In recent literature, the fragility index (FI) has been used to evaluate the robustness of statistically significant findings of dichotomous outcomes. This metric is defined as the minimum number of outcome events to flip study conclusions from significant to nonsignificant. Orthopaedics literature is frequently found to be fragile with a median FI of 2 in 150 RCTs across spine, hand, sports medicine, trauma and orthopaedic oncology studies. While many papers discuss limitations of FI, we aimed to further characterize it by introducing the Fragility Likelihood (FL), a new metric that allows us to consider the probability of the event to occur and to calculate the likelihood of this fragility to be reached. We systematically reviewed all randomized controlled trials in the Journal of Bone and Joint Surgery (Am) over 10 years. The FL was calculated with the following formula: A x B x C x 100% (A= FI; B = probability of the event in the group with the smallest number of events; C= probability of the non-event in the group with the highest number of events). A smaller FL demonstrates more robust results and conversely, a larger FL illustrates a higher likelihood of fragility being reached and more fragile the findings. The median FI for the statistically significant outcomes was 2 (Mean: 3.8; Range 0-23). The median FL for the statistically significant outcomes was 11% (Mean: 22%, Range: 2%-73%). This means that the probability of reaching non-significance is only 11% when considering the probability of the event to occur. When comparing studies with the same FI we found the FL to range from 3% to 43%. This illustrates the large differences in robustness between trials with equal FI when the likelihood of the event was taken into consideration. As orthopaedic studies are frequently reported as fragile, we found that by calculating the FL, studies may be more robust than previously assumed based off FI alone. By using the FL in conjunction with FI and p-values will provide additional insight into the robustness of the reported outcomes. Our results indicate that by calculating the FL, study conclusions are stronger than what the FI alone predicts. Although conducting RCTs in surgery can be challenging, we must endeavor to critically evaluate our results so we can answer important orthopaedic questions with certainty

Approximately 20% of patients feel unsatisfied 12 months after primary total knee arthroplasty (TKA). Current predictive tools for TKA focus on the clinician as the intended user rather than the patient. The aim of this study is to develop a tool that can be used by patients without clinician assistance, to predict health-related quality of life (HRQoL) outcomes 12 months after total knee arthroplasty (TKA). All patients with primary TKAs for osteoarthritis between 2012 and 2019 at a tertiary institutional registry were analysed. The predictive outcome was improvement in Veterans-RAND 12 utility score at 12 months after surgery. Potential predictors included patient demographics, co-morbidities, and patient reported outcome scores at baseline. Logistic regression and three machine learning algorithms were used. Models were evaluated using both discrimination and calibration metrics. Predictive outcomes were categorised into deciles from 1 being the least likely to improve to 10 being the most likely to improve. 3703 eligible patients were included in the analysis. The logistic regression model performed the best in out-of-sample evaluation for both discrimination (AUC = 0.712) and calibration (gradient = 1.176, intercept = -0.116, Brier score = 0.201) metrics. Machine learning algorithms were not superior to logistic regression in any performance metric. Patients in the lowest decile (1) had a 29% probability for improvement and patients in the highest decile (10) had an 86% probability for improvement. Logistic regression outperformed machine learning algorithms in this study. The final model performed well enough with calibration metrics to accurately predict improvement after TKA using deciles. An ongoing randomised controlled trial (ACTRN12622000072718) is evaluating the effect of this tool on patient willingness for surgery. Full results of this trial are expected to be available by April 2023. A free-to-use online version of the tool is available at . smartchoice.org.au.

Swelling following an ankle fracture is commonly believed to preclude surgical fixation, delaying operative treatment to allow the swelling to subside. This is in an attempt to achieve better soft tissue outcomes. We aim to identify whether pre-operative ankle swelling influences postoperative wound complications following ankle fracture surgery. This is a prospective cohort study of 80 patients presenting to a tertiary referral centre with operatively managed malleolar ankle fractures. Ankle swelling was measured visually and then quantitatively using the validated ‘Figure-of-eight’ technique. Follow-up was standardised at 2, 6, and 12 weeks post-operatively. Wound complications, patient co-morbidities, operative time, surgeon experience, and hospital stay duration were recorded. The complication rate was 8.75% (n=7), with 1 deep infection requiring operative intervention and all others resolving with oral antibiotics and wound cares. There was no significant difference in wound complication rates associated with quantitative ankle swelling (p=0.755), visual assessment of ankle swelling (p=0.647), or time to operative intervention (p=0.270). Increasing age (p=0.006) and female gender (p=0.049) had a significantly greater probability of wound complications. However, BMI, smoking status, level of the operating surgeon, and tourniquet time were not significantly different. Visual assessment of ankle swelling had a poor to moderate correlation to ‘Figure-of-eight’ ankle swelling measurements ICC=0.507 (0.325- 0.653). Neither ankle swelling nor time to surgery correlates with an increased risk of postoperative wound complication in surgically treated malleolar ankle fractures. Increasing patient age and female gender had a significantly greater probability of wound infection, irrespective of swelling. Visual assessment of ankle swelling is unreliable for quantifying true ankle swelling. Operative intervention at any time after an ankle fracture, irrespective of swelling, is safe and showed no better or worse soft tissue outcomes than those delayed for swelling

Aim. An instrumented blood culture system automatically flags when growth within the culture medium has been detected (‘work in progress’), and subsequently when the organism has been identified. We explore using this data to switch patients to oral therapy within 72 hours post-surgery, reducing costs and improving antimicrobial stewardship. Method. This retrospective review focused on clinically significant culture-positive bone and joint infections over a 5-month period in 2022. Two cohorts were defined as either having positive intraoperative microbiology at <72 hours or at ≥72 hours. Results. 150 patients were included. 133/150(88%) exhibited microbial growth <72hours. Of these, 98/133(74%) had all organisms identified <72-hours, and 34/133(26%) had additional organisms ≥72 hours. 19/151(12%) patients had their first positive cultures ≥72hrs from sampling. The most common isolates identified within 72 hours were S. aureus(30%), Enterobacteriaceae (26%), and Coagulase-negative Staphylococcus (CoNS)(19%). If no growth was observed by 48 hours, there was a 69.6% probability that subsequent growth wouldn't occur; this probability increases to 81.9% by 72 hours, 88.7% by 96 hours, 91.0% by 120 hours, and 95.0% by 144 hours (see figure 1). The most common isolates identified ≥72 hours were CoNS(28%), Cutibacterium acnes(16%) and S. aureus(12%). Assessing oral antibiotic regimes for isolates identified after 72 hours demonstrated that linezolid would cover isolates from 96% of patients, tetracyclines 92% of patients, clindamycin 85% of patients, and ciprofloxacin and rifampicin would cover 80% of patients. Vancomycin and meropenem, our standard empirical therapy, gave the best cover at 96% of patients. Conclusions. This study suggests there is sufficient microbiological information at 72 hours for most patients to allow transition to a targeted regimen. If there has been no detection of growth when using an instrumented blood culture system by 72 hours, it is likely that there will be no growth. For any tables or figures, please contact the authors directly

Aims. The risk to patients and healthcare workers of resuming elective orthopaedic surgery following the peak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been difficult to quantify. This has prompted governing bodies to adopt a cautious approach that may be impractical and financially unsustainable. The lack of evidence has made it impossible for surgeons to give patients an informed perspective of the consequences of elective surgery in the presence of SARS-CoV-2. This study aims to determine, for the UK population, the probability of a patient being admitted with an undetected SARS-CoV-2 infection and their resulting risk of death; taking into consideration the current disease prevalence, reverse transcription-polymerase chain reaction (RT-PCR) testing, and preassessment pathway. Methods. The probability of SARS-CoV-2 infection with a false negative test was calculated using a lower-end RT-PCR sensitivity of 71%, specificity of 95%, and the UK disease prevalence of 0.24% reported in May 2020. Subsequently, a case fatality rate of 20.5% was applied as a worst-case scenario. Results. The probability of SARS-CoV-2 infection with a false negative preoperative test was 0.07% (around 1 in 1,400). The risk of a patient with an undetected infection being admitted for surgery and subsequently dying from the coronavirus disease 2019 (COVID-19) is estimated at approximately 1 in 7,000. However, if an estimate of the current global infection fatality rate (1.04%) is applied, the risk of death would be around 1 in 140,000, at most. This calculation does not take into account the risk of nosocomial infection. Conversely, it does not factor in that patients will also be clinically assessed and asked to self-isolate prior to surgery. Conclusion. Our estimation suggests that the risk of patients being inadvertently admitted with an undetected SARS-CoV-2 infection for elective orthopaedic surgery is relatively low. Accordingly, the risk of death following elective orthopaedic surgery is low, even when applying the worst-case fatality rate. Cite this article: Bone Joint J 2020;102-B(9):1256–1260

Primary hip and knee joint replacements in Canada have been estimated to cost over $1.4 billion dollars annually, with revision surgery costing $177 million. The most common cause of revision arthroplasty surgery in Canada is infection. Periprosthetic joint infections (PJIs) are a devastating though preventable complication following arthroplasty. Though variably used, antibiotic laden bone cement (ALBC) has been demonstrated to decrease PJIs following primary total knee arthroplasty (TKA). Unfortunately, ALBC is costlier than regular bone cement (RBC). Therefore, the aim of this study was to determine if the routine use of ALBC in primary TKA surgery is a cost-effective practice from the perspective of the Canadian healthcare system. A decision tree was constructed using a decision analysis software (TreeAge Software, Williamstown, Massachusetts) to a two-year time horizon comparing primary TKA with either ALBC or RBC from the perspective of a single-payer healthcare system. All costs were in 2020 Canadian dollars. Health utilities were in the form of quality adjusted life years (QALYs). Model inputs for cost were derived from regional and national databases. Health utilities and probability parameters were derived from the latest literature. One-way deterministic sensitivity analysis was performed on all model parameters. The primary outcome of this analysis was an incremental cost-effectiveness ratio (ICER) with a willingness-to-pay (WTP) threshold of $50,000 per QALY. Primary TKA with ALBC (TKA-ALBC) was found to be more cost-effective compared to primary TKA with RBC (TKA-RBC). More specifically, TKA-ALBC dominated TKA-RBC as it was less costly on the long term ($11,160 vs. $11,118), while providing the same QALY (1.66). The ICER of this cost-utility analysis (CUA) was $-11,049.72 per QALY, much less than the WTP threshold of $50,000 per QALY. The model was sensitive to costs of ALBC-TKA as well as the probability of PJI following ALBC-TKA and RBC-TKA. ALBC ceased to be cost effective once the cost of ALBC was greater than $223.08 CAD per bag of cement. The routine use of ALBC in primary TKA is a cost-effective practice in the context of the Canadian healthcare system as long as the cost of ALBC is maintained at a reasonable price and the published studies to-date keep supporting the efficacy of ALBC in decreasing PJI following primary TKA. Further, this analysis is very conservative, and ALBC is likely much more cost-effective than presented. This is due to this model's revision surgery cost parameter being based on the average cost of all revision TKA surgery in Canada, regardless of etiology. Considering many PJIs require two-stage revisions, the cost parameter used in this analysis for revision surgery is an underestimate of true cost. Ultimately, this is the first cost-effectiveness study evaluating this topic from the perspective of the Canadian healthcare system and can inform future national guidelines on the subject matter

Tourniquet use in total knee arthroplasty (TKA) remains a subject of considerable debate. A recent study questioned the need for tourniquets based on associated risks. However, the study omitted analysis of crucial tourniquet-related parameters which have been demonstrated in numerous studies to be associated with safe tourniquet use and reduction of adverse events. The current utilization and preferences of tourniquet use in Canada remain unknown. Our primary aim was to determine the current practices, patterns of use, and opinions of tourniquet use in TKA among members of the Canadian Arthroplasty Society (CAS). Additionally, we sought to determine the need for updated best practice guidelines to inform optimal tourniquet use and to identify areas requiring further research. A self-administered survey was emailed to members of the CAS in October 2021(six-week period). The response rate was 57% (91/161). Skip logic branching was used to administer a maximum of 59 questions related to tourniquet use, beliefs, and practices. All respondents were staff surgeons and 88% were arthroplasty fellowship trained. Sixty-five percent have been in practice for ≥11 years and only 16% for 50 TKA/year, 59% have an academic practice, and >67% prefer cemented TKA. Sixty-six percent currently use tourniquets, 25% no longer do but previously did, and 9% never used tourniquets. For those not using tourniquets, the most common reasons are potential harm/risks and publications/conferences. Among current users, 48% use in all cases and an additional 37% use in 76-99% of cases. The top reason for use was improved visualization/bloodless field (88%), followed by performing a cemented TKA, used in training, and faster operative times. The main patient factor influencing selective tourniquet use was peripheral vascular disease and main surgical factors were operative duration and cementless TKA. The most frequent adverse events reported were bruising/pinching under the tourniquet and short-term pain, which majority believed were related to improper tourniquet use (prolonged time, high-pressures, poor cuff fit), yet only 8% use contoured tourniquets and 32% don't use limb protection. Despite substantial evidence in literature that tourniquet safety and probability of harm are affected by tourniquet time and pressure, only 83% and 72% of respondents believe reducing tourniquet time and pressure respectively reduce the probability of harm. In addition, no surgeon utilizes personalized limb occlusion pressure which has been demonstrated to substantially reduce tourniquet pressure while being safe and effective. Furthermore, 62% always use fixed pressure and 37% will modify the pressure based on patient parameters, most often systolic blood pressure and limb size. Almost all (88%) were interested in new evidence-based guidelines regarding these parameters. Tourniquet use in TKA remains prevalent among arthroplasty surgeons in the CAS; however tremendous practice variability regarding several key parameters required for optimal use exists. Current best practices of tourniquet use regarding personalized pressures, time, and type are not being utilized across Canada. There is considerable interest and need for further research and updated guidelines regarding key parameters of safe tourniquet usage to optimize tourniquet use in TKA

External validation of machine learning predictive models is achieved through evaluation of model performance on different groups of patients than were used for algorithm development. This important step is uncommonly performed, inhibiting clinical translation of newly developed models. Recently, machine learning was used to develop a tool that can quantify revision risk for a patient undergoing primary anterior cruciate ligament (ACL) reconstruction (https://swastvedt.shinyapps.io/calculator_rev/). The source of data included nearly 25,000 patients with primary ACL reconstruction recorded in the Norwegian Knee Ligament Register (NKLR). The result was a well-calibrated tool capable of predicting revision risk one, two, and five years after primary ACL reconstruction with moderate accuracy. The purpose of this study was to determine the external validity of the NKLR model by assessing algorithm performance when applied to patients from the Danish Knee Ligament Registry (DKLR). The primary outcome measure of the NKLR model was probability of revision ACL reconstruction within 1, 2, and/or 5 years. For the index study, 24 total predictor variables in the NKLR were included and the models eliminated variables which did not significantly improve prediction ability - without sacrificing accuracy. The result was a well calibrated algorithm developed using the Cox Lasso model that only required five variables (out of the original 24) for outcome prediction. For this external validation study, all DKLR patients with complete data for the five variables required for NKLR prediction were included. The five variables were: graft choice, femur fixation device, Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life subscale score at surgery, years from injury to surgery, and age at surgery. Predicted revision probabilities were calculated for all DKLR patients. The model performance was assessed using the same metrics as the NKLR study: concordance and calibration. In total, 10,922 DKLR patients were included for analysis. Average follow-up time or time-to-revision was 8.4 (±4.3) years and overall revision rate was 6.9%. Surgical technique trends (i.e., graft choice and fixation devices) and injury characteristics (i.e., concomitant meniscus and cartilage pathology) were dissimilar between registries. The model produced similar concordance when applied to the DKLR population compared to the original NKLR test data (DKLR: 0.68; NKLR: 0.68-0.69). Calibration was poorer for the DKLR population at one and five years post primary surgery but similar to the NKLR at two years. The NKLR machine learning algorithm demonstrated similar performance when applied to patients from the DKLR, suggesting that it is valid for application outside of the initial patient population. This represents the first machine learning model for predicting revision ACL reconstruction that has been externally validated. Clinicians can use this in-clinic calculator to estimate revision risk at a patient specific level when discussing outcome expectations pre-operatively. While encouraging, it should be noted that the performance of the model on patients undergoing ACL reconstruction outside of Scandinavia remains unknown

Introduction. A common acute orthopaedic presentation is an ulcerated or infected foot secondary to diabetic neuropathy. Surgical debridement or amputation are often required to manage this complication of diabetes. International literature indicates that amputation may lead to further complications and an increased mortality rate. The aim of this study is to investigate the mortality rate associated with different surgical interventions. This will inform surgical management of patients presenting with acute foot complications from diabetes. Methods. This is a retrospective review of patients with diabetic foot infections aged >16 years attending Middlemore Hospital over a 10-year period (2012–2021). Clinical records were examined to determine whether patients were managed with no surgery, surgery but not amputation, or amputation. We recorded relevant baseline characteristics and comorbidities. Regression models were used to determine factors associated with mortality. Results. Over the study period, 1260 patients were included in analysis. Patients were divided into three groups, a control group who received no surgical intervention (n=554), those receiving surgery but not amputation (n=269), and those who underwent amputation (n=437). After adjustment for potential confounders, mortality rates were significantly higher in those who underwent amputation compared with those who received surgical intervention without amputation. Survival probability at 1 year and 5 years was highest in the surgical intervention but not amputation group. Conclusion. It is clinically important that there is a lower mortality rate in patients who undergo surgical intervention without amputation. Treatment that aims to salvage the limb rather than amputate should be considered in management of patients with diabetic foot complications to optimise their care

While pre-soaking grafts in vancomycin has demonstrated to be effective in observational studies for anterior cruciate ligament reconstruction (ACLR) infection prevention, the economic benefit of the technique is uncertain. The primary aim of this study was to determine the cost-effectiveness of vancomycin pre-soaking during primary ACLR to prevent post-operative joint infections. The secondary aims of the study were to establish the breakeven cost-effectiveness threshold of the technique. A Markov model was used to determine cost effectiveness and the incremental cost effectiveness ratio of additional vancomycin pre-soaking compared to intravenous antibiotic prophylaxis alone. A repeated meta-analysis of nine cohort studies (Level III evidence) was completed to determine the odds ratio of infection with vancomycin pre-soaking compared to intravenous antibiotics alone. Estimated costs and transitional probabilities for further surgery were obtained from the literature. Breakeven threshold analysis was performed. The vancomycin soaking technique provides an expected cost saving of $600AUD per patient. There was an improvement in the quality-adjusted life years of 0.007 compared to intravenous antibiotic prophylaxis alone (4.297 versus 4.290). If the infection rate is below 0.023% with intravenous antibiotics alone or the additional intervention cost more than $1000AUD, the vancomycin wrap would no longer be cost-effective. For $30AUD, the vancomycin soaking technique provides a $600AUD cost saving by both reducing the risk of ACLR related infection and economic burden of infection. Treating septic arthritis represents a mean cost per patient of 6 times compared to that of the primary surgery. There has been no previous cost-effectiveness study of the vancomycin wrap technique. The vancomycin pre-soaking technique is a highly cost-effective method to prevent post-operative septic arthritis following primary ACLR

Aim. Ankle fracture surgery comes with a risk of fracture-related infection (FRI). Identifying risk factors are important in preoperative planning, in management of patients, and for information to the individual patient about their risk of complications. In addition, modifiable factors can be addressed prior to surgery. The aim of the current paper was to identify risk factors for FRI in patients operated for ankle fractures. Method. A cohort of 1004 patients surgically treated for ankle fractures at Haukeland University hospital in the period of 2015–2019 was studied retrospectively. Patient charts and radiographs were assessed for the diagnosis of FRI. Binary logistic regression was used in analyses of risk factors. Regression coefficients were used to calculate the probability for FRI based on the patients’ age and presence of one or more risk factors. Results. FRI was confirmed in 87 (9%) of 1004 patients. Higher age at operation (p < 0.001), congestive heart failure (CHF), p = 0.006), peripheral artery disease (PAD, p = 0.001), and current smoking (p = .006) were identified as risk factors for FRI. PAD and CHF were the risk factors displaying the strongest association with FRI with an adjusted odds ratio of 4.2 (95% CI 1.8–10.1) and 4.7 (95% CI 1.6–14.1) respectively. Conclusions. The prevalence of FRI was 9% after surgical treatment of ankle fractures. The combination of risk factors found in this study demonstrate the need for a thorough, multidisciplinary, and careful approach when faced with an elderly or frail patient with an ankle fracture. The results of this study help the treating surgeons to inform their patients of the risk of FRI prior to ankle fracture surgery

Aims. The principles of evidence-based medicine (EBM) are the foundation of modern medical practice. Surgeons are familiar with the commonly used statistical techniques to test hypotheses, summarize findings, and provide answers within a specified range of probability. Based on this knowledge, they are able to critically evaluate research before deciding whether or not to adopt the findings into practice. Recently, there has been an increased use of artificial intelligence (AI) to analyze information and derive findings in orthopaedic research. These techniques use a set of statistical tools that are increasingly complex and may be unfamiliar to the orthopaedic surgeon. It is unclear if this shift towards less familiar techniques is widely accepted in the orthopaedic community. This study aimed to provide an exploration of understanding and acceptance of AI use in research among orthopaedic surgeons. Methods. Semi-structured in-depth interviews were carried out on a sample of 12 orthopaedic surgeons. Inductive thematic analysis was used to identify key themes. Results. The four intersecting themes identified were: 1) validity in traditional research, 2) confusion around the definition of AI, 3) an inability to validate AI research, and 4) cautious optimism about AI research. Underpinning these themes is the notion of a validity heuristic that is strongly rooted in traditional research teaching and embedded in medical and surgical training. Conclusion. Research involving AI sometimes challenges the accepted traditional evidence-based framework. This can give rise to confusion among orthopaedic surgeons, who may be unable to confidently validate findings. In our study, the impact of this was mediated by cautious optimism based on an ingrained validity heuristic that orthopaedic surgeons develop through their medical training. Adding to this, the integration of AI into everyday life works to reduce suspicion and aid acceptance. Cite this article: Bone Jt Open 2023;4(9):696–703

Introduction. Innovations in surgical robotics and navigation have significantly improved implant placement accuracy in total knee arthroplasty (TKA). However, many comparative studies have not been shown to substantially improve revision rates or other clinical outcome scores. We conducted a simulation study based on the reported distribution of patient-specific characteristics and estimated potential effect of coronal plane alignment (CPA) on risk of revision to evaluate the hypothesis that most published study designs in this area have been too underpowered to detect improvements in revision rates. Methods. To model previously reported studies, we generated a series of simulated TKA patient populations, assigning each patient a set of patient-specific factors (age at index surgery, BMI, and sex (Fig.1a)), as well as one surgeon-controlled factor (CPA) (Fig.1b) based on registry data and published literature. We modelled the survival probability for an individual patient at time t as a Gaussian function (exp[-(t/(k∗τ. max. )). 2. ]), where τ. max. (99.5 years) is selected to ensure the mean survival probability of the patient population matched 92% at 15 years. The value of k was adjusted for simulated patients within a range of 0 to 1 as a function of their patient and surgeon-specific factors (Fig.2). To evaluate power associated with a study design, we ran a Monte Carlo simulation generating 10,000 simulated populations of ten different cohort sizes. We divided the patient population into two groups: one group was assigned CPAs governed by the precision of a navigated/robotic approach (σ=1.5°), and the other CPAs governed by the precision of a conventional approach (σ=3°). We then simulated the time to failure for each patient, computed the corresponding Kaplan-Meier survival curves, and applied a Log-Rank test to each study to test for statistical difference. From the 10,000 simulations associated with each cohort size, we determined the percentage of simulated studies that found a statistically significant difference at each time point. Results. Figure 3 shows a contour plot illustrating the probability that a survival analysis with a specific study design would find statistical significance between the conventional and navigated/robotic patient groups. Entries from recently published literature are overlaid for context. No studies achieved statistical significance (p<0.05). Discussion. The effectiveness of navigated/robotic surgery is one of the most controversial debates in orthopedic surgery. The results from this simulation suggest that most revision studies aiming to settle this debate are likely significantly underpowered, falling below the normal 80% threshold. Limitations of this analysis include using only a single surgeon-controlled variable in the survival simulation, and only a single precision for the navigated/robotic approaches. Further studies will include more implant-related risk factors and a wider range of precisions for navigated/robotic procedures. Based on this simulation, it appears the effect size afforded by navigated/robotic surgeries on revision rates in TKA surgery is too small to recommend broad application, especially since adoption could involve added costs and unforeseen risks associated with novelty. Clinically, it may be beneficial to examine the use of robotics/navigation on high-risk patients, where studies are likely to have higher power due to larger effect sizes. For any figures or tables, please contact the authors directly

Aims. Sickle cell disease (SCD) is an autosomal recessive inherited condition that presents with a number of clinical manifestations that include musculoskeletal manifestations (MM). MM may present differently in different individuals and settings and the predictors are not well known. Herein, we aimed at determining the predictors of MM in patients with SCD at the University Teaching Hospital, Lusaka, Zambia. Methods. An unmatched case-control study was conducted between January and May 2019 in children below the age of 16 years. In all, 57 cases and 114 controls were obtained by systematic sampling method. A structured questionnaire was used to collect data. The different MM were identified, staged, and classified according to the Standard Orthopaedic Classification Systems using radiological and laboratory investigations. The data was entered in Epidata version 3.1 and exported to STATA 15 for analysis. Multiple logistic regression was used to determine predictors and predictive margins were used to determine the probability of MM. Results. The cases were older median age 9.5 (interquartile range (IQR) 7 to 12) years compared to controls 7 (IQR 4 to 11) years; p = 0.003. After multivariate logistic regression, increase in age (adjusted odds ratio (AOR) = 1.2, 95% confidence interval (CI) 1.04 to 1.45; p = 0.043), increase in the frequency of vaso-occlusive crisis (VOC) (AOR = 1.3, 95% CI 1.09 to 1.52; p = 0.009) and increase in percentage of haemoglobin S (HbS) (AOR = 1.18, 95% CI 1.09 to 1.29; p < 0.001) were significant predictors of MM. Predictive margins showed that for a 16-year-old the average probability of having MM would be 51 percentage points higher than that of a two-year-old. Conclusion. Increase in age, frequency of VOC, and an increase in the percentage of HbS were significant predictors of MM. These predictors maybe useful to clinicians in determining children who are at risk. Cite this article: Bone Joint Open 2020;1-6:175–181

Iliopsoas tendonitis occurs in up to 30% of patients after hip resurfacing arthroplasty (HRA) and is a common reason for revision. The primary purpose of this study was to validate our novel computational model for quantifying iliopsoas impingement in HRA patients using a case-controlled investigation. Secondary purpose was to compare these results with previously measured THA patients. We conducted a retrospective search in an experienced surgeon's database for HRA patients with iliopsoas tendonitis, confirmed via the active hip flexion test in supine, and control patients without iliopsoas tendonitis, resulting in two cohorts of 12 patients. The CT scans were segmented, landmarked, and used to simulate the iliopsoas impingement in supine and standing pelvic positions. Three discrete impingement values were output for each pelvic position, and the mean and maximum of these values were reported. Cup prominence was measured using a novel, nearest-neighbour algorithm. The mean cup prominence for the symptomatic cohort was 10.7mm and 5.1mm for the asymptomatic cohort (p << 0.01). The average standing mean impingement for the symptomatic cohort was 0.1mm and 0.0mm for the asymptomatic cohort (p << 0.01). The average standing maximum impingement for the symptomatic cohort was 0.2mm and 0.0mm for the asymptomatic cohort (p << 0.01). Impingement significantly predicted the probability of pain in logistic regression models and the simulation had a sensitivity of 92%, specificity of 91%, and an AUC ROC curve of 0.95. Using a case-controlled investigation, we demonstrated that our novel simulation could detect iliopsoas impingement and differentiate between the symptomatic and asymptomatic cohorts. Interestingly, the HRA patients demonstrated less impingement than the THA patients, despite greater cup prominence. In conclusion, this tool has the potential to be used preoperatively, to guide decisions about optimal cup placement, and postoperatively, to assist in the diagnosis of iliopsoas tendonitis

Human error is usually evaluated using statistical descriptions during radiographic annotation. The technological advances popularized the “non-human” landmarking techniques, such as deep learning, in which the error is presented in a confidence format that is not comparable to that of the human method. The region-based landmark definition makes an arbitrary “ground truth” point impossible. The differences in patients’ anatomies, radiograph qualities, and scales make the horizontal comparison difficult. There is a demand to quantify the manual landmarking error in a probability format. Taking the measurement of pelvic tilt (PT) as an example, this study recruited 115 sagittal pelvic radiographs for the measurement of two PTs. We proposed a method to unify the scale of images that allows horizontal comparisons of landmarks and calculated the maximum possible error using a density vector. Traditional descriptive statistics were also applied. All measurements showed excellent reliabilities (intraclass correlation coefficients > 0.9). Eighty-four measurements (6.09%) were qualified as wrong landmarks that failed to label the correct locations. Directional bias (systematic error) was identified due to cognitive differences between observers. By removing wrong labels and rotated pelves, the analysis quantified the error density as a “good doctor” performance and found 6.77°-11.76° maximum PT disagreement with 95% data points. The landmarks with excellent reliability still have a chance (at least 6.09% in our case) of making wrong landmark decisions. Identifying skeletal contours is at least 24.64% more accurate than estimating landmark locations. The landmark at a clear skeletal contour is more likely to generate systematic errors. Due to landmark ambiguity, a very careful surgeon measuring PT could make a maximum 11.76° random difference in 95% of cases, serving as a “good doctor benchmark” to qualify good landmarking techniques

Several different algorithms attempt to estimate life expectancy for patients with metastatic spine disease. The Skeletal Oncology Research Group (SORG) has recently developed a nomogram to estimate survival of patients with metastatic spine disease. Whilst the use of the SORG nomogram has been validated in the international context, there has been no study to date that validates the use of the SORG nomogram in New Zealand. This study aimed to validate the use of the SORG nomogram in Aotearoa New Zealand. We collected data on 100 patients who presented to Waikato Hospital with a diagnosis of spinal metastatic disease. The SORG nomogram gave survival probabilities for each patient at each time point. Receiver Operating Characteristic (ROC) Area Under Curve (AUC) analysis was performed to assess the predictive accuracy of the SORG score. A calibration curve was also performed, and Brier scores calculated. A multivariate Cox regression analysis was performed. The SORG score was correlated with 30 day (AUC = 0.72) and 90-day mortality (AUC = 0.71). The correlation between the SORG score and 90-day mortality was weaker (AUC = 0.69). Using this method, the nomogram was correct for 79 (79%) patients at 30-days, 59 patients (59%) at 90-days, and 42 patients (42%) at 365-days. Calibration curves demonstrated poor forecasting of the SORG nomogram at 30 (Brier score = 0.65) and 365 days (Brier score = 0.33). The calibration curve demonstrated borderline forecasting of the SORG nomogram at 90 days (Brier score = 0.28). Several components of the SORG nomogram were not found to be correlated with mortality. In this New Zealand cohort the SORG nomogram demonstrated only acceptable discrimination at best in predicting life 30-, 90- or 356-day mortality in patients with metastatic spinal disease

Aim. Prosthetic joint infection (PJI) is assessed using clinical history and examination, imaging studies and laboratory investigations which inform diagnostic tools such as that proposed by the European Bone and Joint Infection Society to determine the probability of infection. Infection is often confirmed by microbiology culture and histology from intraoperative samples, but ideally a diagnosis of infection is made preoperatively to guide management decisions. At our institution, a tertiary referral centre for PJI, ultrasound (US)-guided synovial biopsy is routinely used as an adjunct to preoperative joint aspiration. Our aim was to evaluate the sensitivity and specificity of microbiology and histology results from US-guided synovial biopsy samples when compared to intraoperative samples. Method. In this retrospective study we analysed all prosthetic hip and knee US-guided biopsies performed at our institution over a 5 year period between 2018 and 2022. Microbiology and histology results from preoperative biopsy samples were individually compared to microbiology and histology findings from intraoperative samples. Results. 381 biopsies were performed; 281 knee, 100 hip. US-guided biopsy results showed strong positive predictive values (PPVs) in hip biopsies (microbiology PPV (79.3%), histology PPV (85.7%)) and knee biopsies (microbiology PPV (77%), histology PPV (85%)). Biopsies showed low sensitivity in predicting intraoperative findings (hip microbiology sensitivity (62%), hip histology sensitivity (31%), knee microbiology sensitivity (70%), knee histology sensitivity (21%). Biopsies showed high specificity for knee (microbiology specificity (89%), histology specificity (97%)) and hip (microbiology specificity (73%), histology specificity (91%)). Conclusions. This study demonstrates that US-guided biopsy is a valuable diagnostic aid for PJI with high specificities and PPVs. Furthermore US-biopsy is valuable when there is limited fluid for aspiration

The diagnosis of infection following shoulder arthroplasty is notoriously difficult. The prevalence of prosthetic shoulder infection after arthroplasty ranges from 3.9 – 15.4% and the most common infective organism is Cutibacterium acnes. Current preoperative diagnostic tests fail to provide a reliable means of diagnosis including WBC, ESR, CRP and joint aspiration. Fluoroscopic-guided percutaneous synovial biopsy (PSB) has previously been reported in the context of a pilot study and demonstrated promising results. The purpose of this study was to determine the diagnostic accuracy of percutaneous synovial biopsy compared with open culture results (gold standard). This was a multicenter prospective cohort study involving four sites and 98 patients who underwent revision shoulder arthroplasty. The cohort was 60% female with a mean age was 65 years (range 36-83 years). Enrollment occurred between June 2014 and November 2021. Pre-operative fluoroscopy-guided synovial biopsies were carried out by musculoskeletal radiologists prior to revision surgery. A minimum of five synovial capsular tissue biopsies were obtained from five separate regions in the shoulder. Revision shoulder arthroplasty was performed by fellowship-trained shoulder surgeons. Intraoperative tissue samples were taken from five regions of the joint capsule during revision surgery. Of 98 patients who underwent revision surgery, 71 patients underwent both the synovial biopsy and open biopsy at time of revision surgery. Nineteen percent had positive infection based on PSB, and 22% had confirmed culture positive infections based on intra-operative tissue sampling. The diagnostic accuracy of PSB compared with open biopsy results were as follows: sensitivity 0.37 (95%CI 0.13-0.61), specificity 0.81 (95%CI 0.7-0.91), positive predictive value 0.37 (95%CI 0.13 – 0.61), negative predictive value 0.81 (95%CI 0.70-0.91), positive likelihood ratio 1.98 and negative likelihood ratio 0.77. A patient with a positive pre-operative PSB undergoing revision surgery had an 37% probability of having true positive infection. A patient with a negative pre-operative PSB has an 81% chance of being infection-free. PSB appears to be of value mainly in ruling out the presence of peri-prosthetic infection. However, poor likelihood ratios suggest that other ancillary tests are required in the pre-operative workup of the potentially infected patient

Aim. Irrigation and debridement with an irrigation solution are essential components of the surgical management of acute and chronic periprosthetic joint infection (PJI). Nevertheless, there is a lack of agreement regarding the most effective solution to use. The aim of the study was to perform a systematic review and meta-analysis of the current literature concerning the efficacy of different irrigation solutions over bacterial biofilm. Method. This study was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis extension for Network meta-analysis (PRISMA-NMA) checklist for systematic reviews and meta-analyses. A comprehensive literature search of PubMed, Cochrane Library, Web of Science and Scopus databases from inception to September 1, 2023. We combined terms related to PJI, biofilm and irrigation solutions studied in vitro. We performed a network meta-analysis to analyze which irrigation solution achieved a higher reduction of colony forming units (CFU) after specific exposure times, always with a maximum of five minutes, replicating intraoperative conditions. Effect-size was summarized with logarithmic response ratio (logRR) and 95% confidence intervals (95% CI). The rank probability for each treatment was calculated using the p-scores. Results. We screened 233 potential sources. Following deduplication, screening and full-text review, four studies with ten irrigation solutions for different duration of exposures were included, always less than five minutes, replicating intraoperative conditions. Solutions were studied over mature biofilms of most frequent bacteria grown over metal, bone cement or polyethylene surfaces. The highest effect was achieved with povidone iodine 10% during 5 minutes (logRR: −12.02; 95% CI: −14.04, −9.99). The best ranked solutions were povidone iodine 10% during five, three and one minute (respective p-scores: 0.977, 0.932, 0.887) and its combination with hydrogen peroxide for 3 minutes (p-score: 0.836). Povidone iodine 0.3% acting for 5 minutes completed the top 5 best ranked solutions in this study (p-score: 0.761). We assumed that there were no inconsistencies in our network because after examining both scenarios, with and without inconsistencies, the results were not significantly different. Conclusions. Our results show that 10% povidone-iodine is the best antiseptic solution when studied in vitro in the context of prosthetic joint infection. However, the included studies did not evaluate the possible cytotoxic effects of these solutions. This should also be taken into account before choosing the most appropriate antiseptic solution