Aims. The aim of this study was to perform a systematic review and bias evaluation of the current literature to create an overview of risk factors for re-revision following revision total knee arthroplasty (rTKA). Methods. A systematic search of MEDLINE and Embase was completed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The studies were required to include a population of index rTKAs. Primary or secondary outcomes had to be re-revision. The association between preoperative factors and the effect on the risk for re-revision was also required to be reported by the studies. Results. The search yielded 4,847 studies, of which 15 were included. A majority of the studies were retrospective cohorts or registry studies. In total, 26 significant risk factors for re-revision were identified. Of these, the following risk factors were consistent across multiple studies: age at the time of index revision, male sex, index revision being partial revision, and index revision due to infection. Modifiable risk factors were opioid use, BMI > 40 kg/m. 2. , and anaemia. History of one-stage revision due to infection was associated with the highest risk of re-revision. Conclusion. Overall, 26 risk factors have been associated with an increased risk of re-revision following rTKA. However, various levels of methodological bias were found in the studies. Future studies should ensure valid comparisons by including patients with identical indications and using clear definitions for accurate assessments. Cite this article: Bone Jt Open 2024;5(8):644–651

Aims

Machine-learning (ML) prediction models in orthopaedic trauma hold great promise in assisting clinicians in various tasks, such as personalized risk stratification. However, an overview of current applications and critical appraisal to peer-reviewed guidelines is lacking. The objectives of this study are to 1) provide an overview of current ML prediction models in orthopaedic trauma; 2) evaluate the completeness of reporting following the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) statement; and 3) assess the risk of bias following the Prediction model Risk Of Bias Assessment Tool (PROBAST) tool.

Objectives. This review aims to summarize the outcomes used to describe effectiveness of treatments for paediatric wrist fractures within existing literature. Method. We searched the Cochrane Library, Scopus, and Ovid Medline for studies pertaining to paediatric wrist fractures. Three authors independently identified and reviewed eligible studies. This resulted in a list of outcome domains and outcomes measures used within clinical research. Outcomes were mapped onto domains defined by the COMET collaborative. Results. Our search terms identified 4,262 different papers. Screening of titles excluded 2,975, leaving 1,287 papers to be assessed for eligibility. Of this 1,287, 30 studies were included for full analysis. Overall, five outcome domains, 16 outcome measures, and 28 measurement instruments were identified as outcomes within these studies. 24 studies used at least one measurement pertaining to the physiological/clinical outcome domain. The technical, life impact, and adverse effect domains were recorded in 23, 20, and 11 of the studies respectively. Within each domain it was common for different measurement instruments to be used to assess each outcome measure. The most commonly reported outcome measures were range of movement, a broad array of “radiological measures” and pain intensity, which were used in 24, 23, and 12 of the 30 studies. Conclusion. This study highlights the heterogeneity in outcomes reported within clinical effectiveness studies of paediatric wrist fractures. We provided an overview of the types of outcomes reported in paediatric wrist fracture studies and identified a list of potentially relevant outcomes required for the development of a core outcome set

Aims. To analyze outcomes reported in studies of Ponseti correction of idiopathic clubfoot. Methods. A systematic review of the literature was performed to identify a list of outcomes and outcome tools reported in the literature. A total of 865 studies were screened following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and 124 trials were included in the analysis. Data extraction was completed by two researchers for each trial. Each outcome tool was assigned to one of the five core areas defined by the Outcome Measures Recommended for use in Randomized Clinical Trials (OMERACT). Bias assessment was not deemed necessary for the purpose of this paper. Results. In total, 20 isolated outcomes and 16 outcome tools were identified representing five OMERACT domains. Most outcome tools were appropriately designed for children of walking age but have not been embraced in the literature. The most commonly reported isolated outcomes are subjective and qualitative. The quantitative outcomes most commonly used are ankle range of motion (ROM), foot position in standing, and muscle function. Conclusions. There is a diverse range of outcomes reported in studies of Ponseti correction of clubfoot. Until outcomes can be reported unequivocally and consistently, research in this area will be limited. Completing the process of establishing and validating COS is the much-needed next step. Cite this article: Bone Joint Open 2020;1-8:457–464

Aims. To systematically review the predominant complication rates and changes to patient-reported outcome measures (PROMs) following osteochondral allograft (OCA) transplantation for shoulder instability. Methods. This systematic review, following PRISMA guidelines and registered in PROSPERO, involved a comprehensive literature search using PubMed, Embase, Web of Science, and Scopus. Key search terms included “allograft”, “shoulder”, “humerus”, and “glenoid”. The review encompassed 37 studies with 456 patients, focusing on primary outcomes like failure rates and secondary outcomes such as PROMs and functional test results. Results. A meta-analysis of primary outcomes across 17 studies revealed a dislocation rate of 5.1% and an increase in reoperation rates from 9.3% to 13.7% post-publication bias adjustment. There was also a noted rise in conversion to total shoulder arthroplasty and incidence of osteoarthritis/osteonecrosis over longer follow-up periods. Patient-reported outcomes and functional tests generally showed improvement, albeit with notable variability across studies. A concerning observation was the consistent presence of allograft resorption, with rates ranging from 33% to 80%. Comparative studies highlighted similar efficacy between distal tibial allografts and Latarjet procedures in most respects, with some differences in specific tests. Conclusion. OCA transplantation presents a promising treatment option for shoulder instability, effectively addressing both glenoid and humeral head defects with favourable patient-reported outcomes. These findings advocate for the inclusion of OCA transplantation in treatment protocols for shoulder instability, while also emphasizing the need for further high-quality, long-term research to better understand the procedure’s efficacy profile. Cite this article: Bone Jt Open 2024;5(7):570–580

Aims. Revision rates for ankle arthroplasties are higher than hip or knee arthroplasties. When a total ankle arthroplasty (TAA) fails, it can either undergo revision to another ankle replacement, revision of the TAA to ankle arthrodesis (fusion), or amputation. Currently there is a paucity of literature on the outcomes of these revisions. The aim of this meta-analysis is to assess the outcomes of revision TAA with respect to surgery type, functional outcomes, and reoperations. Methods. A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Medline, Embase, Cinahl, and Cochrane reviews were searched for relevant papers. Papers analyzing surgical treatment for failed ankle arthroplasties were included. All papers were reviewed by two authors. Overall, 34 papers met the inclusion criteria. A meta-analysis of proportions was performed. Results. Six papers analyzed all-cause reoperations of revision ankle arthroplasties, and 14 papers analyzed failures of conversion of a TAA to fusion. It was found that 26.9% (95% confidence interval (CI) 15.4% to 40.1%) of revision ankle arthroplasties required further surgical intervention and 13.0% (95% CI 4.9% to 23.4%) of conversion to fusions; 14.4% (95% CI 8.4% to 21.4%) of revision ankle arthroplasties failed and 8% (95% CI 4% to 13%) of conversion to fusions failed. Conclusion. Revision of primary TAA can be an effective procedure with improved functional outcomes, but has considerable risks of failure and reoperation, especially in those with periprosthetic joint infection. In those who undergo conversion of TAA to fusion, there are high rates of nonunion. Further comparative studies are required to compare both operative techniques. Cite this article: Bone Jt Open 2022;3(7):596–606

Aims. Return to sport following undergoing total (TKA) and unicompartmental knee arthroplasty (UKA) has been researched with meta-analyses and systematic reviews of varying quality. The aim of this study is to create an umbrella review to consolidate the data into consensus guidelines for returning to sports following TKA and UKA. Methods. Systematic reviews and meta-analyses written between 2010 and 2020 were systematically searched. Studies were independently screened by two reviewers and methodology quality was assessed. Variables for analysis included objective classification of which sports are safe to participate in postoperatively, time to return to sport, prognostic indicators of returning, and reasons patients do not. Results. A total of 410 articles were found, including 58 duplicates. Seven articles meeting inclusion criteria reported that 34% to 100% of patients who underwent TKA or UKA were able to return to sports at 13 weeks and 12 weeks respectively, with UKA patients more likely to do so. Prior experience with the sport was the most significant prognostic indicator for return. These patients were likely to participate in low-impact sports, particularly walking, cycling, golf, and swimming. Moderate-impact sport participation, such as doubles tennis and skiing, may be considered on a case-by-case basis considering the patient’s prior experience. There is insufficient long-term data on the risks to return to high-impact sport, such as decreased implant survivorship. Conclusion. There is a consensus that patients can return to low-impact sports following TKA or UKA. Return to moderate-impact sport was dependent on a case-by-case basis, with emphasis on the patient’s prior experience in the sport. Return to high-impact sports was not supported. Patients undergoing UKA return to sport one week sooner and with more success than TKA. Future studies are needed to assess long-term outcomes following return to high-impact sports to establish evidence-based recommendations. This review summarizes all available data for the most up-to-date and evidence-based guidelines for returning to sport following TKA and UKA to replace guidelines based on subjective physician survey data. Cite this article: Bone Jt Open 2022;3(3):245–251

Aims. Evidence exists of a consistent decline in the value and time that medical schools place upon their undergraduate orthopaedic placements. This limited exposure to trauma and orthopaedics (T&O) during medical school will be the only experience in the speciality for the majority of doctors. This review aims to provide an overview of undergraduate orthopaedic training in the UK. Methods. This review summarizes the relevant literature from the last 20 years in the UK. Articles were selected from database searches using MEDLINE, EMBASE, ERIC, Cochrane, and Web of Science. A total of 16 papers met the inclusion criteria. Results. The length of exposure to T&O is declining; the mean total placement duration of two to three weeks is significantly less than the four- to six-week minimum advised by most relevant sources. The main teaching methods described in the literature included didactic lectures, bedside teaching, and small group case-based discussions. Students preferred interactive, blended learning teaching styles over didactic methods. This improvement in satisfaction was reflected in improvements in student assessment scores. However, studies failed to assess competencies in clinical skills and examinations, which is consistent with the opinions of UK foundation year doctors, approximately 40% of whom report a “poor” understanding of orthopaedics. Furthermore, the majority of UK doctors are not exposed to orthopaedics at the postgraduate level, which only serves to amplify the disparity between junior and generalist knowledge, and the standards expected by senior colleagues and professional bodies. Conclusion. There is a deficit in undergraduate orthopaedic training within the UK which has only worsened in the last 20 years, leaving medical students and foundation doctors with a potentially significant lack of orthopaedic knowledge. Cite this article: Bone Jt Open 2022;3(7):549–556

Aims. To systematically review the efficacy of split tendon transfer surgery on gait-related outcomes for children and adolescents with cerebral palsy (CP) and spastic equinovarus foot deformity. Methods. Five databases (CENTRAL, CINAHL, PubMed, Embase, Web of Science) were systematically screened for studies investigating split tibialis anterior or split tibialis posterior tendon transfer for spastic equinovarus foot deformity, with gait-related outcomes (published pre-September 2022). Study quality and evidence were assessed using the Methodological Index for Non-Randomized Studies, the Risk of Bias In Non-Randomized Studies of Interventions, and the Grading of Recommendations Assessment, Development and Evaluation. Results. Overall, 17 studies (566 feet) were included: 13 studies used clinical grading criteria to report a postoperative ‘success’ of 87% (75% to 100%), 14 reported on orthotic use with 88% reduced postoperative use, and one study reported on ankle kinematics improvements. Ten studies reported post-surgical complications at a rate of 11/390 feet (2.8%), but 84 feet (14.8%) had recurrent varus (68 feet, 12%) or occurrence of valgus (16 feet, 2.8%). Only one study included a patient-reported outcome measure (pain). Conclusion. Split tendon transfers are an effective treatment for children and youth with CP and spastic equinovarus foot deformities. Clinical data presented can be used for future study designs; a more standardized functional and patient-focused approach to evaluating outcomes of surgical intervention of gait may be warranted. Cite this article: Bone Jt Open 2023;4(5):283–298

Aims. Recurrent dislocation is both a cause and consequence of glenoid bone loss, and the extent of the bony defect is an indicator guiding operative intervention. Literature suggests that loss greater than 25% requires glenoid reconstruction. Measuring bone loss is controversial; studies use different methods to determine this, with no clear evidence of reproducibility. A systematic review was performed to identify existing CT-based methods of quantifying glenoid bone loss and establish their reliability and reproducibility. Methods. A Preferred Reporting Items for Systematic reviews and Meta-Analyses-compliant systematic review of conventional and grey literature was performed. Results. A total of 25 studies were initially eligible. Following screening, nine papers were included for review. Main themes identified compared 2D and 3D imaging, as well as linear- compared with area-based techniques. Heterogenous data were acquired, and therefore no meta-analysis was performed. Conclusion. No ideal CT-based method is demonstrated in the current literature, however evidence suggests that surface area methods are more reproducible and lead to fewer over-estimations of bone loss, provided the views used are standardized. A prospective imaging trial is required to provide a more definitive answer to this research question. Cite this article: Bone Jt Open 2022;3(2):114–122

Aims. Posterior malleolar (PM) fractures are commonly associated with ankle fractures, pilon fractures, and to a lesser extent tibial shaft fractures. The tibialis posterior (TP) tendon entrapment is a rare complication associated with PM fractures. If undiagnosed, TP entrapment is associated with complications, ranging from reduced range of ankle movement to instability and pes planus deformities, which require further surgeries including radical treatments such as arthrodesis. Methods. The inclusion criteria applied in PubMed, Scopus, and Medline database searches were: all adult studies published between 2012 and 2022; and studies written in English. Outcome of TP entrapment in patients with ankle injuries was assessed by two reviewers independently. Results. Four retrospective studies and eight case reports were accepted in this systematic review. Collectively there were 489 Pilon fractures, 77 of which presented with TP entrapment (15.75%). There were 28 trimalleolar fractures, 12 of which presented with TP entrapment (42.86%). All the case report studies reported inability to reduce the fractures at initial presentation. The diagnosis of TP entrapment was made in the early period in two (25%) cases, and delayed diagnosis in six (75%) cases reported. Using modified Clavien-Dindo complication classification, 60 (67%) of the injuries reported grade IIIa complications and 29 (33%) grade IIIb complications. Conclusion. TP tendon was the commonest tendon injury associated with pilon fracture and, to a lesser extent, trimalleolar ankle fracture. Early identification using a clinical suspicion and CT imaging could lead to early management of TP entrapment in these injuries, which could lead to better patient outcomes and reduced morbidity. Cite this article: Bone Jt Open 2024;5(3):252–259

Aims. Preprint servers allow authors to publish full-text manuscripts or interim findings prior to undergoing peer review. Several preprint servers have extended their services to biological sciences, clinical research, and medicine. The purpose of this study was to systematically identify and analyze all articles related to Trauma & Orthopaedic (T&O) surgery published in five medical preprint servers, and to investigate the factors that influence the subsequent rate of publication in a peer-reviewed journal. Methods. All preprints covering T&O surgery were systematically searched in five medical preprint servers (medRxiv, OSF Preprints, Preprints.org, PeerJ, and Research Square) and subsequently identified after a minimum of 12 months by searching for the title, keywords, and corresponding author in Google Scholar, PubMed, Scopus, Embase, Cochrane, and the Web of Science. Subsequent publication of a work was defined as publication in a peer-reviewed indexed journal. The rate of publication and time to peer-reviewed publication were assessed. Differences in definitive publication rates of preprints according to geographical origin and level of evidence were analyzed. Results. The number of preprints increased from 2014 to 2020 (p < 0.001). A total of 38.6% of the identified preprints (n = 331) were published in a peer-reviewed indexed journal after a mean time of 8.7 months (SD 5.4 (1 to 27)). The highest proportion of missing subsequent publications was in the preprints originating from Africa, Asia/Middle East, and South America, or in those that covered clinical research with a lower level of evidence (p < 0.001). Conclusion. Preprints are being published in increasing numbers in T&O surgery. Depending on the geographical origin and level of evidence, almost two-thirds of preprints are not subsequently published in a peer-reviewed indexed journal after one year. This raises major concerns regarding the dissemination and persistence of potentially wrong scientific work that bypasses peer review, and the orthopaedic community should discuss appropriate preventive measures. Cite this article: Bone Jt Open 2022;3(7):582–588

Aims. Giant cell tumour of bone (GCTB) treatment changed since the introduction of denosumab from purely surgical towards a multidisciplinary approach, with recent concerns of higher recurrence rates after denosumab. We evaluated oncological, surgical, and functional outcomes for distal radius GCTB, with a critically appraised systematic literature review. Methods. We included 76 patients with distal radius GCTB in three sarcoma centres (1990 to 2019). Median follow-up was 8.8 years (2 to 23). Seven patients underwent curettage, 38 curettage with adjuvants, and 31 resection; 20 had denosumab. Results. Recurrence rate was 71% (5/7) after curettage, 32% (12/38) after curettage with adjuvants, and 6% (2/31) after resection. Median time to recurrence was 17 months (4 to 77). Recurrences were treated with curettage with adjuvants (11), resection (six), or curettage (two). Overall, 84% (38/45) was cured after one to thee intralesional procedures. Seven patients had 12 months neoadjuvant denosumab (5 to 15) and sixmonths adjuvant denosumab; two recurred (29%). Twelve patients had six months neoadjuvant denosumab (4 to 10); five recurred (42%). Two had pulmonary metastases (2.6%), both stable after denosumab. Complication rate was 18% (14/76, with 11 requiring surgery). At follow-up, median MusculoSkeletal Tumour Society score was 28 (18 to 30), median Short Form-36 Health Survey was 86 (41 to 95), and median Disability of Arm, Shoulder, and Hand was 7.8 (0 to 58). Conclusion. Distal radius GCTB treatment might deviate from general GCTB treatment because of complexity of wrist anatomy and function. Novel insights on surgical treatment are presented in this multicentre study and systematic review. Intralesional surgery resulted in high recurrence-rate for distal radius GCTB, also with additional denosumab. The large majority of patients however, were cured after repeated curettage. Cite this article: Bone Jt Open 2022;3(7):515–528

Aims. The aim of this study was to determine the effectiveness of home-based prehabilitation on pre- and postoperative outcomes in participants awaiting total knee (TKA) and hip arthroplasty (THA). Methods. A systematic review with meta-analysis of randomized controlled trials (RCTs) of prehabilitation interventions for TKA and THA. MEDLINE, CINAHL, ProQuest, PubMed, Cochrane Library, and Google Scholar databases were searched from inception to October 2022. Evidence was assessed by the PEDro scale and the Cochrane risk-of-bias (ROB2) tool. Results. A total of 22 RCTs (1,601 patients) were identified with good overall quality and low risk of bias. Prehabilitation significantly improved pain prior to TKA (mean difference (MD) -1.02: p = 0.001), with non-significant improvements for function before (MD -0.48; p = 0.06) and after TKA (MD -0.69; p = 0.25). Small preoperative improvements were observed for pain (MD -0.02; p = 0.87) and function (MD -0.18; p = 0.16) prior to THA, but no post THA effect was found for pain (MD 0.19; p = 0.44) and function (MD 0.14; p = 0.68). A trend favouring usual care for improving quality of life (QoL) prior to TKA (MD 0.61; p = 0.34), but no effect on QoL prior (MD 0.03; p = 0.87) or post THA (MD -0.05; p = 0.83) was found. Prehabilitation significantly reduced hospital length of stay (LOS) for TKA (MD -0.43 days; p < 0.001) but not for THA (MD, -0.24; p = 0.12). Compliance was only reported in 11 studies and was excellent with a mean value of 90.5% (SD 6.82). Conclusion. Prehabilitation interventions improve pain and function prior to TKA and THA and reduce hospital LOS, though it is unclear if these effects enhance outcomes postoperatively. Cite this article: Bone Jt Open 2023;4(5):315–328

Aims. This systematic review and meta-analysis was conducted to compare open reduction and internal fixation (ORIF) with primary arthrodesis (PA) in the treatment of Lisfranc injuries, regarding patient-reported outcome measures (PROMs), and risk of secondary surgery. The aim was to conclusively determine the best available treatment based on the most complete and recent evidence available. Methods. A systematic search was conducted in PubMed, Cochrane Controlled Register of Trials (CENTRAL), EMBASE, CINAHL, PEDro, and SPORTDiscus. Additionally, ongoing trial registers and reference lists of included articles were screened. Risk of bias (RoB) and level of evidence were assessed using the Cochrane risk of bias tools and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool. The random and fixed-effect models were used for the statistical analysis. Results. A total of 20 studies were selected for this review, of which 12 were comparative studies fit for meta-analysis, including three randomized controlled trials (RCTs). This resulted in a total analyzed population of 392 patients treated with ORIF and 249 patients treated with PA. The mean differences between the two groups in American Orthopedic Foot and Ankle Society (AOFAS), VAS, and SF-36 scores were -7.41 (95% confidence interval (CI) -13.31 to -1.51), 0.77 (95% CI -0.85 to 2.39), and -1.20 (95% CI -3.86 to 1.46), respectively. Conclusion. This is the first study to find a statistically significant difference in PROMs, as measured by the AOFAS score, in favour of PA for the treatment of Lisfranc injuries. However, this difference may not be clinically relevant, and therefore drawing a definitive conclusion requires confirmation by a large prospective high-quality RCT. Such a study should also assess cost-effectiveness, as cost considerations might be decisive in decision-making. Level of Evidence: I. Cite this article: Bone Jt Open 2021;2(10):842–849

Aims. It is important to understand the rate of complications associated with the increasing burden of revision shoulder arthroplasty. Currently, this has not been well quantified. This review aims to address that deficiency with a focus on complication and reoperation rates, shoulder outcome scores, and comparison of anatomical and reverse prostheses when used in revision surgery. Methods. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) systematic review was performed to identify clinical data for patients undergoing revision shoulder arthroplasty. Data were extracted from the literature and pooled for analysis. Complication and reoperation rates were analyzed using a meta-analysis of proportion, and continuous variables underwent comparative subgroup analysis. Results. A total of 112 studies (5,379 shoulders) were eligible for inclusion, although complete clinical data was not ubiquitous. Indications for revision included component loosening 20% (601/3,041), instability 19% (577/3,041), rotator cuff failure 17% (528/3,041), and infection 16% (490/3,041). Intraoperative complication and postoperative complication and reoperation rates were 8% (230/2,915), 22% (825/3,843), and 13% (584/3,843) respectively. Intraoperative and postoperative complications included iatrogenic humeral fractures (91/230, 40%) and instability (215/825, 26%). Revision to reverse total shoulder arthroplasty (TSA), rather than revision to anatomical TSA from any index prosthesis, resulted in lower complication rates and superior Constant scores, although there was no difference in American Shoulder and Elbow Surgeons scores. Conclusion. Satisfactory improvement in patient-reported outcome measures are reported following revision shoulder arthroplasty; however, revision surgery is associated with high complication rates and better outcomes may be evident following revision to reverse TSA. Cite this article: Bone Jt Open 2021;2(8):618–630

Background. Due to the overwhelming demand for trauma services, resulting from increasing emergency department attendances over the past decade, virtual fracture clinics (VFCs) have become the fashion to keep up with the demand and help comply with the BOA Standards for Trauma and Orthopaedics (BOAST) guidelines. In this article, we perform a systematic review asking, “How useful are VFCs?”, and what injuries and conditions can be treated safely and effectively, to help decrease patient face to face consultations. Our primary outcomes were patient satisfaction, clinical efficiency and cost analysis, and clinical outcomes. Methods. We performed a systematic literature search of all papers pertaining to VFCs, using the search engines PubMed, MEDLINE, and the Cochrane Database, according to the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) checklist. Searches were carried out and screened by two authors, with final study eligibility confirmed by the senior author. Results. In total, 21 records were relevant to our research question. Six orthopaedic injuries were identified as suitable for VFC review, with a further four discussed in detail. A reduction of face to face appointments of up to 50% was reported with greater compliance to BOAST guidelines (46.4%) and cost saving (up to £212,000). Conclusions. This systematic review demonstrates that the VFC model can help deliver a safe, more cost-effective, and more efficient arm of the trauma service to patients. Cite this article: Bone Joint Open 2020;1-11:683–690

Aims. Metal allergy in knee arthroplasty patients is a controversial topic. We aimed to conduct a scoping review to clarify the management of metal allergy in primary and revision total knee arthroplasty (TKA). Methods. Studies were identified by searching electronic databases: Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and Embase, from their inception to November 2020, for studies evaluating TKA patients with metal hypersensitivity/allergy. All studies reporting on diagnosing or managing metal hypersensitivity in TKA were included. Data were extracted and summarized based on study design, study population, interventions and outcomes. A practical guide is then formulated based on the available evidence. Results. We included 38 heterogeneous studies (two randomized controlled trials, six comparative studies, 19 case series, and 11 case reports). The evidence indicates that metal hypersensitivity is a rare complication with some histopathological features leading to pain and dissatisfaction with no reliable screening tests preoperatively. Hypoallergenic implants are viable alternatives for patients with self-reported/confirmed metal hypersensitivity if declared preoperatively; however, concerns remain over their long-term outcomes with ceramic implants outperforming titanium nitride-coated implants and informed consent is paramount. For patients presenting with painful TKA, metal hypersensitivity is a diagnosis of exclusion where patch skin testing, lymphocyte transformation test, and synovial biopsies are useful adjuncts before revision surgery is undertaken to hypoallergenic implants with shared decision-making and informed consent. Conclusion. Using the limited available evidence in the literature, we provide a practical approach to metal hypersensitivity in TKA patients. Future national/registry-based studies are needed to identify the scale of metal hypersensitivity, agreed diagnostic criteria, and management strategies. Cite this article: Bone Jt Open 2021;2(10):785–795

Aims. The aim of this meta-analysis is to assess the association between exchange of modular parts in debridement, antibiotics, and implant retention (DAIR) procedure and outcomes for hip and knee periprosthetic joint infection (PJI). Methods. We conducted a systematic search on PubMed, Embase, Web of Science, and Cochrane library from inception until May 2021. Random effects meta-analyses and meta-regression was used to estimate, on a study level, the success rate of DAIR related to component exchange. Risk of bias was appraised using the (AQUILA) checklist. Results. We included 65 studies comprising 6,630 patients. The pooled overall success after DAIR for PJI was 67% (95% confidence interval (CI) 63% to 70%). This was 70% (95% CI 65% to 75%) for DAIR for hip PJI and 63% (95% CI 58% to 69%) for knee PJI. In studies before 2004 (n = 27), our meta-regression analysis showed a 3.5% increase in success rates for each 10% increase in component exchange in DAIR for hip PJI and a 3.1% increase for each 10% increase in component exchange for knee PJI. When restricted to studies after 2004 (n = 37), this association changed: for DAIR for hip PJI a decrease in successful outcome by 0.5% for each 10% increase in component exchange and for DAIR for knee PJI this was a 0.01% increase in successful outcome for each 10% increase in component exchange. Conclusion. This systematic review and meta-regression found no benefit of modular component exchange on reduction of PJI failure. This limited effect should be weighed against the risks for the patient and cost on a case-by-case basis. The association between exchange of modular components and outcome changed before and after 2004. This suggests the effect seen after 2004 may reflect a more rigorous, evidence-based, approach to the infected implant compared to the years before. Level of Evidence: Level III. Cite this article: Bone Jt Open 2021;2(10):806–812

Aims

Robotic-assisted unicompartmental knee arthroplasty (R-UKA) has been proposed as an approach to improve the results of the conventional manual UKA (C-UKA). The aim of this meta-analysis was to analyze the studies comparing R-UKA and C-UKA in terms of clinical outcomes, radiological results, operating time, complications, and revisions.