Objective. In ex vivo hip fracture studies femoral pairs are split to create two comparable test groups. When more than two groups are required, or if paired femurs cannot be obtained, group allocation according to bone mineral density (BMD) is sometimes performed. In this statistical experiment we explore how this affects experimental results and sample size considerations. Methods. In a hip fracture experiment, nine pairs of human cadaver femurs were tested in a paired study design. The femurs were then re-matched according to BMD, creating two new test groups. Intra-pair variance and paired correlations in fixation stability were calculated. A hypothetical power analysis was then performed to explore the required sample size for the two types of group allocation. . Results. The standard deviation (. sd. ) of the mean paired difference in fixation stability increased from 2 mm in donor pairs to 5 mm in BMD-matched pairs. Intra-pair correlation was 0.953 (Pearson’s r) in donor pairs and non-significant at -0.134 (Pearson’s r) in BMD-matched pairs. Required sample size to achieve a statistical power of 0.8 increased from ten pairs using donor pairs to 54 pairs using BMD-matched pairs. Conclusion. BMD cannot be used to create comparable test groups unless sample size is increased substantially and paired statistics are no longer valid. Cite this article: Bone Joint Res 2014;3:317–20

Aims. We aimed to evaluate the utility of . 68. Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with . 99m. Tc-methylene bisphosphonates (. 99m. Tc-MDP) bone scan. Methods. We studied 39 patients with suspected PJI or AL. These patients underwent . 68. Ga-citrate PET/CT, . 99m. Tc-MDP three-phase bone scan and single-photon emission CT (SPECT)/CT. PET/CT was performed at ten minutes and 60 minutes after injection, respectively. Images were evaluated by three nuclear medicine doctors based on: 1) visual analysis of the three methods based on tracer uptake model, and PET images attenuation-corrected with CT and those not attenuation-corrected with CT were analyzed, respectively; and 2) semi-quantitative analysis of PET/CT: maximum standardized uptake value (SUVmax) of lesions, SUVmax of the lesion/SUVmean of the normal bone, and SUVmax of the lesion/SUVmean of the normal muscle. The final diagnosis was based on the clinical and intraoperative findings, and histopathological and microbiological examinations. Results. Overall, 23 and 16 patients were diagnosed with PJI and AL, respectively. The sensitivity and specificity of three-phase bone scan and SPECT/CT were 100% and 62.5%, 82.6%, and 100%, respectively. Attenuation correction (AC) at 60 minutes and non-AC at 60 minutes of PET/CT had the same highest sensitivity and specificity (91.3% and 100%), and AC at 60 minutes combined with SPECT/CT could improve the diagnostic efficiency (sensitivity = 95.7%). Diagnostic efficacy of the SUVmax was low (area under the curve (AUC) of ten minutes and 60 minutes was 0.814 and 0.806, respectively), and SUVmax of the lesion/SUVmean of the normal bone at 60 minutes was the best semi-quantitative parameter (AUC = 0.969). Conclusion. 68. Ga-citrate showed the potential to differentiate PJI from AL, and visual analysis based on uptake pattern of tracer was reliable. The visual analysis method of AC at 60 minutes, combined with . 99m. Tc-MDP SPECT/CT, could improve the sensitivity from 91.3% to 95.7%. In addition, a major limitation of our study was that it had a limited sample size, and more detailed studies with a larger sample size are warranted. Cite this article: Bone Joint Res 2022;11(6):398–408

Aims. We aimed to determine the concentrations of synovial vancomycin and meropenem in patients treated by single-stage revision combined with intra-articular infusion following periprosthetic joint infection (PJI), thereby validating this drug delivery approach. Methods. We included 14 patients with PJI as noted in their medical records between November 2021 and August 2022, comprising eight hip and seven knee joint infections, with one patient experiencing bilateral knee infections. The patients underwent single-stage revision surgery, followed by intra-articular infusion of vancomycin and meropenem (50,000 µg/ml). Synovial fluid samples were collected to assess antibiotic concentrations using high-performance liquid chromatography. Results. The peak concentrations of vancomycin and meropenem in the joint cavity were observed at one hour post-injection, with mean values of 14,933.9 µg/ml (SD 10,176.3) and 5,819.1 µg/ml (SD 6,029.8), respectively. The trough concentrations at 24 hours were 5,495.0 µg/ml (SD 2,360.5) for vancomycin and 186.4 µg/ml (SD 254.3) for meropenem. The half-life of vancomycin was 6 hours, while that of meropenem ranged between 2 and 3.5 hours. No significant adverse events related to the antibiotic administration were observed. Conclusion. This method can achieve sustained high antibiotic concentrations within the joint space, exceeding the reported minimum biofilm eradication concentration. Our study highlights the remarkable effectiveness of intra-articular antibiotic infusion in delivering high intra-articular concentrations of antibiotics. The method provided sustained high antibiotic concentrations within the joint cavity, and no severe side-effects were observed. These findings offer evidence to improve clinical treatment strategies. However, further validation is required through studies with larger sample sizes and higher levels of evidence. Cite this article: Bone Joint Res 2024;13(10):535–545

Aims. To evaluate inducing osteoarthritis (OA) by surgical destabilization of the medial meniscus (DMM) in mice with and without a stereomicroscope. Methods. Based on sample size calculation, 70 male C57BL/6 mice were randomly assigned to three surgery groups: DMM aided by a stereomicroscope; DMM by naked eye; or sham surgery. The group information was blinded to researchers. Mice underwent static weightbearing, von Frey test, and gait analysis at two-week intervals from eight to 16 weeks after surgery. Histological grade of OA was determined with the Osteoarthritis Research Society International (OARSI) scoring system. Results. Surgical DMM with or without stereomicroscope led to decrease in the mean of weightbearing percentages (-20.64% vs -21.44%, p = 0.792) and paw withdrawal response thresholds (-21.35% vs -24.65%, p = 0.327) of the hind limbs. However, the coefficient of variation (CV) of weight-bearing percentages and paw withdrawal response thresholds in naked-eye group were significantly greater than that in the microscope group (19.82% vs 6.94%, p < 0.001; 21.85% vs 9.86%, p < 0.001). The gait analysis showed a similar pattern. Cartilage degeneration was observed in both DMM-surgery groups, evidenced by increased OARSI scores (summed score: 11.23 vs 11.43, p = 0.842), but the microscope group showed less variation in OARSI score than the naked-eye group (CV: 21.03% vs 32.44%; p = 0.032). Conclusion. Although surgical DMM aided by stereomicroscope is technically difficult, it produces a relatively more homogeneous OA model in terms of the discrete degree of pain behaviours and histopathological grading when compared with surgical DMM without stereomicroscope. Cite this article: Bone Joint Res 2022;11(8):518–527

Aims. This study aimed to evaluate the effectiveness of the induced membrane technique for treating infected bone defects, and to explore the factors that might affect patient outcomes. Methods. A comprehensive search was performed in PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases between 1 January 2000 and 31 October 2021. Studies with a minimum sample size of five patients with infected bone defects treated with the induced membrane technique were included. Factors associated with nonunion, infection recurrence, and additional procedures were identified using logistic regression analysis on individual patient data. Results. After the screening, 44 studies were included with 1,079 patients and 1,083 segments of infected bone defects treated with the induced membrane technique. The mean defect size was 6.8 cm (0.5 to 30). After the index second stage procedure, 85% (797/942) of segments achieved union, and 92% (999/1,083) of segments achieved final healing. The multivariate analysis with data from 296 patients suggested that older age was associated with higher nonunion risk. Patients with external fixation in the second stage had a significantly higher risk of developing nonunion, increasing the need for additional procedures. The autografts harvested from the femur reamer-irrigator-aspirator increased nonunion, infection recurrence, and additional procedure rates. Conclusion. The induced membrane technique is an effective technique for treating infected bone defects. Internal fixation during the second stage might effectively promote bone healing and reduce additional procedures without increasing infection recurrence. Future studies should standardize individual patient data prospectively to facilitate research on the affected patient outcomes. Cite this article: Bone Joint Res 2023;12(9):546–558

Aims. To fully verify the reliability and reproducibility of an experimental method in generating standardized micromotion for the rat femur fracture model. Methods. A modularized experimental device has been developed that allows rat models to be used instead of large animal models, with the aim of reducing systematic errors and time and money constraints on grouping. The bench test was used to determine the difference between the measured and set values of the micromotion produced by this device under different simulated loading weights. The displacement of the fixator under different loading conditions was measured by compression tests, which was used to simulate the unexpected micromotion caused by the rat’s ambulation. In vivo preliminary experiments with a small sample size were used to test the feasibility and effectiveness of the whole experimental scheme and surgical scheme. Results. The bench test showed that a weight loading < 500 g did not affect the operation of experimental device. The compression test demonstrated that the stiffness of the device was sufficient to keep the uncontrollable motion between fracture ends, resulting from the rat’s daily activities, within 1% strain. In vivo results on 15 rats prove that the device works reliably, without overburdening the experimental animals, and provides standardized micromotion reproductively at the fracture site according to the set parameters. Conclusion. Our device was able to investigate the effect of micromotion parameters on fracture healing by generating standardized micromotion to small animal models. Cite this article: Bone Joint Res 2021;10(11):714–722

Objectives. Evidence -based medicine (EBM) is designed to inform clinical decision-making within all medical specialties, including orthopaedic surgery. We recently published a pilot survey of the Canadian Orthopaedic Association (COA) membership and demonstrated that the adoption of EBM principles is variable among Canadian orthopaedic surgeons. The objective of this study was to conduct a broader international survey of orthopaedic surgeons to identify characteristics of research studies perceived as being most influential in informing clinical decision-making. Materials and Methods. A 29-question electronic survey was distributed to the readership of an established orthopaedic journal with international readership. The survey aimed to analyse the influence of both extrinsic (journal quality, investigator profiles, etc.) and intrinsic characteristics (study design, sample size, etc.) of research studies in relation to their influence on practice patterns. Results. A total of 353 surgeons completed the survey. Surgeons achieved consensus on the ‘importance’ of three key designs on their practices: randomised controlled trials (94%), meta-analyses (75%) and systematic reviews (66%). The vast majority of respondents support the use of current evidence over historical clinical training; however subjective factors such as journal reputation (72%) and investigator profile (68%) continue to influence clinical decision-making strongly. Conclusion. Although intrinsic factors such as study design and sample size have some influence on clinical decision-making, surgeon respondents are equally influenced by extrinsic factors such as investigator reputation and perceived journal quality. Cite this article: Dr M. Ghert. An international survey to identify the intrinsic and extrinsic factors of research studies most likely to change orthopaedic practice. Bone Joint Res 2016;5:130–136. DOI: 10.1302/2046-3758.54.2000578

Objective. Hip arthroscopy in the setting of hip dysplasia is controversial in the orthopaedic community, as the outcome literature has been variable and inconclusive. We hypothesise that outcomes of hip arthroscopy may be diminished in the setting of hip dysplasia, but outcomes may be acceptable in milder or borderline cases of hip dysplasia. Methods. A systematic search was performed in duplicate for studies investigating the outcome of hip arthroscopy in the setting of hip dysplasia up to July 2015. Study parameters including sample size, definition of dysplasia, outcomes measures, and re-operation rates were obtained. Furthermore, the levels of evidence of studies were collected and quality assessment was performed. Results. The systematic review identified 18 studies investigating hip arthroscopy in the setting of hip dysplasia, with 889 included patients. Criteria used by the studies to diagnose hip dysplasia and borderline hip dysplasia included centre edge angle in 72% of studies but the range of angles were quite variable. Although 89% of studies reported improved post-operative outcome scores in the setting of hip dysplasia, revision rates were considerable (14.1%), with 9.6% requiring conversion to total hip arthroplasty. Conclusion. The available orthopaedic literature suggests that although improved outcomes are seen in hip arthroscopy in the setting of hip dysplasia, there is a high rate of re-operation and conversion to total hip arthroplasty. Furthermore, the criteria used to define hip dysplasia vary considerably among published studies. Cite this article: M. Yeung, M. Kowalczuk, N. Simunovic, O. R. Ayeni. Hip arthroscopy in the setting of hip dysplasia: A systematic review. Bone Joint Res 2016;5:225–231. DOI: 10.1302/2046-3758.56.2000533

High-quality randomised controlled trials (RCTs) evaluating surgical therapies are fundamental to the delivery of evidence-based orthopaedics. Orthopaedic clinical trials have unique challenges; however, when these challenges are overcome, evidence from trials can be definitive in its impact on surgical practice. In this review, we highlight several issues that pose potential challenges to orthopaedic investigators aiming to perform surgical randomised controlled trials. We begin with a discussion on trial design issues, including the ethics of sham surgery, the importance of sample size, the need for patient-important outcomes, and overcoming expertise bias. We then explore features surrounding the execution of surgical randomised trials, including ethics review boards, the importance of organisational frameworks, and obtaining adequate funding. Cite this article: Bone Joint Res 2014;3:161–8

Objectives. To assess the responsiveness and ceiling/floor effects of the Forgotten Joint Score -12 and to compare these with that of the more widely used Oxford Hip Score (OHS) in patients six and 12 months after primary total hip arthroplasty. Methods. We prospectively collected data at six and 12 months following total hip arthroplasty from 193 patients undergoing surgery at a single centre. Ceiling effects are outlined with frequencies for patients obtaining the lowest or highest possible score. Change over time from six months to 12 months post-surgery is reported as effect size (Cohen’s d). Results. The mean OHS improved from 40.3 (. sd. 7.9) at six months to 41.9 (. sd. 7.2) at 12 months. The mean FJS-12 improved from 56.8 (. sd. 30.1) at six months to 62.1 (. sd. 29.0) at 12 months. At six months, 15.5% of patients reached the best possible score (48 points) on the OHS and 8.3% obtained the best score (100 points) on the FJS-12. At 12 months, this percentage increased to 20.8% for the OHS and to 10.4% for the FJS-12. In terms of the effect size (Cohen’s d), the change was d = 0.10 for the OHS and d = 0.17 for the FJS-12. Conclusions. The FJS-12 is more responsive to change between six and 12 months following total hip arthroplasty than is the OHS, with the measured ceiling effect for the OHS twice that of the FJS-12. The difference in effect size of change results in substantial differences in required sample size if aiming to detect change between these two time points. This has important implications for powering clinical trials with patient-reported measures as the primary outcome. Cite this article: Dr D. F. Hamilton. Responsiveness and ceiling effects of the Forgotten Joint Score-12 following total hip arthroplasty. Bone Joint Res 2016;5:87–91. DOI: 10.1302/2046-3758.53.2000480

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To investigate the optimal thresholds and diagnostic efficacy of commonly used serological and synovial fluid detection indexes for diagnosing periprosthetic joint infection (PJI) in patients who have rheumatoid arthritis (RA).

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The present study aimed to investigate whether patients with inflammatory bowel disease (IBD) undergoing joint arthroplasty have a higher incidence of adverse outcomes than those without IBD.

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The aim of this study was to create artificial intelligence (AI) software with the purpose of providing a second opinion to physicians to support distal radius fracture (DRF) detection, and to compare the accuracy of fracture detection of physicians with and without software support.

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The aims of this study were to identify and evaluate the current literature examining the prognostic factors which are associated with failure of total elbow arthroplasty (TEA).

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This study aimed to explore the biological and clinical importance of dysregulated key genes in osteoarthritis (OA) patients at the cartilage level to find potential biomarkers and targets for diagnosing and treating OA.

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A substantial fraction of patients undergoing knee arthroplasty (KA) or hip arthroplasty (HA) do not achieve an improvement as high as the minimal clinically important difference (MCID), i.e. do not achieve a meaningful improvement. Using three patient-reported outcome measures (PROMs), our aim was: 1) to assess machine learning (ML), the simple pre-surgery PROM score, and logistic-regression (LR)-derived performance in their prediction of whether patients undergoing HA or KA achieve an improvement as high or higher than a calculated MCID; and 2) to test whether ML is able to outperform LR or pre-surgery PROM scores in predictive performance.

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Femoroacetabular impingement (FAI) patients report exacerbation of hip pain in deep flexion. However, the exact impingement location in deep flexion is unknown. The aim was to investigate impingement-free maximal flexion, impingement location, and if cam deformity causes hip impingement in flexion in FAI patients.

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The effects of remnant preservation on the anterior cruciate ligament (ACL) and its relationship with the tendon graft remain unclear. We hypothesized that the co-culture of remnant cells and bone marrow stromal cells (BMSCs) decreases apoptosis and enhances the activity of the hamstring tendons and tenocytes, thus aiding ACL reconstruction.

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To investigate the efficacy of ethylenediaminetetraacetic acid-normal saline (EDTA-NS) in dispersing biofilms and reducing bacterial infections.

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Achilles tendon re-rupture (ATRR) poses a significant risk of postoperative complication, even after a successful initial surgical repair. This study aimed to identify risk factors associated with Achilles tendon re-rupture following operative fixation.