Andrew Metcalfe

The robotic arm-assisted versus conventional total knee arthroplasty (RACER-Knee) trial

Is surgery for early hip or knee osteoarthritis clinically effective and cost-effective? Osteoarthritis is the most common joint disease worldwide costing between 1% and 2.5% of gross domestic product in developed countries. Once a hip or knee develops end-stage disease, arthroplasty surgery is highly successful in most patients. Treatment options are limited for early disease, and patients may fall into a 'treatment gap', despite having severe symptoms. Many surgical procedures are used to treat early osteoarthritis of the hip and knee, but the clinical and cost-effectiveness of these techniques remains unclear. To investigate the role of surgery in the management of early hip or knee osteoarthritis? Use systematic review and evidence synthesis to determine the clinical effectiveness of current surgical interventions for early hip and knee osteoarthritis. Estimate the cost-effectiveness of these procedures using decision model analytic modelling. Create clinical treatment guidance and identify areas where new clinical research is required. The programme of work consisted of systematic review, evidence synthesis and health economic modelling for surgical treatments used for early hip and knee osteoarthritis. We divided treatments into four groups: (1) non-regenerative procedures, (2) regenerative procedures, (3) load-modifying procedures and (4) arthroplasty procedures. They were compared with non-surgical treatment following National Institute for Health and Care Excellence guidance. We used outcome measures that satisfied the Outcome Measures in Rheumatoid Arthritis Clinical Trials and Osteoarthritis Research Society International core outcome set for hip and knee osteoarthritis. Decision-analytic models were developed to assess the cost-effectiveness of treatment alternatives expressed as cost per quality-adjusted life-year gained. The systematic review identified 61,098 studies, and our evidence synthesis identified a number of surgical techniques that have been used to treat early hip and knee osteoarthritis. However, we found very little meaningful evidence of the clinical efficacy for the majority of the surgical procedures. We only found seven randomised controlled trials and three non-randomised studies that compared a surgical technique to non-operative treatment. There were two surgical treatments that had limited but supportive evidence. Femoro-acetabular impingement is an early stage of hip osteoarthritis, and there is some evidence that arthroscopic chondroplasty provides patients with clinical relief of symptoms, above that seen with non-operative measures. In the knee, weaker evidence suggests arthroscopic debridement of osteoarthritic articular cartilage fragments may be of benefit, above non-operative measures. Health economic analysis suggests that both procedures may be cost-effective, but the evidence is again of low quality. The original updated searches completed in January 2021, with a further search for randomised controlled studies completed in January 2025. There is a significant gap in the evidence base supporting surgical interventions in early hip and knee osteoarthritis. Limited evidence suggests that arthroscopic chondroplasty procedures may be effective in treating hip femoro-acetabular impingement and early knee osteoarthritis. A small number of randomised studies are in progress, but these studies do not encompass all procedures that are in use. The key recommendation for future work is that more high-quality comparative studies are required to establish if the surgical interventions that are currently used are effective. This study is registered as PROSPERO CRD42019156444. This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127398) and is published in full in Health Technology Assessment; Vol. 30, No. 56. See the NIHR Funding and Awards website for further award information.

Introduction: People with body mass index (BMI) ≥35 kg/m ² have an approximately 19-fold increased risk of undergoing total knee replacement (TKR); however, many UK integrated care boards (37%) have restrictive policies which limit access to TKR for people based on BMI. Therefore, access to both surgical and non-surgical treatments varies widely, exacerbating existing health inequalities. It remains unclear how decisions about offering TKR are made in people with severe knee osteoarthritis, which weight-loss interventions are provided in practice and how different management pathways relate to patient outcomes among individuals with high BMI. Methods and analysis: This study will recruit 400 participants with severe Kellgren-Lawrence grade four knee osteoarthritis from eight secondary care centres in England. All participants, irrespective of BMI, will provide baseline clinical data and patient-reported outcome measures (PROMs), enabling characterisation of baseline associations between BMI, knee function and body image. A prespecified subgroup of participants with BMI ≥35 kg/m ² (minimum n=105) will undergo longitudinal follow-up at 6 months, 12 months and 24 months, including repeat BMI measurement, PROMs and detailed data on access to surgical and non-surgical interventions, including weight-loss strategies and TKR. For those with BMI ≥35 kg/m ² , statistical modelling will be used to explore associations between baseline factors and longitudinal outcomes including Oxford Knee Score and weight change at 12 months (n≥105). Structural equation modelling will be used to quantify associations between BMI and knee pain/function mediated by psychosocial factors using data from all participants (n=400). A nested qualitative study of surgeons and patients will explore obstacles and preferences in the management of severe knee osteoarthritis. Ethics and dissemination: The study received ethical approval from the West of Scotland REC 5 (Ref: 24/WS/0146) on 10 October 2024. Results will be disseminated through peer-reviewed publications. Trial registration number: ISRCTN42984928 .

Background: Patients with symptoms of pain and restricted function related to knee osteoarthritis are typically offered a knee replacement. However, a proportion remain dissatisfied with their outcomes, and the failure risk is disproportionately higher in the young. Knee joint distraction may be an intervention to postpone the time to knee replacement in this patient population. Objective and main outcome measure: The primary objective of the Knee Arthroplasty versus Joint Distraction Study for Osteoarthritis (KARDS) was to evaluate the effectiveness of knee joint distraction compared to knee replacement based on patient-reported pain 12 months post surgery using the Knee Injury and Osteoarthritis Outcomes Score pain score as the primary outcome. Design and methods: KARDS was an open-label, two-arm individually randomised controlled non-inferiority trial with an embedded 12-month internal pilot phase and process evaluation to evaluate recruitment feasibility. A hybrid expertise design was used to account for surgeon expertise and potential lack of individual equipoise. The trial was closed to recruitment early following cessation of elective orthopaedic surgery secondary to COVID-19 pandemic. Descriptive statistics are reported. Setting: United Kingdom National Health Service Trusts. Participants: Adult patients aged < 65 years with symptoms severe enough to warrant knee replacement, in the opinion of the treating clinician. Interventions: Participants were randomised to receive either knee joint distraction (static distraction of 5 mm, using external fixator for 6 weeks) or knee replacement. Results: Twenty-four participants were randomised from a single centre between March 2021 and October 2022 with minimum 3-month safety follow-up post surgery. Eleven participants were randomised to knee joint distraction and 13 to knee replacement. Seventeen patients were male (71%), median age 60 (47–65) years. One patient withdrew due to being medically unfit for surgery and two received a different treatment than which they were randomised (one crossover from each arm). The median Knee Injury and Osteoarthritis Outcomes Score pain score in the knee joint distraction group improved from 38.9 (22–50) at baseline to 55.6 (0–100) at 12 months, corresponding scores in the knee replacement improved from 30.6 (6–36) to 75.0 (50–100). Adverse events were more common with knee joint distraction, pin site infection being the commonest complications ( n = 4, 58%). As part of process evaluation, we conducted semistructured qualitative interviews with staff in secondary care and with study participants. Data were analysed using thematic content analysis. One overarching theme emerged: ‘An unexpected journey’, which encapsulates staff and participants’ experiences. Conclusion: Reduced research capacity and the suspension of elective surgery following the COVID-19 pandemic caused significant recruitment barriers. Despite early termination, KARDS demonstrated that patients were willing to be recruited to a trial investigating a novel treatment for knee osteoarthritis and the trial was feasible and implementable. The limited results indicated that the technique is safe with no safety concerns. Clinical and cost-effectiveness of knee joint distraction remains uncertain. The embedded KARDS process evaluation has provided helpful insights. Limitations: Reduced research capacity at sites and suspension of elective surgery services within the United Kingdom following COVID-19 caused significant recruitment barriers to KARDS. All the recruited patients in both arms of the study were White. Future work: As a commissioned piece of research with delivery significantly impacted by the National Health Service environment post-COVID and the impact on National Health Service surgical services, the research question remains highly relevant. Any future research in this field can be helped by the pilot data published here along with the lessons learnt. Funding: This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number 17/122/06.

Background: Open fractures are common and severe injuries that are associated with poor functional outcomes and quality of life, and high societal costs. Several classifications systems have been developed to characterize these injuries, predict prognosis and plan treatment. We aimed to assess the agreement between open fracture classification and patient-reported function, fracture-related infection, and amputation. Methods: In this prospective cohort study, we enrolled adults with open tibia fractures in 6 hospitals across Malawi. Radiographs and clinical photographs were classified according to the Gustilo-Anderson, Orthopaedic Trauma Society (OTS), Muller and Tscherne classification by an orthopaedic surgeon. Participants' function (using the Short Musculoskeletal Assessment Score), and risk of fracture-related infection and amputation were assessed by face-to-face interviews at 6 weeks, 3 months, 6 months, and 1 year postinjury. The Kendall rank correlation coefficient with 95% bootstrapped confidence intervals investigated correlation between fracture classifications and patient outcomes. Results: Two hundred eighty-seven participants were recruited with 252 of 287 photographs (88%) and 274 of 287 radiographs (95%) available for review. The Kendall correlation with function score 1 year after injury was 0.34 for OTS classification, 0.18 for Gustilo, 0.17 for Tscherne, and -0.02 for Muller. For correlation with fracture-related-infection at 1 year, this was 0.34 for the Orthopaedic Trauma Society, 0.31 for Gustilo, 0.24 for Tscherne, −0.02 for Muller. For amputation, correlation was 0.39 for OTS, 0.24 for Gustilo, 0.24 for Tscherne, and 0.12 for Muller. Discussions: Most open fracture classification systems had negligible or weak correlation with subsequent patient function, fracture-related infection, or amputation in Malawi. Treatment factors and other confounders may have a greater influence on outcomes, but classification systems must still account for this variability to remain useful. More research in low or middle income countries needs to be conducted to develop appropriate and relevant open fracture classifications to improve and standardize the management of open fractures. Level of Evidence: Level II. See Instructions for Authors for a complete description of levels of evidence.

Background: Computer navigation and patient-specific instrumentation in unicompartmental knee replacement (UKR) improve the precision of implant positioning, but there is limited information regarding their impact on implant survival and patient-reported outcomes. We aimed to compare postoperative implant survival, Oxford Knee Score (OKS) values, health-related quality of life (measured using the EuroQol-5 Dimension 3-level version [EQ-5D-3L]), and intraoperative complications between UKRs performed using computer navigation or patient-specific instrumentation versus conventional instrumentation. Methods: Using National Joint Registry data, an observational study of patients who underwent primary UKR for osteoarthritis between 2003 and 2020 was performed. The primary analyses focused on all-cause revision, and the secondary analyses focused on differences in the OKS and EQ-5D-3L at 6 to 12 months postoperatively. To account for several covariates, weights based on propensity scores were generated. Cox proportional hazards models and generalized linear models were used to assess for differences in revision risk, and OKS and EQ-5D-3L change scores, respectively, between patient groups. Sensitivity analyses accounting for body mass index were performed. Effective sample sizes (ESSs) were computed, representing the statistical power comparable with that of an unweighted sample. Results: Compared with conventional instrumentation, the hazard ratio (HR) for all-cause revision was 1.126 (95% confidence interval [CI], 0.909 to 1.395; p = 0.277; ESS, 4,273) with computer navigation and 0.805 (95% CI, 0.442 to 1.467; p = 0.478; ESS, 1,199) with patient-specific instrumentation. No difference was found in the change in OKS between the groups (−1.287; 95% CI, −2.851 to 0.278; p = 0.107; ESS, 470), although improvement in the EQ-5D-3L scores was relatively lower for computer-navigated UKR compared with conventional instrumentation (−0.049, 95% CI, −0.093 to −0.005; p = 0.028; ESS, 455). However, sensitivity analyses demonstrated that computer navigation was associated with an increased risk of all-cause revision (HR, 1.446; 95% CI, 1.102 to 1.898; p = 0.008; ESS, 3,011) and relatively smaller improvements in the OKS (−2.845; 95% CI, −5.006 to −0.684; p = 0.010; ESS, 272) and EQ-5D-3L scores (−0.087; 95% CI, −0.145 to −0.030; p = 0.003; ESS, 286). There were no differences in intraoperative complications (p = 0.073). Conclusions: This study found no clinically meaningful differences in patient-reported outcomes following computer-navigated UKR. Although likely underpowered, the primary analyses showed no difference in implant survival. While a sensitivity analysis suggested that computer navigation could worsen implant survival, this analysis had a smaller sample size. These findings highlight potential signals that warrant further investigation. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Purpose: Synthetic augmentation (SA) in anterior cruciate ligament reconstruction (ACLR) aims to enhance graft durability, but its benefits remain unclear. To evaluate whether SA in ACLR improves return‐to‐sport (RTS) rates, reduces graft failure, enhances patient‐reported outcomes (PROs) and varies in effectiveness across materials and techniques. Methods: A systematic search of five databases was conducted until February 2025. Comparative studies were pooled using Hedges' random‐effects meta‐analysis with subgroup analysis based on materials and publication year. Non‐comparative studies were analysed narratively. Risk of bias was assessed using the Risk of Bias in Non‐randomised Studies of Interventions and the Cochrane risk‐of‐bias tools for randomised studies. Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of evidence. Results: Forty‐seven studies were included ( n = 4289): 7 randomised and 40 non‐randomised studies (21 comparative; 19 non‐comparative). SA systems included InternalBrace (FiberTape, 16 studies), Ligament Augmentation and Reconstruction System (polyester, 5), Ligament Augmentation Device (polyethylene, 18) and other materials (8). GRADE assessment showed moderate‐certainty evidence for improved mid‐term RTS rate from eight studies (odds ratio [OR]: 1.58; 95% confidence interval (CI): 1.12–2.22; N = 716; I ² = 0%; p = 0.01). Internal brace showed a reduction in re‐rupture rates in the long‐term (OR: 0.17, 95% CI: 0.04–0.64; N = 218; I ² = 0%; p = 0.01); however, pooled analysis of all techniques showed no statistically significant difference. Contemporary studies showed a better return to sport rates with SA. PROs showed no clinically meaningful differences. Non‐comparative studies showed low graft failure rates (56.7% for other SA) and satisfactory PROs. Conclusions: SA, particularly InternalBrace, may improve RTS rates and reduce re‐rupture risk, though PROs remain inconclusive. Findings are limited by a moderate‐to‐serious risk of bias, emphasising the need for high‐quality research. Level of Evidence: Level III.

Background: The best management of irreparable rotator cuff tears remains uncertain, with multiple new techniques introduced over the past 2 decades. Two options for treatment are arthroscopic debridement and biceps tenotomy, or the subacromial balloon spacer. Early trial results favored the former option, but the 2-year results have not yet been reported. Purpose: To report the 2-year follow-up outcomes of the START:REACTS trial, investigating the use of a subacromial balloon spacer for irreparable rotator cuff tears of the shoulder. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Eligible participants had an irreparable rotator cuff tear, intrusive symptoms requiring surgery, and previous unsuccessful nonoperative care. Participants were randomized 1:1 to debridement of the subacromial space with biceps tenotomy (debridement only) or the same procedure with the addition of the subacromial balloon spacer (debridement with device). The 12-month primary outcome was previously reported; this article presents the 24-month results. Linear regression models were used to analyze the 24-month data. Results: Recruitment stopped early at the preplanned interim analysis, with 117 participants in the trial. A total of 99 (85%) participants out of 117 were followed up to 24 months. At 24 months, a significant difference in the Oxford Shoulder Score was not found (95% CI, –7.9 to 0.4; P = .08). The Western Ontario Rotator Cuff score (mean difference, –10.1; 95% CI, –19.5 to −0.8; P = .04) and Patient Global Impression of Change (odds ratio, 0.4; 95% CI, 0.2 to 0.8; P = .015) were found to significantly favor debridement only. The EQ-5D-5L (mean difference, −0.009; 95% CI, −0.107 to 0.088; P = .85) and satisfaction scores (odds ratio, 0.6; 95% CI, 0.3 to −1.2; P = .14) were not significantly different. Complications were evenly matched between groups over 24 months. Conclusion: Participants continued to show better results in the debridement-only group compared with the group who had debridement with the InSpace balloon. Therefore, we do not recommend the subacromial balloon spacer for the treatment of irreparable rotator cuff tears.