Abstract. Introduction. There is a need to develop approaches to reduce chronic pain after total knee replacement. There is an established link between disturbed sleep and pain. We tested the feasibility of a trial evaluating the clinical and cost-effectiveness of a pre-operative sleep assessment and complex intervention package for improving long-term pain after TKR. Methodology. REST was a feasibility multi-centre randomised controlled trial with embedded qualitative study and health economics. Participants completed baseline measures and were randomised to usual care or the intervention, a tailored sleep assessment and behavioural intervention package delivered by an extended scope practitioner three months pre-operatively with a follow-up call up at four-weeks. Patient reported outcomes were assessed at baseline, one-week pre-surgery, and 3-months post-surgery. Results. 57 patients were randomised and 20 had surgery within the study timelines. All patients allocated the intervention attended an appointment and most engaged with treatment. The intervention group reported improvements in sleep (Sleep Conditions Indicator) and neuropathic pain (painDETECT) scores. Participants found the sleep treatments and study processes to be acceptable. The mean cost of the intervention was estimated at £134.45 per patient. Conclusion. The feasibility study has shown that patient recruitment is feasible, engagement with and adherence to the intervention is high, and the intervention is acceptable to patients and clinicians. Preliminary findings show that the intervention group had improved sleep quality and had reduced levels of pre-operative neuropathic pain. This study has demonstrated that a full RCT is feasible and identified areas for improvement to optimize the trial design

Abstract. INTRODUCTION. Geniculate nerve blocks (GNB) and ablation (GNA) are increasing in popularity as strategies for the management of knee pain in patients unsuitable for surgical intervention. Typically these simple blocks have been performed by specialists in pain medicine. We present the results of a GNB clinic run by a surgical care practitioner (SCP). METHODOLOGY. An SCP clinic was created where ultrasound-guided GNBs comprising local anaesthetic and steroid were administered. Patients considered unsuitable for surgery were referred with knee pain by orthopaedic knee surgeons and specialist physiotherapists. A VAS pain score and an Oxford Knee Score (OKS) were completed prior to and immediately following blockade. Serial VAS diaries were completed. Further OKS were requested at 6 weeks and 6 months. Patients could request GNA at any point during follow-up and their follow-up ceased at this stage. RESULTS. 50 patients were identified between December 2020 and 2021. Patients are followed up until 6 months post-block or until referral for GNA. Pre-blockade mean OKS was 13.4, mean VAS 8.6, post procedure mean VAS 2.7. Six-week mean OKS was 20.9 in those not referred for ablation, mean improvement of 7.3. Of the cohort of 50, 25 have progressed to ablation. CONCLUSION. GNB is a simple procedure which can provide both lasting symptomatic relief and prognostic information in the treatment of patients with knee pain not amenable to surgical intervention, a growing subset of patients. This SCP-led clinic increases capacity for the provision of GNBs, helping to identify patients suitable for GNA

Aims. To date, no study has demonstrated an improvement in postoperative outcomes following elective joint arthroplasty with a focus on nutritional intervention for patients with preoperative hypoalbuminaemia. In this prospective study, we evaluated differences in the hospital length of stay (LOS), rate of re-admission, and total patient charges for a malnourished patient study population who received a specific nutrition protocol before surgery. Patients and Methods. An analytical report was extracted from the electronic medical record (EMR; Epic, Verona, Wisconsin) of a five-hospital network joint arthroplasty patient data set between 2014 and 2017. A total of 4733 patients underwent joint arthroplasty and had preoperative measurement of albumin levels: 2220 at four hospitals and 2513 at the study hospital. Albumin ≤ 3.4 g/l, designated as malnutrition, was found in 543 patients (11.5%). A nutritional intervention programme focusing on a high-protein, anti-inflammatory diet was initiated in January 2017 at one study hospital. Hospital LOS, re-admission rate, and 90-day charges were compared for differential change between patients in study and control hospitals for all elective hip and knee arthroplasty patients, and for malnourished patients over time as the nutrition intervention was implemented. Results. Malnourished patients with nutritional intervention at the study hospital had shorter hospital LOS beginning in 2017 than malnourished patients at control hospitals during the same period (p = 0.04). Similarly, this cohort had significantly lower primary hospitalization charges, charges associated with hospital re-admissions, and 90-day total charges (p < 0.001). Inclusion of covariant potential confounders (age, anaemia, diabetes, and obesity) did not alter the conclusions of the primary statistical analysis. Conclusion. Joint arthroplasty outcomes were positively affected in study patients with low albumin when a high-protein, anti-inflammatory diet was encouraged. Elective surgery was neither cancelled nor delayed with a malnutrition designation. While the entire network population experienced improved postoperative outcomes, malnourished control patients did not experience this improvement. This study demonstrated that education on malnutrition can benefit patients. Cite this article: Bone Joint J 2019;101-B(7 Supple C):17–21

Abstract

Introduction. Overwhelming evidence has established obesity as a risk factor for osteoarthritis (OA) of the knee. Randomized clinical trials such as the Look AHEAD study have shown long term successful intentional weight loss with an intensive lifestyle intervention (ILI) in overweight and obese type 2 diabetics. Weight loss can also decrease knee pain in persons who have OA, but it is unknown if intentional weight loss can reduce the risk of TKR. To answer this question, data from the Look AHEAD study were examined to determine if intentional weight loss could reduce the risk of TKR. Methods. Look AHEAD is a multicenter, randomized trial which began in August 2001 and follow-up continued for a median of 11.3 years at 16 academic centers. 5145 persons aged 45–76 with diabetes were randomized to either an ILI with reduced calorie consumption and increased physical activity designed or to diabetes support and education intervention (DSE). TKR events were ascertained every 6 months. Retrospective data of reported knee pain was assessed using the WOMAC knee pain questionnaire. Participants with partial TKR or revisions were excluded. Cox proportional hazard models were used to relate baseline BMI category (obese, Class I, Class II, or Class III obesity), baseline knee pain, and treatment group with TKR. Weight change category (lost<=5%, stable, gained>=2%) from baseline to year 1 follow-up by treatment assignment was also examined as a predictor of TKR after excluding TKR occurring prior to year 1. Results. Out of the randomized participants, 2171 reported knee pain (43%) at the baseline visit (p=0.81). WOMAC knee pain score did not differ by random assignment (ILI:3.6±2.9, DSE:3.9±3.0, p=0.08). During follow up there were 631 TKRs reported by participants. TKR was more common in heavier (p<0.001), and older (p<0.001) participants and did not differ by randomization. Heterogeneity of treatment effect was observed with baseline knee pain (interaction p = 0.02), therefore analyses were stratified by presence or absence of knee pain at baseline. In persons without knee pain at baseline, there was a 29% reduced rate of TKR in the ILI group compared to the DSE group (HR[95%CI] 0.71[0.52,0.96]; Figure 1A). Whereas in persons with knee pain at baseline, there was a trend for the ILI to have an increased rate of TKR compared to DSE (1.11[0.92, 1.33]; Figure 1B). In both sets of analyses, obese participants had significantly higher hazard of TKR than overweight participants (No pain: Class I 1.78[1.04,3.05], Class II 2.27 [1.31,3.94], Class III 2.94[1.67,5.18]; With pain: Class I 1.70[1.12,2.59], Class II 2.42 [1.60,3.65], Class III 2.80[1.85,4.23]). When TKR incidence was examined by weight change at year 1 there was no difference in weight change category between randomization groups in persons with knee pain (interaction p=0.20) or without baseline knee pain (interaction p=0.87) (Figure 1C and D) or for the overall effect of year 1 weight loss category in either stratum (with knee pain p=0.26, without knee pain p=0.48). However, in persons without knee pain at baseline, ILI had a marginal reduction in hazard of TKR compared to DSE (0.71[0.49, 1.05]) but not in the group with baseline knee pain. Conclusions. In persons with no knee pain at baseline and who were overweight or had Class I or II obesity, ILI seemed to reduce the risk of TKR compared to DSE. In contrast, persons with knee pain who gained weight at 1 year and were randomized to ILI had the highest risk of TKR. This suggests that weight loss to prevent TKR may be more effective prior to the development of significant knee pain. After the onset of knee pain however, low impact or non-weight bearing activity should be considered to avoid worsening knee symptoms. For any figures or tables, please contact authors directly

Abstract. Introduction. Frailty is associated with poorer outcomes after joint replacement. Targeting frailty pre-operatively via protein supplementation and exercise has the potential to improve outcomes after joint replacement. Before conducting a randomised controlled trial (RCT), a feasibility study is necessary to address key uncertainties and explore how to optimise trial design. Methodology. Joint PREP is a feasibility study for a multicentre, two-arm, parallel group, pragmatic, RCT to evaluate the clinical and cost-effectiveness of prehabilitation for frail patients undergoing total hip or knee replacement. Sixty people who are ≥65 years of age, frail and scheduled to undergo total hip or knee replacement at 2–3 NHS hospitals will be recruited and randomly allocated on a 1:1 ratio to the intervention or usual care group. The intervention group will be given a daily protein supplement and will be asked to follow a home-based, tailored daily exercise programme for 12 weeks before their operation, supported by fortnightly telephone calls from a physiotherapist. Embedded qualitative research with patients will explore their experiences of participating, reasons for non-participation and/or reasons for withdrawal or treatment discontinuation. Results. Outcomes to be assessed include eligibility, recruitment and retention rates; intervention adherence; acceptability of the trial and intervention; and data completion. Data collection is ongoing. Discussion. This study will generate important data regarding the feasibility of a RCT to evaluate a prehabilitation intervention for frail patients undergoing joint replacement. A future RCT will contribute to the evidence on interventions to optimise the benefit that frail patients gain from joint replacement

Abstract. Design. A pragmatic, multicentre, parallel-group, randomised controlled trial to determine whether the intervention is superior to comparator. Setting. 20 NHS Hospitals. Population. NHS patients <60 years with moderate-severe symptomatic knee OA localised to the medial compartment in whom surgical intervention is indicated. Intervention. Surgery with medial opening wedge high tibial osteotomy (HTO) followed by standard postoperative rehabilitation based on local pathways. Comparator. Tailored non-surgical intervention delivered within an NHS physiotherapy department delivered over 6-contact sessions within a period of 4 months. Outcomes. Primary outcome - 24-month Knee Injury and Osteoarthritis Outcome Score (KOOS); Secondary outcomes - OKS, FJS-12, EQ-5D-3L, Pittsburgh Sleep Problem Scale, Return to Work, secondary surgical interventions and complications at 12 and 24 months following randomisation. Health economic evaluation - 24-month within trial analysis, and a decision analytic simulation model to account for the impacts of future knee replacements (and associated revisions), and their timing relative to retirement and employment potential. Process evaluation – to explore trial eligibility, recruitment and retention rates, acceptability of intervention implementation and patient experience of taking part/contextual factors that influence this. Follow up. 12 months and 24 months post-randomisation. Sample size. 224 patients; (90% power, 2-sided p=0.05, equivalent to a sample size of 97 per group). Allowing for 15% loss to follow up, 112 patients will be recruited to each arm of the trial. Project timelines. Start date 1 August 2022, total project duration 60 months including a 9-month, 5-site internal pilot, with a recruitment rate of 0.7 patients/site/month

Aims. This study investigated the effects of transcatheter arterial embolization (TAE) on pain, function, and quality of life in people with early-stage symptomatic knee osteoarthritis (OA) compared to a sham procedure. Methods. A total of 59 participants with symptomatic Kellgren-Lawrence grade 2 knee OA were randomly allocated to TAE or a sham procedure. The intervention group underwent TAE of one or more genicular arteries. The control group received a blinded sham procedure. The primary outcome was knee pain at 12 months according to the Knee injury and Osteoarthritis Outcome Score (KOOS) pain scale. Secondary outcomes included self-reported function and quality of life (KOOS, EuroQol five-dimension five-level questionnaire (EQ-5D-5L)), self-reported Global Change, six-minute walk test, 30-second chair stand test, and adverse events. Subgroup analyses compared participants who received complete embolization of all genicular arteries (as distinct from embolization of some arteries) (n = 17) with the control group (n = 29) for KOOS and Global Change scores at 12 months. Continuous variables were analyzed with quantile regression, adjusting for baseline scores. Dichotomized variables were analyzed with chi-squared tests. Results. Overall, 58 participants provided questionnaire data at 12 months. No significant differences were found for the primary and secondary outcomes, with both groups improving following the procedure. At 12 months, KOOS pain scores improved by 41.3% and 29.4% in the intervention and control groups, respectively. No adverse events occurred. Subgroup analysis indicated that the complete embolization group had significantly better KOOS Sports and Recreation, KOOS Quality of Life, and Global Change scores than the control group; 76.5% of participants who received complete embolization reporting being moderately or much better compared to 37.9% of the control group. Conclusion. TAE might produce benefits above placebo, but only when complete embolization of all genicular arteries is performed. Further comparative studies are required before definitive conclusions regarding the effectiveness of TAE can be made. Level of evidence: I. Cite this article: Bone Jt Open 2023;4(3):158–167

Abstract. Introduction. Approximately 15–20% of patients report chronic pain three months after total knee replacement (TKR). The STAR care pathway is a clinically important and cost-effective personalised intervention for patients with pain 3 months after TKR. The pathway comprises screening, assesment, onward referral for treatment and follow-up over one year. In a multicentre randomised controlled trial comparing the pathway with usual care, the pathway improved pain at 6 and 12 months. This study examined the longer-term clinical and cost-effectiveness of the STAR care pathway. Methodology. STAR trial participants were followed-up at a median of 4 years post-randomisation. Co-primary outcomes were self-reported pain severity and interference in the replaced knee, assessed with the Brief Pain Inventory (BPI). Resource use from electronic hospital records was valued with UK reference costs. Results. Of the 337 participants active at trial completion, 326 had confirmed vital status, and 226 (69%) provided outcome data at a median of 4 years. The between-group difference in mean BPI severity score was −0.42 (95% CI −1.07, 0.23; p=0.20) and for BPI interference was −0.64 (95% CI −1.41, 0.12; p=0.10), favouring the intervention. Multiple imputation analyses led to attenuations of about 0.2 points. Mean hospital admission costs over four years were £2461.49 (95% CI £1354.42, £3568.57) in the intervention arm and £3791.68 (95% CI £2095.12, to £5488.24) in usual care. Conclusion. These data are consistent with sustained benefits from the STAR care pathway at 4 years, albeit attenuated and with wider confidence intervals, in part attributable to attrition after 1 year

Abstract. Introduction. Challenges in surgical training have led to the exploration of technologies such as augmented reality (AR), which present novel approaches to teaching orthopaedic procedures to medical students. The aim of this double-blinded randomised-controlled trial was to compare the validity and training effect of AR to traditional teaching on medical students’ understanding of total knee arthroplasty (TKA). Methodology. Twenty medical students from 7 UK universities were randomised equally to either intervention or control groups. The control received a consultant-led teaching session and the intervention received training via Microsoft HoloLens, where surgeons were able to project virtual information over physical objects. Participants completed written knowledge and practical exams which were assessed by 2 orthopaedic consultants. Training superiority was established via 4 quantitative outcome measures: OSATS scores, a checklist of TKA-specific steps, procedural time, and written exam scores. Qualitative feedback was evaluated using a 5-point Likert scale. Results. AR training was superior in teaching basic technical proficiency and understanding of TKA, with the intervention group significantly outperforming the control group in 3 metrics [OSATS (38.6%, p=0.021), checklist (33%, p=0.011) and written exam (54.5%, p=0.001)]. Procedural time was equivalent between cohorts (p=0.082). AR was rated as significantly more enjoyable (p=0.044), realistic (p=0.003), easy to understand (p=0.040), and proficient in teaching (p=0.02). Conclusion. In this adequately powered, double-blinded randomised-controlled trial, AR training demonstrated substantially improved translational technical skills and knowledge needed to understand TKA over traditional learning in medical students. Additionally, the results showed face, content, and transfer validity for AR in surgical training

Abstract. Background. Meniscal tears affect 222 per 100,000 of the population and can be managed non-operatively or operatively with an arthroscopic partial meniscectomy (APM), meniscal repair or meniscal transplantation. The purpose of this review is to summarise the outcomes following treatment with a meniscal tear and explore correlations between outcomes. Methodology. A systematic review was performed of MEDLINE, EMBASE, AMED and the Cochrane Central Register of Controlled Trials to identify prospective studies describing the outcomes of patients with a meniscal tear. Comparisons were made of outcomes between APM and non-operative groups. Outcomes were graphically presented over time for all treatment interventions. Pearson's correlations were calculated between outcome timepoints. Results. 35 studies were included, 28 reported outcomes following APM; four following meniscal repair and three following meniscal transplant. Graphical plots demonstrated a sustained improvement for all treatment interventions. A moderate to very strong correlation was reported between baseline and three-month outcomes. In the medium term, there was small significant difference in outcome between APM and non-operative measures (SMD 0.17; 95 % CI 0.04, 0.29), however, this was not clinically significant. Conclusions. Patients with a meniscal tear demonstrated a sustained initial improvement in function scores, which was true of all treatments examined. APM may have little benefit in older people, however, previous trials did not include patients who meet the current indications for surgery as a result the findings should not be generalised to all patients with a meniscal tear. Further trials are required in patients who meet current operative indications

Abstract. Introduction. Secondary osteonecrosis of the knee affects young population and causes bilateral extensive lesions. Arthroplasty is the last resort in younger population and joint preserving options questionable in pathological bone. Conservative measures have shown failure in multiple studies and hence no gold standard treatment advocated. We aimed at identifying and analysing various treatment options for secondary osteonecrosis with respect to the outcomes and studying features of symptomatic secondary osteonecrosis with regards to demographic pattern, radiological features and causative factors. Methods. A systematic review of literature was performed in accordance with the Cochrane handbook for systematic reviews and reported according to the PRISMA guidelines. Results. Six studies which included a total of 192 patients with data on 240 knee joints were included in the final review. Follow up period ranged from 1 year to 16 years. The mean age of the patients was 34.7. 3 studies were on arthroplasty and 3 on joint preserving interventions. Majority of patients were in Stage 2 or Stage 4 of osteonecrosis. Steroid induced osteonecrosis was the majority followed by SLE and sickle cell disease. The pooled analysis showed an improvement of pre-operative knee score from 50.47 to 89.21 post-operatively. The pooled effect size for failure rate was 8.7% in joint preserving interventions and 9.2% in joint replacement group. Conclusion. Joint preserving techniques with bone marrow aspirate infiltration showed promising functional outcome and to a certain extent reversal of the pathological process. For advanced stages with subchondral collapse cemented arthroplasty showed satisfactory functional outcomes

Aims. To perform an incremental cost-utility analysis and assess the impact of differential costs and case volume on the cost-effectiveness of robotic arm-assisted unicompartmental knee arthroplasty (rUKA) compared to manual (mUKA). Methods. This was a five-year follow-up study of patients who were randomized to rUKA (n = 64) or mUKA (n = 65). Patients completed the EuroQol five-dimension questionnaire (EQ-5D) preoperatively, and at three months and one, two, and five years postoperatively, which was used to calculate quality-adjusted life years (QALYs) gained. Costs for the primary and additional surgery and healthcare costs were calculated. Results. rUKA was associated with a relative 0.012 QALY gain at five years, which was associated with an incremental cost per QALY of £13,078 for a unit undertaking 400 cases per year. A cost per QALY of less than £20,000 was achieved when ≥ 300 cases were performed per year. However, on removal of the cost for a revision for presumed infection (mUKA group, n = 1) the cost per QALY was greater than £38,000, which was in part due to the increased intraoperative consumable costs associated with rUKA (£626 per patient). When the absolute cost difference (operative and revision costs) was less than £240, a cost per QALY of less than £20,000 was achieved. On removing the cost of the revision for infection, rUKA was cost-neutral when more than 900 cases per year were undertaken and when the consumable costs were zero. Conclusion. rUKA was a cost-effective intervention with an incremental cost per QALY of £13,078 at five years, however when removing the revision for presumed infection, which was arguably a random event, this was no longer the case. The absolute cost difference had to be less than £240 to be cost-effective, which could be achieved by reducing the perioperative costs of rUKA or if there were increased revision costs associated with mUKA with longer follow-up. Cite this article: Bone Jt Open 2023;4(11):889–898

Aims. Meeting preoperative expectations is known to be of major influence on postoperative satisfaction after total knee arthroplasty (TKA). Improved management of expectation, resulting in more realistic expectations can potentially lead to higher postoperative satisfaction. The objective of this study was to assess the effect of an additional preoperative education module, addressing realistic expectations for long-term functional recovery, on postoperative satisfaction and expectation fulfilment. Methods. In total, 204 primary TKA patients with osteoarthritis were enrolled in this randomized controlled trial (RCT). Patients were allocated to either usual preoperative education (control group) or usual education plus an additional module on realistic expectations (intervention group). Primary outcome was being very satisfied (numerical rating scale for satisfaction ≥ 8) with the treatment result at 12 months' follow-up. Other outcomes were change in preoperative expectations and postoperative expectation fulfilment. Results. A total of 187 patients (91.7%) were available for analysis at follow-up. In the intention-to-treat analysis, 58.5% (55/94) of patients were very satisfied with the treatment result in the control group, and 69.9% (65/93) of patients in the intervention group (adjusted odds ratio (AOR) 1.72, 95% confidence interval (CI) 0.90 to 3.29). A per-protocol analysis for patients who attended the education session (92.0%, n = 172) showed that 56.9% (49/86) of patients were very satisfied in the control group and 74.4% (61/86) in the intervention group (AOR 2.44, 95% CI 1.21 to 4.91). After preoperative education, the expectation scores in the intervention group were significantly lower (mean difference -6.9 (95% CI -10.2 to -3.6)) and did not alter in the control group (mean difference 0.5 (95% CI -2.9 to 3.9)). Overall, fulfilment of expectations at 12 months was significantly higher in the intervention group (mean difference 11.4% (95% CI 2.3 to 20.5)). Conclusion. Improved preoperative patient education can modify patient expectations, resulting in higher postoperative fulfilment of expectation and higher satisfaction in the group that attended the preoperative education. This is the first RCT to confirm the potential of improved expectation management on satisfaction after TKA. Cite this article: Bone Joint J 2021;103-B(4):619–626

Aims. Multiligament knee injuries (MLKI) are devastating injuries that can result in significant morbidity and time away from sport. There remains considerable variation in strategies employed for investigation, indications for operative intervention, outcome reporting, and rehabilitation following these injuries. At present no study has yet provided a comprehensive overview evaluating the extent, range, and overall summary of the published literature pertaining to MLKI. Our aim is to perform a methodologically rigorous scoping review, mapping the literature evaluating the diagnosis and management of MLKI. Methods. This scoping review will address three aims: firstly, to map the current extent and nature of evidence for diagnosis and management of MLKI; secondly, to summarize and disseminate existing research findings to practitioners; and thirdly, to highlight gaps in current literature. A three-step search strategy as described by accepted methodology will be employed to identify peer-reviewed literature including reviews, technical notes, opinion pieces, and original research. An initial limited search will be performed to determine suitable search terms, followed by an expanded search of four electronic databases (MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Web of Science). Two reviewers will independently screen identified studies for final inclusion. Dissemination. We will map key concepts and evidence, and disseminate existing research findings to the wider orthopaedic and sports medicine community, through both peer-reviewed and non-peer-reviewed literature, and conference and in-person communications. We will highlight gaps in the current literature and determine future priorities for further research. Cite this article: Bone Jt Open 2022;3(11):894–897

Aims. The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery. Methods. A total of 76 patients (34 bi-UKA and 42 TKA patients) were analyzed in a prospective, single-centre, randomized controlled trial. Flat ground shod gait analysis was performed preoperatively and one year postoperatively. Knee flexion moment was calculated from motion capture markers and force plates. The same setup determined proprioception outcomes during a joint position sense test and one-leg standing. Surgery allocation, surgeon, and secondary outcomes were analyzed for prediction of the primary outcome from a binary regression model. Results. Both interventions were shown to be effective treatment options, with no significant differences shown between interventions for the primary outcome of this study (18/35 (51.4%) biphasic TKA patients vs 20/31 (64.5%) biphasic bi-UKA patients; p = 0.558). All outcomes were compared to an age-matched, healthy cohort that outperformed both groups, indicating residual deficits exists following surgery. Logistic regression analysis of primary outcome with secondary outcomes indicated that the most significant predictor of postoperative biphasic knee moments was preoperative knee moment profile and trochlear degradation (Outerbridge) (R. 2. = 0.381; p = 0.002, p = 0.046). A separate regression of alignment against primary outcome indicated significant bi-UKA femoral and tibial axial alignment (R. 2. = 0.352; p = 0.029), and TKA femoral sagittal alignment (R. 2. = 0.252; p = 0.016). The bi-UKA group showed a significant increased ability in the proprioceptive joint position test, but no difference was found in more dynamic testing of proprioception. Conclusion. Robotic arm-assisted bi-UKA demonstrated equivalence to TKA in achieving a biphasic gait pattern after surgery for osteoarthritis of the knee. Both treatments are successful at improving gait, but both leave the patients with a functional limitation that is not present in healthy age-matched controls. Cite this article: Bone Joint J 2022;103-B(4):433–443

Aims. The tibial component of total knee arthroplasty can either be an all-polyethylene (AP) implant or a metal-backed (MB) implant. This study aims to compare the five-year functional outcomes of AP tibial components to MB components in patients aged over 70 years. Secondary aims are to compare quality of life, implant survivorship, and cost-effectiveness. Methods. A group of 130 patients who had received an AP tibial component were matched for demographic factors of age, BMI, American Society of Anesthesiologists (ASA) grade, sex, and preoperative Knee Society Score (KSS) to create a comparison group of 130 patients who received a MB tibial component. Functional outcome was assessed prospectively by KSS, quality of life by 12-Item Short-Form Health Survey questionnaire (SF-12), and range of motion (ROM), and implant survivorships were compared. The SF six-dimension (6D) was used to calculate the incremental cost effectiveness ratio (ICER) for AP compared to MB tibial components using quality-adjusted life year methodology. Results. The AP group had a mean KSS-Knee of 83.4 (standard deviation (SD) 19.2) and the MB group a mean of 84.9 (SD 18.2; p = 0.631), while mean KSS-Function was 75.4 (SD 15.3) and 73.2 (SD 16.2 p = 0.472), respectively. The mental (44.3 vs 45.1; p = 0.464) and physical (44.8 vs 44.9; p = 0.893) dimensions of the SF-12 and ROM (97.9° vs 99.7°; p = 0.444) were not different between the groups. Implant survivorship at five years were 99.2% and 97.7% (p = 0.321). The AP group had a greater SF-6D gain of 0.145 compared to the MB group, with an associated cost saving of £406, which resulted in a negative ICER of -£406/0.145 = -£2,800. Therefore, the AP tibial component was dominant, being a more effective and less expensive intervention. Conclusion. There were no differences in functional outcomes or survivorship at five years between AP and MB tibial components in patients aged 70 years and older, however the AP component was shown to be more cost-effective. In the UK, only 1.4% of all total knee arthroplasties use an AP component; even a modest increase in usage nationally could lead to significant financial savings. Cite this article: Bone Jt Open 2022;3(12):969–976

Aims. The aim of this study was to evaluate the cost-effectiveness of arthroscopic partial meniscectomy versus physical therapy plus optional delayed arthroscopic partial meniscectomy in young patients aged under 45 years with traumatic meniscal tears. Methods. We conducted a multicentre, open-labelled, randomized controlled trial in patients aged 18 to 45 years, with a recent onset, traumatic, MRI-verified, isolated meniscal tear without knee osteoarthritis. Patients were randomized to arthroscopic partial meniscectomy or standardized physical therapy with an optional delayed arthroscopic partial meniscectomy after three months of follow-up. We performed a cost-utility analysis on the randomization groups to compare both treatments over a 24-month follow-up period. Cost utility was calculated as incremental costs per quality-adjusted life year (QALY) gained of arthroscopic partial meniscectomy compared to physical therapy. Calculations were performed from a healthcare system perspective and a societal perspective. Results. A total of 100 patients were included: 49 were randomized to arthroscopic partial meniscectomy and 51 to physical therapy. In the physical therapy group, 21 patients (41%) received delayed arthroscopic partial meniscectomy during follow-up. Over 24 months, patients in the arthroscopic partial meniscectomy group had a mean 0.005 QALYs lower quality of life (95% confidence interval -0.13 to 0.14). The cost-utility ratio was €-160,000/QALY from the healthcare perspective and €-223,372/QALY from the societal perspective, indicating that arthroscopic partial meniscectomy incurs additional costs without any added health benefit. Conclusion. Arthroscopic partial meniscectomy is arthroscopic partial meniscectomy is unlikely to be cost-effective in treating young patients with isolated traumatic meniscal tears compared to physical therapy as a primary health intervention. Arthroscopic partial meniscectomy leads to a similar quality of life, but higher costs, compared to physical therapy plus optional delayed arthroscopic partial meniscectomy. Cite this article: Bone Joint J 2023;105-B(11):1177–1183

Aims. Despite new technologies for total knee arthroplasty (TKA), approximately 20% of patients are dissatisfied. A major reason for dissatisfaction and revision surgery after TKA is persistent pain. The radiological grade of osteoarthritis (OA) preoperatively has been investigated as a predictor of the outcome after TKA, with conflicting results. The aim of this study was to determine if there is a difference in the intensity of pain 12 months after TKA in relation to the preoperative radiological grade of OA alone, and the combination of the intensity of preoperative pain and radiological grade of OA. Methods. The preoperative data of 300 patients who underwent primary TKA were collected, including clinical information (age, sex, preoperative pain), psychological variables (depression, anxiety, pain catastrophizing, anticipated pain), and quantitative sensory testing (temporal summation, pressure pain thresholds, conditioned pain modulation). The preoperative radiological severity of OA was graded according to the Kellgren-Lawrence (KL) classification. Persistent pain in the knee was recorded 12 months postoperatively. Generalized linear models explored differences in postoperative pain according to the KL grade, and combined preoperative pain and KL grade. Relative risk models explored which preoperative variables were associated with the high preoperative pain/low KL grade group. Results. Pain 12 months after TKA was not associated with the preoperative KL grade alone. Significantly increased pain 12 months after TKA was found in patients with a combination of high preoperative pain and a low KL grade (p = 0.012). Patients in this group were significantly more likely to be male, younger, and have higher preoperative pain catastrophizing, higher depression, and lower anxiety (all p ≤ 0.05). Conclusion. Combined high preoperative pain and low radiological grade of OA, but not the radiological grade alone, was associated with a higher intensity of pain 12 months after primary TKA. This group may have a more complex cause of pain that requires additional psychological interventions in order to optimize the outcome of TKA. Cite this article: Bone Joint J 2022;104-B(11):1202–1208

Aims. This study aims to evaluate a new home medical stretching device called the Self Treatment Assisted Knee (STAK) tool to treat knee arthrofibrosis. Methods. 35 patients post-major knee surgery with arthrofibrosis and mean range of movement (ROM) of 68° were recruited. Both the STAK intervention and control group received standard physiotherapy for eight weeks, with the intervention group additionally using the STAK at home. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Scores (OKS) were collected at all timepoints. An acceptability and home exercise questionnaire capturing adherence was recorded after each of the interventions. Results. Compared to the control group, the STAK intervention group made significant gains in mean ROM (30° versus 8°, p < 0.0005), WOMAC (19 points versus 3, p < 0.0005), and OKS (8 points versus 3, p < 0.0005). The improvements in the STAK group were maintained at long-term follow-up. No patients suffered any complications relating to the STAK, and 96% of patients found the STAK tool ‘perfectly acceptable’. Conclusion. The STAK tool is effective in increasing ROM and reducing pain and stiffness. Patients find it acceptable and adherence to treatment was high. This study indicates that the STAK tool would be of benefit in clinical practice and may offer a new, cost-effective treatment for arthrofibrosis. Cite this article: Bone Joint Open 2020;1-8:465–473