronal malalignment and leg length discrepancies (LLD) are frequently associated. Temporary hemiepiphysiodesis (tHED) is commonly employed for the correction of limb malalignment in skeletally immature patients. For treatment of LLD greater than 2 cm, lengthening with intramedullary legnthening nails is a safe and reliable technique. However, the combined application of these approaches in skeletally immature patients has not yet been investigated.

Introduction

Circular external frames (CEF) are commonly used for a wide variety of indications, often when other devices are not appropriate. Circular frames are particularly associated with pin-site infection (PSI). Currently there is a gap in the available literature surrounding the risk of frame use with in-situ prosthetic joints. This retrospective study investigated the incidence of prosthetic joint infection (PJI) in a series of patients with in-situ arthroplasties treated with CEF.

Introduction

The management of fracture-related infection has undergone radical progress following the development of international guidelines. However, there is limited consideration to the realities of healthcare in low-resource environments due to a lack of available evidence in the literature from these settings. Initial antimicrobial suppression to support fracture union is frequently used in low- and middle-income countries despite the lack of published clinical evidence to support its practice. This study aimed to evaluate the outcomes following initial antimicrobial suppression to support fracture union in the management of fracture-related infection.

Introduction

Robotic-assisted total knee arthroplasty (TKA) has demonstrated significant benefits, including improved accuracy of component positioning compared to conventional jig-based TKA. However, previous studies have often failed to associate these findings with clinically significant improvements in patient-reported outcome measures (PROMs). Inertial measurement units (IMUs) provide a more nuanced assessment of a patient's functional recovery after TKA. This study aims to compare outcomes of patients undergoing robotic-assisted and conventional TKA in the early postoperative period using conventional PROMS and wearable sensors.

Introduction

This study assessed outcomes of total knee joint replacements (TKJR) in patients who had undergone previous periarticular osteotomy compared with unicompartmental knee replacement (UKR). Establishing a difference in the results of total knee joint replacements following these operations may be an important consideration in the decision-making and patient counselling around osteotomy versus UKR for the management of single-compartment osteoarthritis.

Concepts in glenoid tracking and treatment strategies of glenoid bone loss are well established. Initial observations in our practice in Singapore showed few patients with major bone loss requiring glenoid reconstructions. This led us to investigate the incidence of and the extent of bone loss in our patients with shoulder instability. Our study revealed bony Bankart lesions were seen in 46% of our patients but glenoid bone loss measured only 6–10% of the glenoid surface. In the same study we found that arthroscopic labral repair with capsular plication and Mason-Ellen suturing (Hybrid technique) was sufficient to stabilise patients with bipolar bone defects and minor glenoid bone loss. This led us to develop the concept of minor bone loss and a new algorithm.

Our algorithm and strategies to deal with major bone loss will also be discussed, and techniques & outcomes of Arthroscopic Bony Bankart repair, Arthroscopic Glenoid Reconstruction and Arthroscopic Remplissage procedures will be shown.

Aims

Global literature suggests that female surgical trainees have lower rates of independent operating (operative autonomy) than their male counterparts. The objective of this study was to identify any association between gender and lead/independent operating in speciality orthopaedic trainees within the UK national training programme.

Aims

Deprivation underpins many societal and health inequalities. COVID-19 has exacerbated these disparities, with access to planned care falling greatest in the most deprived areas of the UK during 2020. This study aimed to identify the impact of deprivation on patients on growing waiting lists for planned care.

Aims

The purpose of this survey study was to examine the demographic and lifestyle factors of women currently in orthopaedic surgery.

Aims

The use of fluoroscopy in orthopaedic surgery creates risk of radiation exposure to surgeons. Appropriate personal protective equipment (PPE) can help mitigate this. The primary aim of this study was to assess if current radiation protection in orthopaedic trauma is safe. The secondary aims were to describe normative data of radiation exposure during common orthopaedic procedures, evaluate ways to improve any deficits in protection, and validate the use of electronic personal dosimeters (EPDs) in assessing radiation dose in orthopaedic surgery.

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

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

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

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

Despite advances in treating acute spinal cord injury (SCI), measures to mitigate permanent neurological deficits in affected patients are limited. Augmentation of mean arterial blood pressure (MAP) to promote blood flow and oxygen delivery to the injured cord is one of the only currently available treatment options to potentially improve neurological outcomes after acute spinal cord injury (SCI). However, to optimize such hemodynamic management, clinicians require a method to measure and monitor the physiological effects of these MAP alterations within the injured cord in real-time. To address this unmet clinical need, we developed a series of miniaturized optical sensors and a monitoring system based on multi-wavelength near-infrared spectroscopy (MW-NIRS) technique for direct transdural measurement and continuous monitoring of spinal cord hemodynamics and oxygenation in real-time. We conducted a feasibility study in a porcine model of acute SCI. We also completed two separate animal studies to examine the function of the sensor and validity of collected data in an acute experiment and a seven-day post-injury survival experiment.

In our first animal experiment, nine Yorkshire pigs underwent a weight-drop T10 vertebral level contusion-compression injury and received episodes of ventilatory hypoxia and alterations in MAP. Spinal cord hemodynamics and oxygenation were monitored throughout by a transdural NIRS sensor prototype, as well as an invasive intraparenchymal (IP) sensor as a comparison. In a second experiment, we studied six Yucatan miniature pigs that underwent a T10 injury. Spinal cord oxygenation and hemodynamics parameters were continuously monitored by an improved NIRS sensor over a long period. Episodes of MAP alteration and hypoxia were performed acutely after injury and at two- and seven-days post-injury to simulate the types of hemodynamic changes patients experience after an acute SCI. All NIRS data were collected in real-time, recorded and analyzed in comparison with IP measures.

Noninvasive NIRS parameters of tissue oxygenation were highly correlated with invasive IP measures of tissue oxygenation in both studies. In particular, during periods of hypoxia and MAP alterations, changes of NIRS-derived spinal cord tissue oxygenation percentage were significant and corresponded well with the changes in spinal cord oxygen partial pressures measured by the IP sensors (p < 0.05).

Our studies indicate that a novel optical biosensor developed by our team can monitor real-time changes in spinal cord hemodynamics and oxygenation over the first seven days post-injury and can detect local tissue changes that are reflective of systemic hemodynamic changes. Our implantable spinal cord NIRS sensor is intended to help clinicians by providing real-time information about the effects of hemodynamic management on the injured spinal cord. Hence, our novel NIRS system has the near-term potential to impact clinical care and improve neurologic outcomes in acute SCI. To translate our studies from bench to bedside, we have developed an advanced clinical NIRS sensor that is ready to be implanted in the first cohort of acute SCI patients in 2022.

Aim

S. aureus and S. epidermidis remain the leading biofilm-forming agents causing orthopedic implant-associated infections (OIAI), but other coagulase-negative Staphylococcus (CoNS) with clinical importance is emerging. Besides, few studies have assessed specific genomic traits associated with patient outcome. This is a preliminary descriptive study of phenotypic and genomic features identified in clinical isolates of S. aureus and CoNS isolates recovered from OIAIs patients that progressed to treatment failure.

Shoulder arthroplasty humeral stem design has evolved to accommodate patient anatomy characteristics. As a result, stems are available in numerous shapes, coatings, lengths, sizes, and vary by fixation method. This abundance of stem options creates a surgical paradox of choice. Metrics describing stem stability, including a stem's resistance to subsidence and micromotion, are important factors that should influence stem selection, but have yet to be assessed in response to the diametral (i.e., thickness) sizing of short stem humeral implants.

Eight paired cadaveric humeri (age = 75±15 years) were reconstructed with surgeon selected ‘standard’ sized short-stemmed humeral implants, as well as 2mm ‘oversized’ implants. Stem sizing conditions were randomized to left and right humeral pairs. Following implantation, an anteroposterior radiograph was taken of each stem and the metaphyseal and diaphyseal fill ratios were quantified. Each humerus was then potted in polymethyl methacrylate bone cement and subjected to 2000 cycles of 90º forward flexion loading. At regular intervals during loading, stem subsidence and micromotion were assessed using a validated system of two optical markers attached to the stem and humeral pot (accuracy of <15µm).

The metaphyseal fill ratio did not differ significantly between the oversized and standard stems (0.50±0.06 vs 0.50±0.10; P = 0.997, Power = 0.05); however, the diaphyseal fill ratio did (0.52±0.06 vs 0.45±0.07; P < 0.001, Power = 1.0). Neither fill ratio correlated significantly with stem subsidence or micromotion. Stem subsidence and micromotion were found to plateau following 400 cycles of loading. Oversizing stem thickness prevented implant head-back contact in all but one specimen with the least dense metaphyseal bone, while standard sizing only yielded incomplete head-back contact in the two subjects with the densest bone. Oversized stems subsided significantly less than their standard counterparts (standard: 1.4±0.6mm, oversized: 0.5±0.5mm; P = 0.018, Power = 0.748;), and resulted in slightly more micromotion (standard: 169±59µm, oversized: 187±52µm, P = 0.506, Power = 0.094,).

Short stem diametral sizing (i.e., thickness) has an impact on stem subsidence and micromotion following humeral arthroplasty. In both cases, the resulting three-dimensional stem micromotion exceeded, the 150µm limit suggested for bone ingrowth, although that limit was derived from a uniaxial assessment. Though not statistically significant, the increased stem micromotion associated with stem oversizing may in-part be attributed to over-compacting the cancellous bed during broaching, which creates a denser, potentially smoother, interface, though this influence requires further assessment. The findings of the present investigation highlight the importance of proper short stem diametral sizing, as even a relatively small, 2mm, increase can negatively impact the subsidence and micromotion of the stem-bone construct. Future work should focus on developing tools and methods to support surgeons in what is currently a subjective process of stem selection.

Guidelines for the use of preoperative blood tests for elective surgery were established. However, there is less evidence and no guidelines regarding using these tests when a young, healthy patient undergoes minor orthopaedic trauma surgery. Bloodwork is often ordered routinely, regardless of medical history or the nature of the injury. We hypothesized that unnecessary blood work is requested for younger pre-operative patients, and their results will not change peri-operative management. This practice is not a judicious use of healthcare resources. This study aimed to evaluate the frequency, type, cost, and impact on clinical decisions if standard preoperative bloodwork was completed in healthy patients requiring surgical management of a minor fracture or dislocation.

After the approval of our institutional ethics board, a retrospective chart review was conducted. Inclusion criteria were patients aged 18-60 years, who had an isolated minor orthopaedic trauma requiring outpatient surgery, who were American Society of Anesthesiologists (ASA) class 1. ASA class 1 is defined as “a normal healthy patient, without any clinically important comorbidity and without a clinically significant past/present medical history.” Data records from January 1, 2016, to December 31, 2018, were extracted from a provincial database (the Analytics Data Integration, Measurement and Reporting) for five hospitals. Data including demographics, surgical treatment, type and number of blood tests ordered, and ordering physician were collected. Any abnormal test results were checked to see whether they led to a change in patient management or related to a postoperative adverse event. Independent samples t-tests and Chi-square tests were used to compare the characteristics of patients who had preoperative bloodwork versus those who did not. The cost of preoperative blood work was estimated.

During these two years, 627 patients met inclusion criteria, and 27% (n=168) of these patients had bloodwork completed pre-operatively, while only 34% (n=57) of these had one or more abnormal laboratory parameters. These abnormalities were minor and did not alter clinical management or result in repeated bloodwork peri-operatively. Patients who had bloodwork were significantly older (40.2 years) compared with patients without preoperative blood work (37.8 years; p=0.03), but there was no difference in sex between those who had bloodwork (53.4% male) and those who did not (51.4% male; p=0.63). The most common blood test ordered was a complete blood count, and the most commonly abnormal result was a mildly elevated white blood cell count (19%; n= 29). The most common patients to receive bloodwork were those with ankle (34%) and distal radius (34%) fractures. The bloodwork was primarily ordered by clinical associates (26%; n=46) and emergency department physicians (22%; n=38). Without considering lab personnel, consumables, and analysis time, the cost of this bloodwork was approximately $7685, an average of $45 per patient.

Pre-operative bloodwork in young, healthy, asymptomatic patients requiring outpatient surgery for minor orthopaedic trauma had no clinical significance and did not change patient management. Rigorous prospective research is warranted to establish national guidelines for appropriate pre-operative bloodwork ordering to minimize unnecessary and costly investigations.

Aim

Osteomyelitis is a difficult-to-treat disease with high chronification rates. The surgical amputation of the afflicted limb sometimes remains as the patients’ last resort. Several studies suggest an increase in mitochondrial fission as a possible contributor to the accumulation of intracellular reactive oxygen species and thereby to cell death of infectious bone cells. The aim of this study is to analyze the ultrastructural impact of bacterial infection and its accompanying microenvironmental tissue hypoxia on osteocytic and osteoblastic mitochondria.

Increased collection of patient-reported outcome measures (PROM) in registries enables international comparison of patient-centered outcomes after knee and hip replacement. We aimed to investigate 1) variations in PROM improvement, 2) the possible confounding factor of BMI, and 3) differences in comorbidity distributions between registries.

Registries affiliated with the International Society of Arthroplasty Registries (ISAR) or OECD membership countries were invited to report aggregate EQ-5D, OKS, OHS, HOOS-PS and KOOS-PS values. Eligible patients underwent primary total, unilateral knee or hip replacement for osteoarthritis within three years and had completed PROMs preoperatively and either 6 or 12 months postoperatively, excluding patients with subsequent revisions. For each PROM cohort, Chi-square tests were performed for BMI distributions across registries and 12 predefined PROM strata (male/female, age 20-64/65-74/>75, high or low preoperative PROM scores). Comorbidity distributions were reported for available comorbidity indexes.

Thirteen registries from 9 countries contributed data, n~130000 knee (range 140 to 79848) and n~113000 hip (range 137 to 85281). Mean EQ-5D index values (10 registries) ranged from 0.53 to 0.71 (knee) and 0.50 to 0.70 (hips) preoperatively and 0.78 to 0.85 (knee) and 0.83 to 0.87 (hip) postoperatively. Mean OKS (6 registries) ranged from 19.3 to 23.6 preoperatively and 36.2 to 41.2 postoperatively. Mean OHS (7 registries) ranged from 18.0 to 23.2 preoperatively and 39.8 to 44.2 postoperatively. Four registries reported KOOS-PS and three reported HOOS-PS. Proportions of patients with BMI >30 ranged from 35 to 62% (10 knee registries) and 16 to 43% (11 hip registries). For both knee and hip registries, distributions of patients across six BMI categories differed significantly among registries (p30 were for patients in the youngest age groups (20 to 64 and 65 to 74 years) with the lowest baseline scores. Additionally, females with lowest preoperative PROM scores had highest BMI. These findings were echoed for the OHS and OKS cohorts. Proportions of patients with ASA scores ≥3 ranged from 7 to 42% (9 knee registries) and 6 to 35% (8 hip registries).

PROM-score improvement varies between international registries, which may be partially explained by differences in age, sex and preoperative scores. BMI and comorbidity may be relevant to adjust for.

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

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

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

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

It has been established that a dedicated orthopaedic trauma room (DOTR) provides significant clinical and organizational benefits to the management of trauma patients. After-hours care is associated with surgeon fatigue, a high risk of patient complications, and increased costs related to staffing. However, hesitation due to concerns of the associated opportunity cost at the hospital leadership level is a major barrier to wide-spread adoption. The primary aim of this study is to determine the impact of dedicated orthopaedic trauma room (DOTR) implementation on operating room efficiency. Secondly, we sought to evaluate the associated financial impact of the DOTR, with respect to both after-hours care costs as well as the opportunity cost of displaced elective cases.

This was a retrospective cost-analysis study performed at a single academic-affiliated community hospital in Toronto, Canada. All patients that underwent the most frequently performed orthopedic trauma procedures (hip hemiarthroplasty, open reduction internal fixation of the ankle, femur, elbow and distal radius), over a four-year period from 2016-2019 were included. Patient data acquired for two-years prior and two-years after the implementation of a DOTR were compared, adjusting for the number of cases performed. Surgical duration and number of day-time and after-hours cases was recorded pre- and post-implementation. Cost savings of performing trauma cases during daytime and the opportunity cost of displacing elective cases by performing cases during the day was calculated. A sensitivity analysis accounting for varying overtime costs and hospital elective case profit was also performed.

1960 orthopaedic cases were examined pre- and post-DOTR. All procedures had reduced total operative time post-DOTR. After accounting for the total number of each procedure performed, the mean weighted reduction was 31.4% and the mean time saved was 29.6 minutes per surgery. The number of daytime surgical hours increased 21%, while nighttime hours decreased by 37.8%. Overtime staffing costs were reduced by $24,976 alongside increase in opportunity costs of $22,500. This resulted in a net profit of $2,476.

Our results support the premise that DOTRs improve operating room efficiency and can be cost efficient. Through the regular scheduling of a DOTR at a single hospital in Canada, the number of surgeries occurring during daytime hours increased while the number of after-hours cases decreased. The same surgeries were also completed nearly one-third faster (30 minutes per case) on average. Our study also specifically addresses the hesitation regarding potential loss of profit from elective surgeries. Notably, the savings partially stem from decreased OR time as well as decreased nurse overtime. Widespread implementation can improve patient care while still remaining financially favourable.

The number of women entering medical school has been steadily increasing over the past two decades; however, the number of women pursuing careers in orthopaedic surgery has not increased at the same rate. One of the suggested reasons for this discrepancy is the perceived incompatibility of having a family while upholding the demands of a surgical career in orthopaedics. A growing body of scientific literature has also outlined the increased rate of infertility and pregnancy complications in women surgeons. The extent to which these factors play a role in the recruitment and retention of women in orthopaedic surgery is unknown. Understanding pregnancy and parenthood in orthopaedic surgery is a critical first step in addressing this issue.

A scoping review was conducted to identify literature pertaining to the perceptions and experiences of pregnancy and/or parenthood of women in orthopaedic surgery. Embase, MEDLINE and PsychINFO were searched on June 7th, 2021 with Boolean operators to combine the following terms: orthop?e*, pregnancy, maternity, motherhood, parenthood, parental, and parenting. Studies pertaining to orthopaedic surgery residents, fellows and staff were included. The Arksey and O'Malley framework for scoping studies was followed. Descriptive statistics were used to quantify the included studies while thematic analysis as described by Braun and Clarke was used to analyze the qualitative data.

A total of 17 studies from 2006 to 2021 met inclusion criteria. Over half of the available research was conducted within the last two years (n=9, 53%). The majority of studies were conducted in the United States (n=15, 88%) and the United Kingdom (n=2, 12%). The most commonly used study design was survey-based research (n=13, 76%), followed by review studies (n=3, 18%), and case series (n=1, 6%). Thematic analysis revealed five key themes contributing to the women's experiences of pregnancy and/or parenthood in orthopaedics: (1) women are subtly or blatantly discouraged from becoming pregnant by their colleagues and superiors, (2) women delay childbearing to preserve their professional reputation, (3) there are higher rates of infertility and preterm labor in orthopaedic surgeons than in the general population, (4) the orthopaedic work environment can be hazardous and challenging for the pregnant woman, but accommodations are possible to mitigate risks, and (5) overall, there is limited support for pregnant and/or parenting women in orthopaedics throughout their career.

The first woman to be board-certified in orthopaedic surgery in the United States was Ruth Jackson in 1937. Eighty-four years later, orthopaedic surgery has the lowest number of women of the surgical specialties. The barriers related to pregnancy and/or parenthood during a woman's career in orthopaedics may be one cause. This study identified five themes related to pregnancy and parenthood that warrant further investigation. Qualitative research approaches can be used to elucidate the details of women's experiences and to provide suggestions for structural changes in the orthopaedic work environment.

Dual plate constructs have become an increasingly common fixation technique for midshaft clavicle fractures and typically involve the use of mini-fragment plates. The goal of this technique is to reduce plate prominence and implant irritation, as these are common reasons for revision surgery. However, limited biomechanical data exist for these lower-profile constructs. The study aim was to compare dual mini-fragment orthogonal plating to traditional small-fragment clavicle plates for biomechanical non-inferiority and to determine if an optimal plate configuration could be identified, using a cadaveric model.

Twenty-four cadaveric clavicles were randomized to one of six groups (n=4 per group), stratified by CT-based bone mineral content (BMC). The six different plating configurations compared were: pre-contoured superior or anterior fixation using a single 3.5-mm LC-DC plate, and four different dual-plating constructs utilizing 2.4-mm and 2.7-mm reconstruction or LC-DC plates. The clavicles were plated and then osteotomized to create an inferior butterfly fracture, which was then fixed with a single interfragmentary screw (OTA 15.2B). Axial, torsional, and bending (anterior and superior surface loading) stiffness were determined for each construct through non-destructive cyclic testing, using an MTS 858 Bionix materials testing system. This was followed by a load-to-failure test in three-point superior-surface bending. Kruskal-Wallace H and Mann-Whitney U were used to test for statistical significance.

There were no significant differences in BMC (median 7.9 g, range 4.2-13.8 g) for the six groups (p=1.000). For axial stiffness, the two dual-plate constructs with a superior 2.4-mm and anterior 2.7-mm plate (either reconstruction or LC-DC) were significantly stiffer than the other four constructs (p=0.021). For both superior and anterior bending, the superior 2.4-mm and anterior 2.7-mm plate constructs were significantly stiffer when compared to the 3.5-mm superior plate (p=0.043). In addition, a 3.5-mm plate placed anterior was a stiffer construct than a superior 3.5-mm plate (p=0.043). No significant differences were found in torsional stiffness or load-to-failure between the different constructs.

Dual plating using mini-fragment plates is biomechanically superior for fixation of midshaft clavicle fractures when compared to a single superior 3.5-mm plate and has similar biomechanical properties to a 3.5-mm plate placed anteriorly. With the exception of axial stiffness, no significant differences were found when different dual plating constructs were compared to each other. However, placing a 2.4-mm plate superiorly in combination with a 2.7-mm plate anteriorly might be the optimal construct, given the biomechanical superiority over the 3.5-mm plate placed superior.

Abstract

Source of Study: London, United Kingdom

This intervention study was conducted to assess two developing protocols for quadriceps and hamstring rehabilitation: Blood Flow Restriction (BFR) and Neuromuscular Electrical Stimulation Training (NMES). BFR involves the application of an external compression cuff to the proximal thigh. In NMES training a portable electrical stimulation unit is connected to the limb via 4 electrodes. In both training modalities, following device application, a standardised set of exercises were performed by all participants. BFR and NMES have been developed to assist with rehabilitation following lower limb trauma and surgery. They offer an alternative for individuals who are unable to tolerate the high mechanical stresses associated with traditional rehabilitation programmes.

The use of BFR and NMES in this study was compared across a total of 20 participants. Following allocation into one of the training programmes, the individuals completed training programmes across a 4-week period. Post-intervention outcomes were assessed using Surface Electromyography (EMG) which recorded EMG amplitude values for the following muscles: Vastus Medialis, Vastus Lateralis, Rectus Femoris and Semitendinosus.

Increased Semitendinosus muscle activation was observed post intervention in both BFR and NMES training groups. Statistically significant differences between the two groups was not identified. Larger scale randomised-controlled trials are recommended to further assess for possible treatment effects in these promising training modalities.

Aim

The analysis of synovial fluid has proved to be of crucial importance in the diagnostic process of prosthetic joint infections (PJI), suggesting the presence of an infection before the microbiological culture results. In this context, several studies illustrated the efficacy of synovial calprotectin in supporting the diagnosis of PJI [1, 2]. However, several testing methods have been explored to detect synovial calprotectin levels, emphasizing the need to use a standardized, rapid and rapid test.

In this study, synovial calprotectin was analyzed by means of a commercial stool test [3] to explore whether the detected levels might predict PJIs and, therefore, being a promising tool for the fast and reliable diagnosis of this complication.

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

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

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

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

Previously, we conducted a multi-center, double-blinded randomized controlled trial comparing arthroscopic Bankart repair with and without remplissage. The end point for the randomized controlled trial was two years post-operative, providing support for the benefits of remplissage in the short term in reducing recurrent instability. The aim of this study was to compare the medium term (3 to 9 years) outcomes of patients previously randomized to have undergone isolated Bankart repair (NO REMP) or Bankart repair with remplissage (REMP) for the management of recurrent anterior glenohumeral instability. The rate of recurrent instability and instances of re-operation were examined.

The original study was a double-blinded, randomized clinical trial with two 1:1 parallel groups with recruitment undertaken between 2011 and 2017. For this medium-term study, participants were reached for a telephone follow-up in 2020 and asked a series of standardized questions regarding ensuing instances of subluxation, dislocation or reoperation that had occurred on their shoulder for which they were randomized. Descriptive statistics were generated for all variables. “Failure” was defined as occurrence of a dislocation. “Recurrent instability” was defined as the participant reporting a dislocation or two or more occurences of subluxation greater than one year post-operative. All analyses were undertaken based on intention-to-treat whereby their data was analyzed based on the group to which they were originally allocated.

One-hundred and eight participants were randomized of which 50 in the NO REMP group and 52 in the REMP group were included in the analyses in the original study. The mean number of months from surgery to final follow-up was 49.3 for the NO REMP group and 53.8 for the REMP group. The rates of re-dislocation or failure were 8% (4/52) in the REMP group at an average of 23.8 months post-operative versus 22% (11/50) in the NO REMP at an average of 16.5 months post-operative. The rates of recurrent instability were 10% (5/52) in the REMP group at an average of 24 months post-operative versus 30% (15/50) in the NO REMP group at an average of 19.5 months post-operative. Survival curves were significantly different favouring REMP in both scenarios.

Arthroscopic Bankart repair combined with remplissage is an effective procedure in the treatment of patients with an engaging Hill-Sachs lesion and minimal glenoid bone loss (<15%). Patients can expect favourable rates of recurrent instability when compared with isolated Bankart repair at medium term follw-up.

Aim

To investigate the incidence and time-trend in reoperation due to deep Surgical Site Infection (SSI) following hip fracture surgery.

Abstract

To describe the longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing TKA and the associated impact on complications and lengths of hospital stay.

We identified patients who underwent primary TKA between 2006 – 2017 within the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We recorded patient demographics, length of stay (LOS), and 30-day major and minor complications. We labelled those with an obese Body Mass Index (BMI ≥ 30), hypertension, and diabetes as having MetS. We evaluated mean BMI, LOS, and 30-day complication rates in all patients, obese patients, and those with MetS from 2006-2017. We used multivariable regression to evaluate the trends in BMI, complications, and LOS over time in all patients and those with MetS, and the effect of BMI and MetS on complication rates and LOS, stratified by year.

270,846 patients underwent primary TKA at hospitals participating in the NSQIP database. 63.71% of patients were obese (n = 172,333), 15.21% were morbidly obese (n = 41,130), and 12.37% met criteria for MetS (n = 33,470). Mean BMI in TKA patients increased at a rate of 0.03 per year (0.02-0.05; p < 0 .0001). Despite this, the rate of adverse events in obese patients decreased: major complications by an odds ratio (OR) of 0.94 (0.93-0.96; p < 0 .0001) and minor complications by 0.94 (0.93-0.95; p < 0 .001). LOS also decreased over time at an average rate of −0.058 days per year (-0.059 to −0.057; p < 0 .0001). The proportion of patients with MetS did not increase, however similar improvements in major complications (OR 0.94 [0.91-0.97] p < 0 .0001), minor complications (OR 0.97 [0.94-1.00]; p < 0 .0330), and LOS (mean −0.055 [-0.056 to −0.054] p < 0 .0001) were found. In morbidly obese patients (BMI ≥ 40), there was a decreased proportion per year (OR 0.989 [0.98-0.994] p < 0 .0001). Factors specifically associated with major complications in obese patients included COPD (OR 1.75 [1.55-2.00] p < 0.0001) and diabetes (OR 1.10 [1.02-1.1] p = 0.017). Hypertension (OR 1.12 [1.03-1.21] p = 0.0079) was associated with minor complications. Similarly, in patients with MetS, major complications were associated with COPD (OR 1.72 [1.35-2.18] p < 0.0001). Neuraxial anesthesia was associated with a lower risk for major complications in the obese cohort (OR 0.87 [0.81-0.92] p < 0.0001). BMI ≥ 40 was associated with a greater risk for minor complications (OR 1.37 [1.26-1.50] p < 0.0001), major complications (1.11 [1.02-1.21] p = 0.015), and increased LOS (+0.08 days [0.07-0.09] p < 0.0001).

Mean BMI in patients undergoing primary TKA increased from 2006 - 2017. MetS comorbidities such as diabetes and hypertension elevated the risk for complications in obese patients. COPD contributed to higher rates of major complications. The obesity-specific risk reduction with spinal anesthesia suggests an improved post-anesthetic clinical course in obese patients with pre-existing pulmonary pathology. Encouragingly, the overall rates of complications and LOS in patients with obesity and MetS exhibited a longitudinal decline. This finding may be related to the decreased proportion of patients with BMI ≥ 40 treated over the same period, possibly the result of quality improvement initiatives aimed at delaying high-risk surgery in morbidly obese patients until healthy weight loss is achieved. These findings may also reflect increased awareness and improved management of these patients and their elevated risk profiles.

Abstract

The Accolade®TMZF is a taper-wedge cementless metaphyseal coated femoral stem widely utilized from 2002-2012. In recent years, there have been reports of early catastrophic failure of this implant. Establishing a deeper understanding of the rate and causes of revision in patients who developed aseptic failure in stems with documented concerns about high failure rates is critical. Understanding any potential patient or implant factors which are risk factors for failure is important to inform both clinicians and patients. We propose a study to establish the long-term survival of this stem and analyze patients who underwent aseptic revision to understand the causes and risk factors for failure.

A retrospective review was undertaken of all patients who received a primary total hip arthroplasty with an Accolade® TMZF stem at a high-volume arthroplasty center. The causes and timing of revision surgery were documented and cross referenced with the Canadian Institute of Health Information Discharge Abstract Database to minimize loss to follow-up. Survivorship analysis was performed with use of the Kaplan-Meier curves to determine the overall and aseptic survival rates at final follow-up. Patient and implant factors commonly associated with aseptic failure were extracted and Cox proportional hazards model was used.

A consecutive series of 2609 unilateral primary THA patients implanted with an Accolade®TMZF femoral hip stem were included. Mean time from primary surgery was 12.4 years (range 22 days to 19.5 years). Cumulative survival was 96.1% ± 0.2 at final follow-up. One hundred and seven patients underwent revision surgery with aseptic loosening of the femoral component was the most common cause of aseptic failure in this cohort (33/2609, 1.3%). Younger age and larger femoral head offset were independent risk factors for aseptic failure.

To our knowledge, this is the largest series representing the longest follow-up of this taper-wedge cementless femoral implant. Despite early concerns, the Accolade® TMZF stem has excellent survivorship in this cohort. Trunnionosis as a recognized cause for revision surgery was rare. Younger age and larger femoral head offset were independent risk factors for aseptic failure.

This study aimed to identify factors associated with increased rates of blood transfusion in patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion (PSF).

A retrospective case-control study was performed for AIS patients treated at a large children's hospital between August 2018 and December 2020. All patients with a diagnosis of AIS were evaluated. Data on patient demographics, AIS, and transfusion parameters were collected. Univariate regression and multivariate logistic modeling were utilized to assess risk factors associated with requiring transfusion. Odds ratios (OR) and 95% confidence interval (CI) were calculated. Surgeries were done by three surgeons and thirty anesthesiologists. To quantify the influence of anesthesia practice preferences a categorical variable was defined as “higher-transfusion practice preference”, for the provider with the highest rate of transfusion.

A total of 157 AIS patients were included, of whom 56 were transfused RBC units (cases), and 101 did not receive any RBC transfusion (controls). On univariate analysis, the following variables were significantly correlated with receiving RBC transfusion: “higher-transfusion practice preference,” “administration of crystalloids,” “receiving fresh frozen plasma (FFP),” “receiving platelets,” “pre-operative hemoglobin,” “cell saver volume,” and “surgical time.” On multiple regression modeling, “pre-operative hemoglobin less than 120 g/L” (OR 14.05, 95% CI: 1.951 to 135.7) and “higher-transfusion practice preference” (OR 11.84, 95% CI: 2.505 to 63.65) were found to be meaningfully and significantly predictive of RBC transfusion.

In this cohort, we identified pre-operative hemoglobin of 120 g/L as a critical threshold for requiring transfusion. In addition, we identified significant contribution from anesthesia transfusion practice preferences. Our multivariate model indicated that these two factors are the major significant contributors to allogenic blood transfusion. Although further studies are required to better understand factors contributing to transfusion in AIS patients, we suggest standardized, peri-operative evidence-based strategies to potentially help reduce variations due to individual provider preferences.

Aim

Prompt and sufficient broad spectrum empirical antibiotic treatment is key to prevent infection following open tibial fractures. Succeeding co-administration, we dynamically assessed the time for which vancomycin and meropenem concentrations were above relevant epidemiological cut-off minimal inhibitory concentrations (T>MIC) in tibial compartments for the bacteria most frequently encountered in open fractures. Low and high MIC-targets were applied: 1 and 4 µg/mL for vancomycin and 0.125 and 2 µg/mL for meropenem.

Single level discectomy (SLD) is one of the most commonly performed spinal surgery procedures. Two key drivers of their cost-of-care are duration of surgery (DOS) and postoperative length of stay (LOS). Therefore, the ability to preoperatively predict SLD DOS and LOS has substantial implications for both hospital and healthcare system finances, scheduling and resource allocation. As such, the goal of this study was to predict DOS and LOS for SLD using machine learning models (MLMs) constructed on preoperative factors using a large North American database.

The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for SLD procedures from 2014-2019. The dataset was split in a 60/20/20 ratio of training/validation/testing based on year. Various MLMs (traditional regression models, tree-based models, and multilayer perceptron neural networks) were used and evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure real world applicability, the results of the models were compared to a mean regressor model.

A total of 11,525 patients were included in this study. During validation, the neural network model (NNM) had the best MSEs for DOS (0.99) and LOS (0.67). During testing, the NNM had the best MSEs for DOS (0.89) and LOS (0.65). The NNM yielded the best 30-minute buffer accuracy for DOS (70.9%) and ≤120 min, >120 min classification accuracy (86.8%). The NNM had the best 1-day buffer accuracy for LOS (84.5%) and ≤2 days, >2 days classification accuracy (94.6%). All models were more accurate than the mean regressors for both DOS and LOS predictions.

We successfully demonstrated that MLMs can be used to accurately predict the DOS and LOS of SLD based on preoperative factors. This big-data application has significant practical implications with respect to surgical scheduling and inpatient bedflow, as well as major implications for both private and publicly funded healthcare systems. Incorporating this artificial intelligence technique in real-time hospital operations would be enhanced by including institution-specific operational factors such as surgical team and operating room workflow.

While controversy remains as to the relative benefit of operative (OM) versus non-operative management (NOM) of Achilles tendon ruptures (ATR), few studies have examined the effect on high impact maneuvers such as jumping and hopping. The purpose of this study is to compare functional performance and musculotendinous morphology in patients following OM or NOM for acute ATR.

Eligible patients were aged 18-65 years old with an ATR who underwent OM or NOM within three weeks of injury and were at least one-year post injury. Gastrocnemius muscle thickness and Achilles tendon length and thickness were assessed with ultrasound. Functional performance was examined with single-leg hop tests and isokinetic plantar strength at 60o/s and 120o/s.

24 participants completed testing (12/ group). Medial (OM: 2.2 ± 0.4 cm vs 1.9 ± 0.3 cm, NOM 2.15 ± 0.5 cm vs 1.7 ± 0.5 cm; p = 0.002) and lateral (OM 1.8 ± 0.3 cm vs 1.5 ± 0.4 cm, NOM 1.6 ± 0.4 cm vs 1.3 ± 0.5 cm; p = 0.008) gastrocnemius thickness were reduced on the affected limb. The Achilles tendon was longer (OM: 19.9 ± 2.2 cm vs 21.9 ± 1.6 cm; NOM: 19.0 ± 3.7 cm vs 21.4 ± 2.9 cm; p = 0.009) and thicker (OM: 0.48 ± 0.16 cm vs 1.24 ± 0.20 cm; NOM: 0.54 ± 0.08 cm vs 1.13 ± 0.23 cm; p < 0.001) on the affected limb with no differences between groups. Affected limb plantar flexion torque at 20o plantar flexion was reduced at 60o/s (OM: 55.6 ± 20.2 nm vs 47.8 ± 18.3 nm; NOM: 59.5 ± 27.5 nm vs 44.7 ± 21.0 nm; p = 0.06) and 120o/s (OM: 44.6 ± 17.9 nm vs 36.6 ± 15.0 nm; NOM: 48.6 ± 16.9 nm vs 35.8 ± 10.7 nm; p = 0.028) with no group effect. There was no difference in single leg hop performance. Achilles tendon length explained 31.6% (p = 0.003) and 18.0% (p = 0.025) of the variance in plantar flexion peak torque limb symmetry index (LSI) at 60o/s and 120o/s respectively. Tendon length explained 28.6% (p=0.006) and 9.5% (p = 0.087) of LSI when torque was measured at 20o plantar flexion at 60o/s and 120o/s respectively. Conversely, tendon length did not predict affected limb plantar flexion peak torque (nm), angle-specific torque at 20o plantar flexion (nm) and affected limb single leg hop distance (cm) or LSI (%).

There was no difference in tendon length between treatment groups and deficits in gastrocnemius thickness and strength are persistent. Deficits in the plantar flexion strength LSI are partially explained by increased tendon length following Achilles tendon rupture, regardless of treatment strategy. Hop test performance is maintained and may be the result of compensatory movements at other joints despite persistent plantarflexion weakness.

Knee arthroscopy with meniscectomy is the third most common Orthopaedic surgery performed after TKA and THA, comprising up to 16.6% of all procedures. The efficiency of Orthopaedic care delivery with respect to waiting times and systemic costs is extremely concerning. Canadian Orthopaedic patients experience the longest wait times of any G7 country, yet perioperative surgical care constitutes a significant portion of a hospital's budget.

In-Office Needle Arthroscopy (IONA) is an emerging technology that has been primarily studied as a diagnostic tool. Recent evidence shows that it is a cost-effective alternative to hospital- and community-based MRI with comparable accuracy. Recent procedure guides detailing IONA medial meniscectomy suggest a potential node for OR diversion. Given the high case volume of knee arthroscopy as well as the potential amenability to be diverted away from the OR to the office setting, IONA has the potential to generate considerable improvements in healthcare system efficiency with respect to throughput and cost savings. As such, the purpose of this study is to investigate the cost savings and impact on waiting times on a mid-sized Canadian community hospital if IONA is offered as an alternative to traditional operating room (OR) arthroscopy for medial meniscal tears.

In order to develop a comprehensive understanding and accurate representation of the quantifiable operations involved in the current state for medial meniscus tear care, process mapping was performed that describes the journey of a patient from when they present with knee pain to their general practitioner until case resolution. This technique was then repeated to create a second process map describing the hypothetical proposed state whereby OR diversion may be conducted utilizing IONA. Once the respective process maps for each state were determined, each process map was translated into a Dupont decision tree. In order to accurately determine the total number of patients which would be eligible for this care pathway at our institution, the OR booking scheduling for arthroscopy and meniscectomy/repair over a four year time period (2016-2020) were reviewed. A sensitivity analysis was performed to examine the effect of the number of patients who select IONA over meniscectomy and the number of revision meniscectomies after IONA on 1) the profit and profit margin determined by the MCS-Dupont financial model and 2) the throughput (percentage and number) determined by the MCS-throughput model.

Based on historic data at our institution, an average of 198 patients (SD 31) underwent either a meniscectomy or repair from years 2016-2020. Revenue for both states was similar (p = .22), with the current state revenue being $ 248,555.99 (standard deviation $ 39,005.43) and proposed state of $ 249,223.86 (SD $ 39,188.73). However, the reduction in expenses was significant (p < .0001) at 5.15%, with expenses in the current state being $ 281,415.23 (SD $ 44,157.80) and proposed state of $ 266,912.68 (SD $ 42,093.19), representing $14,502.95 in savings. Accordingly, profit improvement was also significant (p < .0001) at 46.2%, with current state profit being $ (32,859.24) (SD $ 5,153.49) and proposed state being $ (17,678.82) (SD $ 2,921.28). The addition of IONA into the care pathway of the proposed state produced an average improvement in throughput of 42 patients (SD 7), representing a 21.2% reduction in the number of patients that require an OR procedure. Financial sensitivity analysis revealed that the proposed state profit was higher than the current state profit if as few as 10% of patients select IONA, with the maximum revision rate needing to remain below 40% to achieve improved profits.

The most important finding from this study is that IONA is a cost-effective alternative to traditional surgical arthroscopy for medial meniscus meniscectomy. Importantly, IONA can also be used as a diagnostic procedure. It is shown to be a cost-effective alternative to MRI with similar diagnostic accuracy. The role of IONA as a joint diagnostic-therapeutic tool could positively impact MRI waiting times and MRI/MRA costs, and further reduce indirect costs to society. Given the well-established benefit of early meniscus treatment, accelerating both diagnosis and therapy is bound to result in positive effects.

Staphylococcus aureus is the most frequently isolated organism in periprosthetic joint infections. The mechanism by which synovial fluid (SF) kills bacteria has not yet been elucidated, and a better understanding of its antibacterial characteristics is needed. We sought to analyze the antimicrobial properties of exogenous copper in human SF against S. aureus.

SF samples were collected from patients undergoing total elective knee or hip arthroplasty. Different S. aureus strains previously found to be sensitive and resistant, UAMS-1 and USA300 WT, respectively, were used. We performed in-vitro growth and viability assays to determine the capability of S. aureus to survive in SF with the addition of 10µM of copper. We determined the minimum bactericidal concentration of copper (MBC-Cu) and evaluated the sensitivity to killing, comparing WT and CopAZB-deficient USA300 strains.

UAMS-1 evidenced a greater sensitivity to SF when compared to USA300 WT, at 12 (p=0.001) and 24 hours (p=0.027). UAMS-1 significantly died at 24 hours (p=0.017), and USA300 WT survived at 24 hours. UAMS-1 was more susceptible to the addition of copper at 4 (p=0.001), 12 (p=0.005) and 24-hours (p=0.006). We confirmed a high sensitivity to killing with the addition of exogenous copper on both strains at 4 (p=0.011), 12 (p=0.011), and 24 hours (p=0.011). Both WT and CopAZB-deficient USA300 strains significantly died in SF, evidencing a MBC-Cu of 50µM against USA300 WT (p=0.011).

SF has antimicrobial properties against S. aureus, and UAMS-1 was more sensitive than USA300 WT. The addition of 10µM of copper was highly toxic for both strains, confirming its bactericidal effect. We evidenced CopAZB-proteins involvement in copper effluxion by demonstrating the high sensitivity of the mutant strain to lower copper concentrations. Thus, we propose CopAZB-proteins as potential targets and the use of exogenous copper as possible treatment alternatives against S. aureus.