Aims. The aim of this study was to review the value of accepting referrals for children with ‘clicky hips’ in a selective screening programme for hip dysplasia. Patients and Methods. A single-centre prospective database of all referrals to the hip clinic was examined to identify indication for referrals, diagnosis, and treatment. All patients referred received a standardized ultrasound scan and clinical examination by an orthopaedic consultant. Results. There were 5716 children referred to the orthopaedic hip clinic between 1 June 2014 and 26 September 2018. In all, 1754 children (30.1%) were referred due to ‘clicky hip’ with no additional risk factors or indications for ultrasound scan. A total of 123 children (7.1%) referred with ‘clicky hip’ and no additional risk factors or examination findings had an abnormal initial hip ultrasound, including 16 children (0.9%) with dysplastic hips. Of the 141 children who required treatment in a Pavlik harness during the study period, 23 (16%) had been referred with a ‘clicky hip’ and no additional risk factors or examination findings, including six children with Graf 3 or 4 hips. Conclusion. There is significant value in reviewing children with an isolated ‘clicky hip’. Many children who require treatment are referred to the orthopaedic service as ‘clicky hip’ with no additional risk factors. In a pragmatic pathway with a diverse population of clinicians performing baby checks, ‘clicky hip’ is an important indication for referral and should not be discarded. Cite this article: Bone Joint J 2019;101-B:635–638

Aims. Current American Academy of Orthopaedic Surgeons (AAOS) guidelines for treating femoral fractures in children aged two to six years recommend early spica casting although some individuals have recommended intramedullary stabilization in this age group. The purpose of this study was to compare the treatment and family burden of care of spica casting and flexible intramedullary nailing in this age group. Methods. Patients aged two to six years old with acute, non-pathological femur fractures were prospectively enrolled at one of three tertiary children’s hospitals. Either early closed reduction with spica cast application or flexible intramedullary nailing was accomplished under general anaesthesia. The treatment method was selected after discussion of the options by the surgeon with the family. Data were prospectively collected on patient demographics, fracture characteristics, complications, pain medication, and union. The Impact on Family Scale was obtained at the six-week follow-up visit. In all, 75 patients were included in the study: 39 in the spica group and 36 in the nailing group. The mean age of the spica group was 2.71 (2.0 to 6.9) years and the mean age of the nailing group was 3.16 (2.0 to 6.9) years. Results. All fractures healed without evidence of malunion or more than 2.0 cm of shortening. The mean Impact on Family score was 70.2 for the spica group and 63.2 (55 to 99) for the nailing group, a statistically significant difference (p = 0.024) in a univariate analysis suggesting less impairment of the family in the intramedullary nailing group. There was no significant difference between pain medication requirements in the first 24 hours postoperatively. Two patients in the spica group and one patient in the intramedullary nailing group required additional treatment under anaesthesia. Conclusion. Both early spica casting and intramedullary nailing were effective methods for treating femoral fractures in children two to six years of age. Intramedullary stabilization provides an option in this age group that may be advantageous in some social situations that depend on the child’s mobility. Fracture treatment should be individualized based on factors that extend beyond anatomical and biological factors. Cite this article: Bone Joint J 2020;102-B(8):1056–1061

Aims. The Wrightington classification system of fracture-dislocations of the elbow divides these injuries into six subtypes depending on the involvement of the coronoid and the radial head. The aim of this study was to assess the reliability and reproducibility of this classification system. Methods. This was a blinded study using radiographs and CT scans of 48 consecutive patients managed according to the Wrightington classification system between 2010 and 2018. Four trauma and orthopaedic consultants, two post CCT fellows, and one speciality registrar based in the UK classified the injuries. The seven observers reviewed preoperative radiographs and CT scans twice, with a minimum four-week interval. Radiographs and CT scans were reviewed separately. Inter- and intraobserver reliability were calculated using Fleiss and Cohen kappa coefficients. The Landis and Koch criteria were used to interpret the strength of the kappa values. Validity was assessed by calculating the percentage agreement against intraoperative findings. Results. Of the 48 patients, three (6%) had type A injury, 11 (23%) type B, 16 (33%) type B+, 16 (33%) Type C, two (4%) type D+, and none had a type D injury. All 48 patients had anteroposterior (AP) and lateral radiographs, 44 had 2D CT scans, and 39 had 3D reconstructions. The interobserver reliability kappa value was 0.52 for radiographs, 0.71 for 2D CT scans, and 0.73 for a combination of 2D and 3D reconstruction CT scans. The median intraobserver reliability was 0.75 (interquartile range (IQR) 0.62 to 0.79) for radiographs, 0.77 (IQR 0.73 to 0.94) for 2D CT scans, and 0.89 (IQR 0.77 to 0.93) for the combination of 2D and 3D reconstruction. Validity analysis showed that accuracy significantly improved when using CT scans (p = 0.018 and p = 0.028 respectively). Conclusion. The Wrightington classification system is a reliable and valid method of classifying fracture-dislocations of the elbow. CT scans are significantly more accurate than radiographs when identifying the pattern of injury, with good intra- and interobserver reproducibility. Cite this article: Bone Joint J 2020;102-B(8):1041–1047

Aims. Short, bone-conserving femoral components are increasingly used in total hip arthroplasty (THA). They are expected to allow tissue-conserving implantation and to render future revision surgery more straightforward but the long-term data on such components is limited. One such component is the global tissue-sparing (GTS) stem. Following the model for stepwise introduction of new orthopaedic implants, we evaluated early implant fixation and clinical outcome of this novel short-stem THA and compared it to that of a component with established good long-term clinical outcome. Methods. In total, 50 consecutive patients ≤ 70 years old with end-stage symptomatic osteo-arthritis were randomized to receive THA with the GTS stem or the conventional Taperloc stem using the anterior supine intermuscular approach by two experienced hip surgeons in two hospitals in the Netherlands. Primary outcome was implant migration. Patients were followed using routine clinical examination, patient reported outcome using Harris Hip Score (HHS), Hip Disability And Osteoarthritis Outcome Score (HOOS), EuroQol five-dimension questionnaire (EQ5D), and Roentgen Stereophotogrammetric Analysis (RSA) at three, six, 12, and 24 months. This study evaluated the two-year follow-up results. Results. In addition to the initial migration pattern of distal migration (subsidence, Y-translation) and retroversion (Y-rotation) also exhibited by the Taperloc stem, the GTS stem showed an initial migration pattern of varization (X-translation combined with Z-rotation) and posterior translation (Z-translation). However, all components stabilized aside from one Taperloc stem which became loose secondary to malposition and was later revised. Clinical outcomes and complications were not statistically significantly different with the numbers available. Conclusion. A substantially different and more extensive initial migration pattern was seen for the GTS stem compared to the Taperloc stem. Although implant stabilization was achieved, excellent long-term survival similar to that of the Taperloc stem should not be inferred. Especially in the absence of clinically proven relevant improvement, widespread usage should be postponed until long-term safety has been established. Cite this article: Bone Joint J 2020;102-B(6):699–708

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

Aims. Slipped capital femoral epiphysis (SCFE) is one of the most common hip diseases of adolescence that can cause marked disability, yet there is little robust evidence to guide treatment. Fundamental aspects of the disease, such as frequency, are unknown and consequently the desire of clinicians to undertake robust intervention studies is somewhat prohibited by a lack of fundamental knowledge. Methods. The study is an anonymized nationwide comprehensive cohort study with nested consented within the mechanism of the British Orthopaedic Surgery Surveillance (BOSS) Study. All relevant hospitals treating SCFE in England, Scotland, and Wales will contribute anonymized case details. Potential missing cases will be cross-checked against two independent external sources of data (the national administrative data and independent trainee data). Patients will be invited to enrich the data collected by supplementing anonymized case data with patient-reported outcome measures. In line with recommendations of the IDEAL Collaboration, the study will primarily seek to determine incidence, describe case mix and variations in surgical interventions, and explore the relationships between baseline factors (patients and types of interventions) and two-year outcomes. Discussion. This is the first disease to be investigated using the BOSS Study infrastructure. It provides a robust method to determine the disease frequency, and a large unbiased sample of cases from which treatment strategies can be investigated. It may form the basis for definitive robust intervention studies or, where these are demonstrated not to be feasible, this may be the most robust cohort study

Aims. Infected and deformed neuropathic feet and ankles are serious challenges for surgical management. In this study we present our experience in performing ankle arthrodesis in a closed manner, without surgical preparation of the joint surfaces by cartilaginous debridement, but instead using an Ilizarov ring fixator (IRF) for deformity correction and facilitating fusion, in arthritic neuropathic ankles with associated osteomyelitis. Methods. We retrospectively reviewed all the patients who underwent closed ankle arthrodesis (CAA) in Ilizarov Scientific Centre from 2013 to 2018 (Group A) and compared them with a similar group of patients (Group B) who underwent open ankle arthrodesis (OAA). We then divided the neuropathic patients into three arthritic subgroups: Charcot joint, Charcot-Maire-Tooth disease, and post-traumatic arthritis. All arthrodeses were performed by using an Ilizarov ring fixator. All patients were followed up clinically and radiologically for a minimum of 12 months to assess union and function. Results. The union rate for Group A was 81% (17/21) while it was 84.6% (33/39) for Group B. All the nonunions in Group A underwent revision with an open technique and achieved 100% union. Mean duration of IRF was 71.5 days (59 to 82) in Group A and 69 days (64.8 to 77.7) in Group B. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was similar in both groups. The postoperative hospital stay was shorter in Group A (21 days (SD 8)) than Group B (28 days (SD 9)). In the latter Group there were more problems with wound healing and greater requirement for antibiotic treatment. The mean operating time was 40 minutes (SD 9) in Group A compared to 80 minutes (SD 13) in Group B. Recurrence of infection occurred in 19% (4/21) and 15.5% (6/39) for Group A and Group B respectively. Conclusion. We found CAA using an IRF to be an effective method for ankle arthrodesis in infected neuropathic foot and ankle cases and afforded comparable results to open methods. Due to its great advantages, Ilizarov method of CAA should always be considered for neuropathic ankles in suitable patients. Cite this article: Bone Joint J 2020;102-B(4):470–477

Aims. The purpose of this study was to identify prognostic indicators of outcome at presentation to the orthopaedic surgeon, in patients with metastatic prostate cancer. Our aim was to use this information in a pragmatic, clinic-based approach so that surgical decision making could be optimized to benefit the patient in their remaining lifetime. Patients and Methods. A cohort analysis was undertaken of all patients with metastatic disease of the prostate who presented to a regional orthopaedic centre in the United Kingdom between 2003 and 2016. Biochemical data were collected in addition to disease and demographic data. These included: prostate-specific antigen (PSA) at orthopaedic presentation; haemoglobin (Hb); platelets (plt); alkaline phosphatase (ALP); albumin (Alb); and corrected calcium (CaC). Statistical analysis included Kaplan–Meier survival analysis, and a Cox proportional hazards model was fitted to the data. Results. From the departmental database, 137 episodes were identified in 136 patients with a median age at presentation of 72 years (interquartile range (IQR) 66 to 78). Most patients had stage IV disease (n = 98, 72%), and most did not undergo surgical intervention. At one-year follow-up, 50% of patients had died. Biomarkers found to be independently associated with poor survival were: low Hb, low Alb, relatively low PSA (< 30 mmol/l), and a raised ALP. Patients who needed surgical intervention had a poorer survival rate than patients who were managed nonoperatively. Conclusion. The study findings are important for orthopaedic clinical practice in the management of patients with metastatic prostate cancer. The interpretation of routine blood tests can help to predict survival in patients who present with orthopaedic manifestations of prostate cancer. A lower PSA is not necessarily a good prognostic sign. We believe that simple blood testing should be carried out routinely when assessing a patient, guiding potential surgical management and palliative care in the future

Aims. Metabolic profiling is a top-down method of analysis looking at metabolites, which are the intermediate or end products of various cellular pathways. Our primary objective was to perform a systematic review of the published literature to identify metabolites in human synovial fluid (HSF), which have been categorized by metabolic profiling techniques. A secondary objective was to identify any metabolites that may represent potential biomarkers of orthopaedic disease processes. Methods. A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines using the MEDLINE, Embase, PubMed, and Cochrane databases. Studies included were case series, case control series, and cohort studies looking specifically at HSF. Results. The primary analysis, which pooled the results from 17 published studies and four meeting abstracts, identified over 200 metabolites. Seven of these studies (six published studies, one meeting abstract) had asymptomatic control groups and collectively suggested 26 putative biomarkers in osteoarthritis, inflammatory arthropathies, and trauma. These can broadly be categorized into amino acids plus related metabolites, fatty acids, ketones, and sugars. Conclusion. The role of metabolic profiling in orthopaedics is fast evolving with many metabolites already identified in a variety of pathologies. However, these results need to be interpreted with caution due to the presence of multiple confounding factors in many of the studies. Future research should include largescale epidemiological metabolic profiling studies incorporating various confounding factors with appropriate statistical analysis to account for multiple testing of the data. Cite this article:Bone Joint Res. 2020;9(3):108–119

Implant-related infection is one of the leading reasons for failure in orthopaedics and trauma, and results in high social and economic costs. Various antibacterial coating technologies have proven to be safe and effective both in preclinical and clinical studies, with post-surgical implant-related infections reduced by 90% in some cases, depending on the type of coating and experimental setup used. Economic assessment may enable the cost-to-benefit profile of any given antibacterial coating to be defined, based on the expected infection rate with and without the coating, the cost of the infection management, and the cost of the coating. After reviewing the latest evidence on the available antibacterial coatings, we quantified the impact caused by delaying their large-scale application. Considering only joint arthroplasties, our calculations indicated that for an antibacterial coating, with a final user’s cost price of €600 and able to reduce post-surgical infection by 80%, each year of delay to its large-scale application would cause an estimated 35 200 new cases of post-surgical infection in Europe, equating to additional hospital costs of approximately €440 million per year. An adequate reimbursement policy for antibacterial coatings may benefit patients, healthcare systems, and related research, as could faster and more affordable regulatory pathways for the technologies still in the pipeline. This could significantly reduce the social and economic burden of implant-related infections in orthopaedics and trauma. Cite this article: C. L. Romanò, H. Tsuchiya, I. Morelli, A. G. Battaglia, L. Drago. Antibacterial coating of implants: are we missing something? Bone Joint Res 2019;8:199–206. DOI: 10.1302/2046-3758.85.BJR-2018-0316

Aims. In a randomized controlled trial with two-year follow-up, patients treated with suture button (SB) for acute syndesmotic injury had better outcomes than patients treated with syndesmotic screw (SS). The aim of this study was to compare clinical and radiological outcomes for these treatment groups after five years. Methods. A total of 97 patients with acute syndesmotic injury were randomized to SS or SB. The five-year follow-up rate was 81 patients (84%). The primary outcome was the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Scale. Secondary outcome measures included Olerud-Molander Ankle (OMA) score, visual analogue scale (VAS), EuroQol five-dimension questionnaire (EQ-5D), range of movement, complications, reoperations, and radiological results. CT scans of both ankles were obtained after surgery, and after one, two, and five years. Results. The SB group had higher median AOFAS score (100 (interquartile range (IQR) 92 to 100) vs 90 (IQR 85 to 100); p = 0.006) and higher median OMA score (100 (IQR 95 to 100) vs 95 (IQR 75 to 100); p = 0.006). The SS group had a higher incidence of ankle osteoarthritis (OA) (24 (65%) vs 14 (35%), odds ratio (OR) 3.4 (95% confidence interval (CI) 1.3 to 8.8); p = 0.009). On axial CT we measured a significantly smaller mean difference in the anterior tibiofibular distance between injured and non-injured ankles in the SB group (–0.1 mm vs 1.2 mm; p = 0.016). Conclusion. Five years after syndesmotic injury treated with either SB or SS, we found better AOFAS and OMA scores, and lower incidence of ankle OA, in the SB group. These long-term results favour the use of SB when treating an acute syndesmotic injury. Cite this article: Bone Joint J 2020;102-B(2):212–219

Aims. Trochlear dysplasia is a significant risk factor for patellofemoral instability. The Dejour classification is currently considered the standard for classifying trochlear dysplasia, but numerous studies have reported poor reliability on both plain radiography and MRI. The severity of trochlear dysplasia is important to establish in order to guide surgical management. We have developed an MRI-specific classification system to assess the severity of trochlear dysplasia, the Oswestry-Bristol Classification (OBC). This is a four-part classification system comprising normal, mild, moderate, and severe to represent a normal, shallow, flat, and convex trochlear, respectively. The purpose of this study was to assess the inter- and intraobserver reliability of the OBC and compare it with that of the Dejour classification. Methods. Four observers (two senior and two junior orthopaedic surgeons) independently assessed 32 CT and axial MRI scans for trochlear dysplasia and classified each according to the OBC and the Dejour classification systems. Assessments were repeated following a four-week interval. The inter- and intraobserver agreement was determined by using Fleiss’ generalization of Cohen’s kappa statistic and S-statistic nominal and linear weights. Results. The OBC showed fair-to-good interobserver agreement and good-to-excellent intraobserver agreement (mean kappa 0.68). The Dejour classification showed poor interobserver agreement and fair-to-good intraobserver agreement (mean kappa 0.52). Conclusion. The OBC can be used to assess the severity of trochlear dysplasia. It can be applied in clinical practice to simplify and standardize surgical decision-making in patients with recurrent patella instability. Cite this article: Bone Joint J 2020;102-B(1):102–107

Aims. The early mortality in patients with hip fractures from bony metastases is unknown. The objectives of this study were to quantify 30- and 90-day mortality in patients with proximal femoral metastases, and to create a mortality prediction tool based on biomarkers associated with early death. Methods. This was a retrospective cohort study of consecutive patients referred to the orthopaedic department at a UK trauma centre with a proximal femoral metastasis (PFM) over a seven-year period (2010 to 2016). The study group were compared to a matched control group of non-metastatic hip fractures. Minimum follow-up was one year. Results. There was a 90-day mortality of 46% in patients with metastatic hip fractures versus 12% in controls (89/195 and 24/192, respectively; p < 0.001). Mean time to surgery was longer in symptomatic metastases versus complete fractures (9.5 days (SD 19.8) and 3.4 days (SD 11.4), respectively; p < 0.05). Albumin, urea, and corrected calcium were all independent predictors of early mortality and were used to generate a simple tool for predicting 90-day mortality, titled the Metastatic Early Prognostic (MEP) score. An MEP score of 0 was associated with the lowest risk of death at 30 days (14%, 3/21), 90 days (19%, 4/21), and one year (62%, 13/21). MEP scores of 3/4 were associated with the highest risk of death at 30 days (56%, 5/9), 90 days (100%, 9/9), and one year (100%, 9/9). Neither age nor primary cancer diagnosis was an independent predictor of mortality at 30 and 90 days. Conclusion. This score could be used to predict early mortality and guide perioperative counselling. The delay to surgery identifies a potential window to intervene and correct these abnormalities with the aim of improving survival. Cite this article: Bone Joint J. 2020;102-B(1):72–81

Aims. To evaluate the donor site morbidity and tendon morphology after harvesting whole length, full-thickness peroneus longus tendon (PLT) proximal to the lateral malleolus for ligament reconstructions or tendon transfer. Methods. A total of 21 eligible patients (mean age 34.0 years (standard deviation (SD) 11.2); mean follow-up period 31.8 months (SD 7.7), and 12 healthy controls (mean age, 26.8 years (SD 5.9) were included. For patients, clinical evaluation of the donor ankle was performed preoperatively and postoperatively. Square hop test, ankle strength assessment, and MRI of distal calf were assessed bilaterally in the final follow-up. The morphological symmetry of peroneal tendons bilaterally was evaluated by MRI in healthy controls. Results. Among the patients, the mean pre- and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score and Karlsson-Peterson score were 98.7 (SD 2.5; p = 0.480) and 98.5 (SD 2.4; p = 0.480), and 98.3 (SD 2.4; p = 0.162) and 97.9 (SD 2.5; p = 0.162), respectively. There was no significant difference between square hop test bilaterally (p = 0.109) and plantar flexion peak force bilaterally (p = 0.371). The harvested limb had significantly less eversion peak force compared to the contralateral limb (p < 0.001). Evidence of probable tendon regeneration was observed in all the patients by MRI and the total bilateral peroneal tendon index (mean ratio of harvested side cross-sectional area of peroneal tendon compared with the contralateral side) was 82.9% (SD 17.4). In 12 healthy controls, peroneal tendons (mean 99.4% (SD 4.3) were found to be morphologically symmetrical between the two sides. Conclusion. The current study showed satisfactory clinical foot and ankle outcomes after full-thickness PLT harvesting and indicated the regenerative potential of PLT after its removal. Level of Evidence: Level IV, therapeutic retrospective case series. Cite this article: Bone Joint J 2020;102-B(2):205–211

Aims. Open fractures of the tibia are a heterogeneous group of injuries that can present a number of challenges to the treating surgeon. Consequently, few surgeons can reliably advise patients and relatives about the expected outcomes. The aim of this study was to determine whether these outcomes are predictable by using the Ganga Hospital Score (GHS). This has been shown to be a useful method of scoring open injuries to inform wound management and decide between limb salvage and amputation. Methods. We collected data on 182 consecutive patients with a type II, IIIA, or IIIB open fracture of the tibia who presented to our hospital between July and December 2016. For the purposes of the study, the patients were jointly treated by experienced consultant orthopaedic and plastic surgeons who determined the type of treatment. Separately, the study team (SP, HS, AD, JD) independently calculated the GHS and prospectively collected data on six outcomes for each patient. These included time to bony union, number of admissions, length of hospital stay, total length of treatment, final functional score, and number of operations. Spearman’s correlation was used to compare GHS with each outcome. Forward stepwise linear regression was used to generate predictive models based on components of the GHS. Five-fold cross-validation was used to prevent models from over-fitting. Results. The mean follow-up was 11.4 months (3 to 31). The mean time to union was 9.7 months (3 to 21), the mean number of operations was 2.8 (1 to 11), the mean time in hospital was 17.7 days (5 to 84), the mean length of treatment was 92.7 days (5 to 730), the mean number of admissions was 1.7 (1 to 6), and the mean functional score (Lower Extremity Functional Score (LEFS)) was 60.13 (33 to 80). There was a significant correlation between the GHS and each of the outcome measures. A predictive model was generated from which the GHS could be used to predict the various outcome measures. Conclusion. The GHS can be used to predict the outcome of patients who present with an open fracture of the tibia. Our model generates a numerical value for each outcome measure that can be used in clinical practice to inform the treating team and to advise patients. Cite this article: Bone Joint J 2020;102-B(1):26–32

Aim. There has been a significant reduction in unicompartmental knee arthroplasty (UKA) procedures recorded in Australia. This follows several national joint registry studies documenting high UKA revision rates when compared to total knee arthroplasty (TKA). With the recent introduction of robotically assisted UKA procedures, it is hoped that outcomes improve. This study examines the cumulative revision rate of UKA procedures implanted with a newly introduced robotic system and compares the results to one of the best performing non-robotically assisted UKA prostheses, as well as all other non-robotically assisted UKA procedures. Methods. Data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR) for all UKA procedures performed for osteoarthritis (OA) between 2015 and 2018 were analyzed. Procedures using the Restoris MCK UKA prosthesis implanted using the Mako Robotic-Arm Assisted System were compared to non-robotically assisted Zimmer Unicompartmental High Flex Knee System (ZUK) UKA, a commonly used UKA with previously reported good outcomes and to all other non-robotically assisted UKA procedures using Cox proportional hazard ratios (HRs) and Kaplan-Meier estimates of survivorship. Results. There was no difference in the rate of revision when the Mako-assisted Restoris UKA was compared to the ZUK UKA (zero to nine months: HR 1.14 (95% CI 0.71 to 1.83; p = 0.596) vs nine months and over: HR 0.66 (95% CI 0.42 to 1.02; p = 0.058)). The Mako-assisted Restoris had a significantly lower overall revision rate compared to the other types of non-robotically assisted procedures (HR 0.58 (95% confidence interval (CI) 0.42 to 0.79); p < 0.001) at three years. Revision for aseptic loosening was lower for the Mako-assisted Restoris compared to all other non-robotically assisted UKA (entire period: HR 0.34 (95% CI 0.17 to 0.65); p = 0.001), but not the ZUK prosthesis. However, revision for infection was significantly higher for the Mako-assisted Restoris compared to the two comparator groups (ZUK: entire period: HR 2.91 (95% CI 1.22 to 6.98; p = 0.016); other non-robotically assisted UKA: zero to three months: HR 5.57 (95% CI 2.17 to 14.31; p < 0.001)). Conclusion. This study reports comparable short-term survivorship for the Mako robotically assisted UKA compared to the ZUK UKA and improved survivorship compared to all other non-robotic UKA. These results justify the continued use and investigation of this procedure. However, the higher rate of early revision for infection for robotically assisted UKA requires further investigation. Cite this article: Bone Joint J 2020;102-B(3):319–328

Aims. Rotational acetabular osteotomy (RAO) is an effective joint-preserving surgical treatment for acetabular dysplasia. The purpose of this study was to investigate changes in muscle strength, gait speed, and clinical outcome in the operated hip after RAO over a one-year period using a standard protocol for rehabilitation. Patients and Methods. A total of 57 patients underwent RAO for acetabular dysplasia. Changes in muscle strength of the operated hip, 10 m gait speed, Japanese Orthopaedic Association (JOA) hip score, and factors correlated with hip muscle strength after RAO were retrospectively analyzed. Results. Three months postoperatively, the strength of the operated hip in flexion and abduction and gait speed had decreased from their preoperative levels. After six months, the strength of flexion and abduction had recovered to their preoperative level, as had gait speed. At one-year follow-up, significant improvements were seen in the strength of hip abduction and gait speed, but muscle strength in hip flexion remained at the preoperative level. The mean JOA score for hip function was 91.4 (51 to 100)) at one-year follow-up. Body mass index (BMI) showed a negative correlation with both strength of hip flexion (r = -0.4203) and abduction (r = -0.4589) one year after RAO. Although weak negative correlations were detected between strength of hip flexion one year after surgery and age (r = -0.2755) and centre-edge (CE) angle (r = -0.2989), no correlation was found between the strength of abduction and age and radiological evaluations of CE angle and acetabular roof obliquity (ARO). Conclusion. Hip muscle strength and gait speed had recovered to their preoperative levels six months after RAO. The clinical outcome at one year was excellent, although the strength of hip flexion did not improve to the same degree as that of hip abduction and gait speed. A higher BMI may result in poorer recovery of hip muscle strength after RAO. Radiologically, acetabular coverage did not affect the recovery of hip muscle strength at one year’s follow-up. A more intensive rehabilitation programme may improve this. Cite this article: Bone Joint J 2019;101-B:1459–1463

There is good scientific rationale to support the use of growth factors to promote musculoskeletal tissue regeneration. However, the clinical effectiveness of platelet-rich plasma (PRP) and other blood-derived products has yet to be proven. Characterization and reporting of PRP preparation protocols utilized in clinical trials for the treatment of musculoskeletal disease is highly inconsistent, and the majority of studies do not provide sufficient information to allow the protocols to be reproduced. Furthermore, the reporting of blood-derived products in orthopaedics is limited by the multiple PRP classification systems available, which makes comparison of results between studies challenging. Several attempts have been made to characterize and classify PRP; however, no consensus has been reached, and there is lack of a comprehensive and validated classification. In this annotation, we outline existing systems used to classify preparations of PRP, highlighting their advantages and limitations. There remains a need for standardized universal nomenclature to describe biological therapies, as well as a comprehensive and reproducible classification system for autologous blood-derived products. Cite this article: Bone Joint J 2019;101-B:891–896

Aims. High-quality clinical research in children’s orthopaedic surgery has lagged behind other surgical subspecialties. This study used a consensus-based approach to identify research priorities for clinical trials in children’s orthopaedics. Methods. A modified Delphi technique was used, which involved an initial scoping survey, a two-round Delphi process and an expert panel formed of members of the British Society of Children’s Orthopaedic Surgery. The survey was conducted amongst orthopaedic surgeons treating children in the United Kingdom and Ireland. Results. A total of 86 clinicians contributed to both rounds of the Delphi process, scoring priorities from one (low priority) to five (high priority). Elective topics were ranked higher than those relating to trauma, with the top ten elective research questions scoring higher than the top question for trauma. Ten elective, and five trauma research priorities were identified, with the three highest ranked questions relating to the treatment of slipped capital femoral epiphysis (mean score 4.6/ 5), Perthes’ disease (4.5) and bone infection (4.5). Conclusion. This consensus-based research agenda will guide surgeons, academics and funders to improve the evidence in children’s orthopaedic surgery and encourage the development of multicentre clinical trials. Cite this article: Bone Joint J 2018;100-B:680–4

Aims. The practice of alternating operating theatres has long been used to reduce surgeon idle time between cases. However, concerns have been raised as to the safety of this practice. We assessed the payments and outcomes of total knee arthroplasty (TKA) performed during overlapping and nonoverlapping days, also comparing the total number of the surgeon’s cases and the total time spent in the operating theatre per day. Materials and Methods. A retrospective analysis was performed on the Centers for Medicare & Medicaid Services (CMS) Limited Data Set (LDS) on all primary elective TKAs performed at the New England Baptist Hospital between January 2013 and June 2016. Using theatre records, episodes were categorized into days where a surgeon performed overlapping and nonoverlapping lists. Clinical outcomes, economic outcomes, and demographic factors were calculated. A regression model controlling for the patient-specific factors was used to compare groups. Total orthopaedic cases and aggregate time spent operating (time between skin incision and closure) were also compared. Results. A total of 3633 TKAs were performed (1782 on nonoverlapping days; 1851 on overlapping days). There were no differences between the two groups for length of inpatient stay, payments, mortality, emergency room visits, or readmission during the 90-day postoperative period. The overlapping group had 0.74 fewer skilled nursing days (95% confidence interval (CI) -0.26 to -1.22; p < 0.01), and 0.66 more home health visits (95% CI 0.14 to 1.18; p = 0.01) than the nonoverlapping group. On overlapping days, surgeons performed more cases per day (5.01 vs 3.76; p < 0.001) and spent more time operating (484.55 minutes vs 357.17 minutes; p < 0.001) than on nonoverlapping days. Conclusion. The study shows that the practice of alternating operating theatres for TKA has no adverse effect on the clinical outcome or economic utilization variables measured. Furthermore, there is opportunity to increase productivity with alternating theatres as surgeons with overlapping cases perform more cases and spend more time operating per day. Cite this article: Bone Joint J 2019;101-B:1081–1086