Risk of early revision in total hip arthroplasty: the relative contribution of the surgeon versus the hospital.

BACKGROUND: Early revision for total hip arthroplasty is a serious adverse outcome. There are multiple contributing risk factors for early revision. Risk factors can exist at the level of the surgeon and the level of the institution. The primary research question of this study was to determine the relative contribution of surgeon-level and hospital-level variance to rates of early revision (overall and for infection) after primary total hip arthroplasty. METHODS: This is a registry-based study from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Data for the most commonly used stem (Exeter V40) were used to reduce prosthesis variation from the analysis. A mixed effects Cox Model (also known as a frailty model) with crossed random effects for surgeon and hospital was used. Outcomes were early revision (within 2 years) for all causes and for infection. This model allowed for the risk of early revision to be explained by the variability at the surgeon level or hospital level. RESULTS: There were 32 031 procedures performed by 735 surgeons across 250 hospitals between 1 January 2015 and 31 December 2019. Surgeon variability significantly contributed to overall variation in revision for any cause and revision for infection (P < 0.0001). There was no significant contribution of hospital-level variation to overall revision or for infection. CONCLUSIONS: Surgeon-level factors play a more important role than institution-level factors in early revision after primary total hip arthroplasty. If surgeons are identified as having a higher risk of revision, there is potential for surgeon-level practice change to reduce the risk of early revision.

Trends in Pediatric Anterior Cruciate Ligament Reconstruction in Australia: An Analysis of Australian Medicare Benefits Schedule Database From 2001 to 2020.

BACKGROUND: Anterior cruciate ligament (ACL) injuries are common and increasingly prevalent in the pediatric population. However, there remain sparse epidemiological data on the surgical treatment of these injuries. The objective of this study is to assess the trends in the rate of pediatric ACL reconstruction in Australia over the past 2 decades. METHODS: The incidence of ACL reconstruction from 2001 to 2020 in patients 5 to 14 years of age was analyzed using the Australian Medicare Benefits Schedule (MBS) database. Data were stratified by sex and year. An offset term was introduced using population data from the Australian Bureau of Statistics to account for population changes over the study period. RESULTS: A total of 3719 reconstructions for the management of pediatric ACL injuries were performed in Australia under the MBS in the 20-year period from 2001 to 2020. There was a statistically significant annual increase in the total volume and per capita volume of pediatric ACL reconstructions performed across the study period ( P <0.0001). There was a significant increase in the rate of both male and female reconstructions ( P <0.0001), with a greater proportion of reconstructions performed on males (n=2073, 56%) than females (n=1646, 44%). In 2020, the rate of pediatric ACL reconstructions decreased to a level last seen in 2015, likely due to the effects of COVID-19. CONCLUSIONS: The incidence of ACL reconstruction in skeletally immature patients has increased in Australia over the 20-year study period. This increase is in keeping with evidence suggesting poor outcomes with nonoperative or delayed operative management.

Trial of Vancomycin and Cefazolin as Surgical Prophylaxis in Arthroplasty.

BACKGROUND: The addition of vancomycin to beta-lactam prophylaxis in arthroplasty may reduce surgical-site infections; however, the efficacy and safety are unclear. METHODS: In this multicenter, double-blind, superiority, placebo-controlled trial, we randomly assigned adult patients without known methicillin-resistant Staphylococcus aureus (MRSA) colonization who were undergoing arthroplasty to receive 1.5 g of vancomycin or normal saline placebo, in addition to cefazolin prophylaxis. The primary outcome was surgical-site infection within 90 days after surgery. RESULTS: A total of 4239 patients underwent randomization. Among 4113 patients in the modified intention-to-treat population (2233 undergoing knee arthroplasty, 1850 undergoing hip arthroplasty, and 30 undergoing shoulder arthroplasty), surgical-site infections occurred in 91 of 2044 patients (4.5%) in the vancomycin group and in 72 of 2069 patients (3.5%) in the placebo group (relative risk, 1.28; 95% confidence interval [CI], 0.94 to 1.73; P = 0.11). Among patients undergoing knee arthroplasty, surgical-site infections occurred in 63 of 1109 patients (5.7%) in the vancomyin group and in 42 of 1124 patients (3.7%) in the placebo group (relative risk, 1.52; 95% CI, 1.04 to 2.23). Among patients undergoing hip arthroplasty, surgical-site infections occurred in 28 of 920 patients (3.0%) in the vancomyin group and in 29 of 930 patients (3.1%) in the placebo group (relative risk, 0.98; 95% CI, 0.59 to 1.63). Adverse events occurred in 35 of 2010 patients (1.7%) in the vancomycin group and in 35 of 2030 patients (1.7%) in the placebo group, including hypersensitivity reactions in 24 of 2010 patients (1.2%) and 11 of 2030 patients (0.5%), respectively (relative risk, 2.20; 95% CI, 1.08 to 4.49), and acute kidney injury in 42 of 2010 patients (2.1%) and 74 of 2030 patients (3.6%), respectively (relative risk, 0.57; 95% CI, 0.39 to 0.83). CONCLUSIONS: The addition of vancomycin to cefazolin prophylaxis was not superior to placebo for the prevention of surgical-site infections in arthroplasty among patients without known MRSA colonization. (Funded by the Australian National Health and Medical Research Council; Australian New Zealand Clinical Trials Registry number, ACTRN12618000642280.).

Which hip morphology measures and patient factors are associated with age of onset and symptom severity in femoroacetabular impingement syndrome?

BACKGROUND: Bony morphology is central to the pathomechanism of femoroacetabular impingement syndrome (FAIS), however isolated radiographic measures poorly predict symptom onset and severity. More comprehensive morphology measurement considered together with patient factors may better predict symptom presentation. This study aimed to determine the morphological parameter(s) and patient factor(s) associated with symptom age of onset and severity in FAIS. METHODS: 99 participants (age 32.9 ± 10.5 years; body mass index (BMI 24.3 ± 3.1 kg/m2; 42% females) diagnosed with FAIS received standardised plain radiographs and magnetic resonance scans. Alpha angle in four radial planes (superior to anterior), acetabular version (AV), femoral torsion, lateral centre-edge, anterior centre-edge (ACEA) and femoral neck-shaft angles were measured. Age of symptom onset (age at presentation minus duration of symptoms), international Hip Outcome Tool-33 (iHOT-33) and modified UCLA activity scores were recorded. Backward stepwise regression assessed morphological parameters and patient factors (age, sex, BMI, symptom duration, annual income, private/public healthcare system accessed) to determine variables independently associated with onset age and iHOT-33 score. RESULTS: Earlier symptom onset was associated with larger superoanterior alpha angle (p = 0.007), smaller AV (p = 0.023), lower BMI (p = 0.010) and public healthcare system access (p = 0.041) (r2 = 0.320). Worse iHOT-33 score was associated with smaller ACEA (p = 0.034), female sex (p = 0.040), worse modified UCLA activity score (p = 0.010) and public healthcare system access (p < 0.001) (r2 = 0.340). CONCLUSIONS: Age of symptom onset was chiefly predicted by femoral and acetabular bony morphology measures, whereas symptom severity predominantly by patient factors. Factors measured explained a small amount of variance in the data; additional unmeasured factors may be more influential.

Moderators, Mediators, and Prognostic Indicators of Treatment With Hip Arthroscopy or Physical Therapy for Femoroacetabular Impingement Syndrome: Secondary Analyses From the Australian FASHIoN Trial.

BACKGROUND: Although randomized controlled trials comparing hip arthroscopy with physical therapy for the treatment of femoroacetabular impingement (FAI) syndrome have emerged, no studies have investigated potential moderators or mediators of change in hip-related quality of life. PURPOSE: To explore potential moderators, mediators, and prognostic indicators of the effect of hip arthroscopy and physical therapy on change in 33-item international Hip Outcome Tool (iHOT-33) score for FAI syndrome. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Overall, 99 participants were recruited from the clinics of orthopaedic surgeons and randomly allocated to treatment with hip arthroscopy or physical therapy. Change in iHOT-33 score from baseline to 12 months was the dependent outcome for analyses of moderators, mediators, and prognostic indicators. Variables investigated as potential moderators/prognostic indicators were demographic variables, symptom duration, alpha angle, lateral center-edge angle (LCEA), Hip Osteoarthritis MRI Scoring System (HOAMS) for selected magnetic resonance imaging (MRI) features, and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) score. Potential mediators investigated were change in chosen bony morphology measures, HOAMS, and dGEMRIC score from baseline to 12 months. For hip arthroscopy, intraoperative procedures performed (femoral ostectomy ± acetabular ostectomy ± labral repair ± ligamentum teres debridement) and quality of surgery graded by a blinded surgical review panel were investigated for potential association with iHOT-33 change. For physical therapy, fidelity to the physical therapy program was investigated for potential association with iHOT-33 change. RESULTS: A total of 81 participants were included in the final moderator/prognostic indicator analysis and 85 participants in the final mediator analysis after exclusion of those with missing data. No significant moderators or mediators of change in iHOT-33 score from baseline to 12 months were identified. Patients with smaller baseline LCEA (ß = -0.82; P = .034), access to private health care (ß = 12.91; P = .013), and worse baseline iHOT-33 score (ß = -0.48; P < .001) had greater iHOT-33 improvement from baseline to 12 months, irrespective of treatment allocation, and thus were prognostic indicators of treatment response. Unsatisfactory treatment fidelity was associated with worse treatment response (ß = -24.27; P = .013) for physical therapy. The quality of surgery and procedures performed were not associated with iHOT-33 change for hip arthroscopy (P = .460-.665 and P = .096-.824, respectively). CONCLUSION: No moderators or mediators of change in hip-related quality of life were identified for treatment of FAI syndrome with hip arthroscopy or physical therapy in these exploratory analyses. Patients who accessed the Australian private health care system, had smaller LCEAs, and had worse baseline iHOT-33 scores, experienced greater iHOT-33 improvement, irrespective of treatment allocation.

Comparison of Walking Biomechanics After Physical Therapist-Led Care or Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Secondary Analysis From a Randomized Controlled Trial.

BACKGROUND: Femoroacetabular impingement syndrome is characterized by chondrolabral damage and hip pain. The specific biomechanics used by people with femoroacetabular impingement syndrome during daily activities may exacerbate their symptoms. Femoroacetabular impingement syndrome can be treated nonoperatively or surgically; however, differential treatment effects on walking biomechanics have not been examined. PURPOSE: To compare the 12-month effects of physical therapist-led care or arthroscopy on trunk, pelvis, and hip kinematics as well as hip moments during walking. STUDY DESIGN: Secondary analysis of multi-centre, pragmatic, two-arm superiority randomized controlled trial subsample; Level of evidence, 1. METHODS: A subsample of 43 participants from the Australian Full randomised controlled trial of Arthroscopic Surgery for Hip Impingement versus best cONventional (FASHIoN trial) underwent gait analysis and completed the International Hip Outcome Tool (iHOT-33) at both baseline and 12 months after random allocation to physical therapist-led care (personalized hip therapy; n = 22; mean age 35; 41% female) or arthroscopy (n = 21; mean age 36; 48% female). Changes in trunk, pelvis, and hip biomechanics were compared between treatment groups across the gait cycle using statistical parametric mapping. Associations between changes in iHOT-33 and changes in hip kinematics across 3 planes of motion were examined. RESULTS: As compared with the arthroscopy group, the personalized hip therapy group increased its peak hip adduction moments (mean difference = 0.35 N·m/body weight·height [%] [95% CI, 0.05-0.65]; effect size = 0.72; P = .02). Hip adduction moments in the arthroscopy group were unchanged in response to treatment. No other between-group differences were detected. Improvements in iHOT-33 were not associated with changes in hip kinematics. CONCLUSION: Peak hip adduction moments were increased in the personalized hip therapy group and unchanged in the arthroscopy group. No biomechanical changes favoring arthroscopy were detected, suggesting that personalized hip therapy elicits greater changes in hip moments during walking at 12-month follow-up. Twelve-month changes in hip-related quality of life were not associated with changes in hip kinematics.

A rare case of an open transverse patella fracture in a 5-year-old child.

Patella fractures in children are rare accounting for 1 % of all paediatric fractures. Rarer still are transverse patella fractures in children with only 1 case previously described in the literature of a child less than the age of 6. We present the second case in the literature of a transverse patella fracture in a child, and the only case of a transverse fracture in a partially ossified patella in a 5-year-old. Our patient suffered an open patella fracture following fall with a flexed knee onto a broken tile. The case was successfully managed with adult fixation principles of patella fractures with a tension band wire construct. The patient had regular follow-up with knee radiographs showing a well healed fracture and a good range of motion of the knee at 3 months. The hardware was subsequently removed with no complications. In conclusion, we present an extremely rare case of an open transverse patella fracture in a child, utilising adult fixation principles of a patella which resulted in a successful outcome for the patient.

Hip Contact Force Magnitude and Regional Loading Patterns Are Altered in Those with Femoroacetabular Impingement Syndrome.

PURPOSE: The magnitude and location of hip contact force influence the local mechanical environment of the articular tissue, driving remodeling. We used a neuromusculoskeletal model to investigate hip contact force magnitudes and their regional loading patterns on the articular surfaces in those with femoroacetabular impingement (FAI) syndrome and controls during walking. METHODS: An EMG-assisted neuromusculoskeletal model was used to estimate hip contact forces in eligible participants with FAI syndrome ( n = 41) and controls ( n = 24), walking at self-selected speed. Hip contact forces were used to determine the average and spread of regional loading for femoral and acetabular articular surfaces. Hip contact force magnitude and region of loading were compared between groups using statistical parametric mapping and independent t -tests, respectively ( P < 0.05). RESULTS: All of the following findings are reported compared with controls. Those with FAI syndrome walked with lower-magnitude hip contact forces (mean difference, -0.7 N·BW -1 ; P < 0.001) during first and second halves of stance, and with lower anteroposterior, vertical, and mediolateral contact force vector components. Participants with FAI syndrome also had less between-participant variation in average regional loading, which was located more anteriorly (3.8°, P = 0.035) and laterally (2.2°, P = 0.01) on the acetabulum but more posteriorly (-4.8°, P = 0.01) on the femoral head. Participants with FAI syndrome had a smaller spread of regional loading across both the acetabulum (-1.9 mm, P = 0.049) and femoral head (1 mm, P < 0.001) during stance. CONCLUSIONS: Compared with controls, participants with FAI syndrome walked with lower-magnitude hip contact forces that were constrained to smaller regions on the acetabulum and femoral head. Differences in regional loading patterns might contribute to the mechanobiological processes driving cartilage maladaptation in those with FAI syndrome.

Can a Hip Brace Improve Short-Term Hip-Related Quality of Life for People With Femoroacetabular Impingement and Acetabular Labral Tears: An Exploratory Randomized Trial.

OBJECTIVES: To examine whether a hip brace can improve hip health quality-of-life (QoL) and is well-tolerated in people with femoroacetabular impingement syndrome (FAIS) or symptomatic labral tears after 6 weeks of wear. DESIGN: Parallel, two-arm, exploratory randomized trial. SETTING: Hospital and private clinics of orthopaedic surgeons. PARTICIPANTS: Individuals >18 years with FAIS or labral tears. INTERVENTIONS: Usual conservative care versus usual conservative care plus a hip brace. MAIN OUTCOMES: Patient-reported outcomes were assessed with the International Hip Outcome Tool (iHOT-33), and Copenhagen Hip and Groin Outcome Scores (HAGOS). Brace acceptability was measured using the Quebec User Evaluation of Satisfaction with Assistive Technology survey. Independent t-tests assessed between-group differences. RESULTS: Thirty-eight participants were recruited, 19 each group, 60% women, mean age 39.3 ± 11.8 years, body mass index 25.3 ± 4.4 kg/m2, iHOT-33 36.6 ± 24.8. Three participants dropped out (one usual care, 2 braced). The mean between-group difference for iHOT-33 was 19.4 (95% confidence interval [CI] 1.68-37.06, P = 0.03) favoring the brace. There were improvements in most HAGOS subscale scores favoring the brace. Issues with brace tolerability for some participants were perceived comfort and effectiveness. Three brace-related adverse events were reported. CONCLUSION: Between-group differences favored the braced group for hip health QoL, pain, symptoms, and function. Although these were promising results, the CIs for the estimates were wide, the small sample size likely a contributing factor. Our results suggest that further investigation of the brace is warranted, we calculated sample sizes and made recommendations for the design of a future trial.

Multi-centre randomised controlled trial comparing arthroscopic hip surgery to physiotherapist-led care for femoroacetabular impingement (FAI) syndrome on hip cartilage metabolism: the Australian FASHIoN trial.

BACKGROUND: Arthroscopic surgery for femoroacetabular impingement syndrome (FAI) is known to lead to self-reported symptom improvement. In the context of surgical interventions with known contextual effects and no true sham comparator trials, it is important to ascertain outcomes that are less susceptible to placebo effects. The primary aim of this trial was to determine if study participants with FAI who have hip arthroscopy demonstrate greater improvements in delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) index between baseline and 12 months, compared to participants who undergo physiotherapist-led management. METHODS: Multi-centre, pragmatic, two-arm superiority randomised controlled trial comparing physiotherapist-led management to hip arthroscopy for FAI. FAI participants were recruited from participating orthopaedic surgeons clinics, and randomly allocated to receive either physiotherapist-led conservative care or surgery. The surgical intervention was arthroscopic FAI surgery. The physiotherapist-led conservative management was an individualised physiotherapy program, named Personalised Hip Therapy (PHT). The primary outcome measure was change in dGEMRIC score between baseline and 12 months. Secondary outcomes included a range of patient-reported outcomes and structural measures relevant to FAI pathoanatomy and hip osteoarthritis development. Interventions were compared by intention-to-treat analysis. RESULTS: Ninety-nine participants were recruited, of mean age 33 years and 58% male. Primary outcome data were available for 53 participants (27 in surgical group, 26 in PHT). The adjusted group difference in change at 12 months in dGEMRIC was -59 ms (95%CI - 137.9 to - 19.6) (p = 0.14) favouring PHT. Hip-related quality of life (iHOT-33) showed improvements in both groups with the adjusted between-group difference at 12 months showing a statistically and clinically important improvement in arthroscopy of 14 units (95% CI 5.6 to 23.9) (p = 0.003). CONCLUSION: The primary outcome of dGEMRIC showed no statistically significant difference between PHT and arthroscopic hip surgery at 12 months of follow-up. Patients treated with surgery reported greater benefits in symptoms at 12 months compared to PHT, but these benefits are not explained by better hip cartilage metabolism. TRIAL REGISTRATION DETAILS: Australia New Zealand Clinical Trials Registry reference: ACTRN12615001177549 . Trial registered 2/11/2015.

Predicting dissatisfaction following total hip arthroplasty using a Bayesian model averaging approach: Results from the Australian Arthroplasty Clinical Outcomes Registry National (ACORN).

BACKGROUND: Total hip arthroplasty (THA) provides excellent pain relief and improved function in patients with painful arthritis. The aim of this study was to identify rates and predictors of dissatisfaction following THA. METHODS: Data were collected prospectively from the Australian Arthroplasty Clinical Outcomes Registry National (ACORN) database between 2014 and 2016 from 2096 patients who underwent THA. Data included baseline demographics, patient-reported outcome measures (PROMs) and postoperative clinical outcomes. Patients were dichotomized into two groups based on their 6-month response to the satisfaction question answered on a Likert scale. Eighteen predefined variables were analyzed. PROMs included full Oxford Hip Score, EQ-5D, and patient satisfaction. A Bayesian model averaging approach was used to build the best predictive model for dissatisfaction. Multiple logistic regression techniques were applied to quantify the effect size of the best model. RESULTS: At 6 months following THA, 95.4% of patients (n = 2000) were satisfied with surgical outcome and 4.6% (n = 96) were dissatisfied. The only variable that was significantly associated with dissatisfaction after THA was "complications after discharge." This result was consistent for both the complete and imputed dataset (odds ratio 4.78, 95% confidence interval 2.60-8.80, P < 0.001 and odds ratio 3.8, 95% confidence interval 2.60-5.60, P < 0.001, respectively). CONCLUSION: Our study confirms the high rates of patient satisfaction following THA, with postoperative complications being the only determinant of dissatisfaction. Optimization of patients prior to surgery, reducing postoperative complications, may further improve satisfaction rates after THA.

Cerebral Hyperperfusion Syndrome Presenting As Status Epilepticus Following Carotid Endarterectomy.

Cerebral Hyperperfusion Syndrome (CHS) is a rare syndrome, commonly described as a prodrome of symptoms including a severe ipsilateral headache, focal neurological deficits, intracerebral hemorrhage, and occasionally includes seizures or encephalopathy. Our case involves a 76-year-old man who underwent a left carotid endarterectomy (CEA) for symptomatic high-grade stenosis of his left carotid artery. Post-operative day one, the patient was seen and examined in the early morning and found to be doing well, with blood pressures well-controlled and at his neurologic baseline. Three hours later, he was reported to have a sudden spike in his blood pressure and was experiencing focal motor seizures involving the right arm and face, both of which were unrelieved by anti-hypertensives and anti-seizure medications. The patient subsequently developed worsening respiratory function requiring intubation for status epilepticus. Repeat head and neck imaging with CT, CT angiography, and MRI demonstrated the known previous subacute infarct with new cerebral edema, patent carotid arteries bilaterally, and no acute infarct or intracerebral hemorrhage. While CHS is a rare syndrome with well-documented symptomatology, we present a unique case in which focal motor status epilepticus was the only presenting symptom in a patient who otherwise meets the criteria of CHS based on radiographic evidence of cerebral edema following an elective CEA.

Trunk, pelvis and lower limb walking biomechanics are similarly altered in those with femoroacetabular impingement syndrome regardless of cam morphology size.

BACKGROUND: Studies of walking in those with femoroacetabular impingement syndrome have found altered pelvis and hip biomechanics. But a whole body, time-contiuous, assessment of biomechanical parameters has not been reported. Additionally, larger cam morphology has been associated with more pain, faster progression to end-stage osteoarthritis and increased cartilage damage but differences in walking biomechanics between large compared to small cam morphologies have not been assessed. RESEARCH QUESTION: Are trunk, pelvis and lower limb biomechanics different between healthy pain-free controls and individuals with FAI syndrome and are those biomechanics different between those with larger, compared to smaller, cam morphologies? METHODS: Twenty four pain-free controls were compared against 41 participants with FAI syndrome who were stratified into two groups according to their maximum alpha angle. Participants underwent three-dimensional motion capture during walking. Trunk, pelvis, and lower limb biomechanics were compared between groups using statistical parametric mapping corrected for walking speed and pain. RESULTS: Compared to pain-free controls, participants with FAI syndrome walked with more trunk anterior tilt (mean difference 7.6°, p < 0.001) as well as less pelvic rise (3°, p < 0.001), hip abduction (-4.6°, p < 0.05) and external rotation (-6.5°, p < 0.05). They also had lower hip flexion (-0.06Nm⋅kg-1, p < 0.05), abduction (-0.07Nm⋅kg-1, p < 0.05) and ankle plantarflexion moments (-0.19Nm⋅kg-1, p < 0.001). These biomechanical differences occurred throughout the gait cycle. There were no differences in walking biomechanics according to cam morphology size. SIGNIFICANCE: Results do not support the hypothesis that larger cam morphology is associated with larger differences in walking biomechanics but did demonstrate general differences in trunk, pelvis and lower limb biomechanics between those with FAI sydrome and pain-free controls. Altered external biomechanics are likely the result of complex sensory-motor strategy resulting from pain inhibition or impingement avoidance. Future studies should examine internal loading in those with FAI sydnrome.

Does soft tissue balancing using intraoperative pressure sensors improve clinical outcomes in total knee arthroplasty? A protocol of a multicentre randomised controlled trial.

INTRODUCTION: Soft tissue imbalance is considered to be a major surgical cause of dissatisfaction following total knee arthroplasty (TKA). Surgeon-determined manual assessment of ligament tension has been shown to be a poor determinant of the true knee balance state. The recent introduction of intraoperative sensors, however, allows surgeons to precisely quantify knee compartment pressures and tibiofemoral kinematics, thereby optimising coronal and sagittal plane soft tissue balance. The primary hypothesis of this study is that achieving knee balance with use of sensors in TKA will improve patient-reported outcomes when compared with manual balancing. METHODS AND ANALYSIS: A multicentred, randomised controlled trial will compare patient-reported outcomes in 222 patients undergoing TKA using sensor-guided balancing versus manual balancing. The sensor will be used in both arms for purposes of data collection; however, surgeons will be blinded to the pressure data in patients randomised to manual balancing. The primary outcome will be the change from baseline to 1 year postoperatively in the mean of the four subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS4) that are most specific to TKA recovery: pain, symptoms, function and knee-related quality of life. Secondary outcomes will include the surgeon's capacity to determine knee balance, radiographic and functional measures and additional patient-reported outcomes. Normality of data will be assessed, and a Student's t-test and equivalent non-parametric tests will be used to compare differences in means among the two groups. ETHICS AND DISSEMINATION: Ethics approval was obtained from South Eastern Sydney Local Health District, Approval (HREC/18/POWH/320). Results of the trial will be presented at orthopaedic surgical meetings and submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ACTRN#12618000817246.

Image intensifier distortion influences a surgeon's ability to aim guidewires during orthopaedic procedures.

OBJECTIVE: Accurate insertion of a guidewire under image intensifier guidance is a fundamental skill required by orthopaedic surgeons. This study investigated how image intensifier distortion, which is composed of pin-cushion and sigmoidal components, changed the apparent trajectory of a guidewire, and the resulting deviation between the intended and actual guidewire tip position. MATERIALS AND METHODS: Intraoperative image intensifier images for 220 consecutive patients with hip fractures were retrospectively corrected for distortion using a global polynomial method. The deviation between the intended and actual guidewire tip positions was calculated. Additional distortion parameters were tested using an image intensifier produced by a different manufacturer, and a flat-panel c-arm. RESULTS: Deviation was approximately 1 cm if the guidewire was aimed from the extremity of the image and almost 0 if the entry point was only 20% from the centre (p < 0.001). The direction of deviation was different for left and right hips, with average deviations measuring 3 mm proximal and 5 mm distal respectively (p < 0.001). The flat-panel c-arm almost completely eliminated distortion. CONCLUSIONS: Image intensifier distortion significantly altered the intended trajectory of a guidewire, with guidewires aimed from the image periphery more affected than guidewires aimed from the centre. Furthermore, for right hips, guidewires should be aimed distal to their intended position, and for left hips they should be aimed proximal to achieve their desired position. The flat-panel c-arm eliminated the effect of distortion; hence, it may be preferable if precision in guidewire positioning is vital.

Comprehensive Multicenter Graduate Surgical Education Initiative Incorporating Entrustable Professional Activities, Continuous Quality Improvement Cycles, and a Web-Based Platform to Enhance Teaching and Learning.

BACKGROUND: It is increasingly important for faculty to teach deliberately and provide timely, detailed, and formative feedback on surgical trainee performance. We initiated a multicenter study to improve resident evaluative processes and enhance teaching and learning behaviors while engaging residents in their education. STUDY DESIGN: Faculty from 7 US postgraduate training programs rated resident operative performances using the perioperative briefing, intraoperative teaching, debriefing model, and rated patient visits/academic performances using the entrustable professional activities model via a web-based platform. Data were centrally analyzed and iterative changes made based on participant feedback, individual preferences, and database refinements, with trends addressed using the Plan, Do, Check, Act improvement methodology. RESULTS: Participants (92 surgeons, 150 residents) submitted 3,880 assessments during July 2014 through September 2017. Evidence of preoperative briefings improved from 33.9% ± 2.5% to 95.5% ± 1.5% between April and September 2014 compared with April and September 2017 (p < 0.001). Postoperative debriefings improved from 10.6% ± 2.7% to 90.2% ± 2.5% (p < 0.001) for the same period. Meaningful self-reflection by residents improved from 28.6% to 67.4% (p < 0.001). The number of assessments received per resident during a 6-month period increased from 6.4 ± 6.2 to 13.4 ± 10.1 (p < 0.003). Surgeon-entered assessments increased from 364 initially to 685 in the final period, and the number of resident assessments increased from 308 to 445. We showed a 4-fold increase in resident observed activities being rated. CONCLUSIONS: By adopting recognized educational models with repeated Plan, Do, Check, Act cycles, we increased the quality of preoperative learning objectives, showed more frequent, detailed, and timely assessments of resident performance, and demonstrated more effective self-reflection by residents. We monitored trends, identified opportunities for improvement and successfully sustained those improvements over time, applying a team-based approach.

Magnetic resonance imaging of the posterior cruciate ligament in flexion.

BACKGROUND: Posterior cruciate ligament (PCL) injuries of the knee are common and sometimes difficult to diagnose. Magnetic resonance imaging (MRI), performed using standard orthogonal plane views, is the investigation of choice. It can be particularly difficult to differentiate acute partial and complete tears and identify elongation of chronic healed tears. The aim of the paper is to describe a new method of positioning the patient with the knee flexed at 90°, allowing the PCL to be visualised in a position of greatest length and tension which may assist in differentiating and identifying these injuries. METHODS: Four symptomatic patients with suspected PCL injuries, two acute and two chronic, were MRI scanned using a routine protocol with the knee in extension before performing oblique sagittal fast spin-echo (FSE) proton-density (PD) sequences with the knee positioned in 90° of flexion. The appearance of the PCLs were then qualitatively assessed. RESULTS: MRI scanning with the knee in flexion identified more extensive PCL injury than standard imaging. In the two patients with acute injuries, partial tears on the standard orthogonal plane views were found to be complete ruptures. In the two patients with chronic injuries, elongation of the PCL not identifiable on the standard orthogonal plane views was apparent. CONCLUSION: MRI scanning of the PCL with the knee flexed at 90° may help in differentiating partial and complete ruptures of the PCL and identifying elongation of the PCL in chronic injuries.