Aims. To compare time dependent functional improvement for patients with medial, respectively lateral knee osteoarthritis (OA) after treatment with opening wedge osteotomy relieving the pressure on the osteoarthritic part of the knee. Methods. In all, 49 patients (52 knees) with a mean age of 47 years (31 to 64) underwent high tibial osteotomies (HTO), and 24 patients with a mean age of 48 years (31 to 62) low femoral osteotomies (LFO) with opening wedge technique due to medial, respectively lateral knee OA with malalignment. All osteotomies were stabilized with a Puddu plate and bone grafting performed in the same time period (2000 to 2008). The patients were evaluated by the Knee Injury and Osteoarthritis Outcome Score (KOOS) pre-operatively and at six months, and at one, two, five, and ten years postoperatively. The knee OA was graded according to the Ahlbäck and Kellgren-Lawrence radiological scoring systems. Results. The mean angular corrections were 8.0° (4° to 12°) for the HTO and 9.6° (4° to 20°) for the LFO. Both the pre-operative KOOS and the osteoarthritic gradings were similar for the two patient groups. The five subscores of KOOS increased significantly during the postoperative period (p < 0.001 to 0.029) levelling out after one year in both groups. The KOOS subscore symptoms was significantly higher for patients with HTO than those with LFO at all follow-up times, for sport and recreation in the period one to five years, and for pain and quality of life at two to five years (p < 0.001 to 0.009). Eight HTOs (15%) and five LFOs (21%) were converted to total knee arthroplasty after mean 6.7 years (2.0 to 9.8) and 5.4 years (4.0 to 8.0) respectively. The ten-year osteotomy survival rates were 88% for the HTO and 79% for the LFO (p = 0.745). Conclusion. Patients with unicompartmental knee OA improved after a corrective opening wedge osteotomy, but four of the five subscores of KOOS were significantly higher for those with medial than those with lateral OA in most of the ten-year follow-up period. Cite this article: Bone Joint Open 2020;1-7:346–354

Aims. Knee osteoarthritis (OA) is characterized by a chronic inflammatory process involving multiple cytokine pathways, leading to articular cartilage degeneration. Intra-articular therapies using pharmaceutical or autologous anti-inflammatory factors offer potential non-surgical treatment options. Autologous protein solution (APS) is one such product that uses the patient’s blood to produce a concentrate of cells and anti-inflammatory cytokines. This study evaluated the effect of a specific APS intra-articular injection (nSTRIDE) on patient-reported outcome measures compared to saline in moderate knee OA. Methods. A parallel, double-blinded, placebo-controlled randomized controlled trial was conducted, where patients with unilateral moderate knee OA (Kellgren-Lawrence grade 2 or 3) received either nSTRIDE or saline (placebo) injection to their symptomatic knee. The primary outcome was the difference in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score at 12 months post-intervention. Secondary outcomes included WOMAC component scores, Knee injury and Osteoarthritis Outcome Score (KOOS), and visual analogue scale (VAS) scores at all follow-up timepoints (three, six, and 12 months). Results. A total of 40 patients were analyzed (21 nSTRIDE; 19 saline) in the study. No significant difference was found between nSTRIDE and saline groups for WOMAC total score at 12 months (mean difference -10.4 (95% CI -24.4 to 3.6; p = 0.141). There were no significant differences in WOMAC or KOOS scores across all timepoints. VAS scores favoured the saline group for both rest and worst pain scales at 12 months post-injection (mean difference (worst) 12 months 21.5 (95% CI 6.2 to 36.8; p = 0.008); mean difference (rest) 12 months 17.8 (95% CI 2.2 to 33.4; p = 0.026)). There were no adverse events recorded in either study group. Conclusion. Our study demonstrates no significant differences between nSTRIDE and saline groups in KOOS and WOMAC scores over time. Notably, APS injection resulted in significantly worse pain symptoms at 12 months compared to saline injection. Cite this article: Bone Joint J 2024;106-B(9):907–915

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

Aims. The patient-acceptable symptom state (PASS) is a level of wellbeing, which is measured by the patient. The aim of this study was to determine if the proportion of patients who achieved an acceptable level of function (PASS) after medial unicompartmental knee arthroplasty (UKA) was different based on the status of the anterior cruciate ligament (ACL) at the time of surgery. Methods. A total of 114 patients who underwent UKA for isolated medial osteoarthritis (OA) of the knee were included in the study. Their mean age was 65 years (SD 10). No patient underwent a bilateral procedure. Those who had undergone ACL reconstruction during the previous five years were excluded. The Knee injury Osteoarthritis Outcome Score Activities of Daily Living (KOOS ADL) function score was used as the primary outcome measure with a PASS of 87.5, as described for total knee arthroplasty (TKA). Patients completed all other KOOS subscales, Lysholm score, the Western Ontario and McMaster Universities Osteoarthritis Index, and the Veterans Rand 12-item health survey score. Failure was defined as conversion to TKA. Results. Survivorship at ten years was 97% in both the ACL-deficient and ACL-intact groups. The mean survival was 16.1 years (95% confidence interval (CI) 15.3 to 16.8) for the ACL-deficient group and 15.6 years (95% CI 14.8 to 16.361) for the ACL-intact group (p = 0.878). At a mean of nine years (SD 3.5) in the ACL-deficient group, 32 patients (87%) reached the PASS for the KOOS ADL. In the ACL-intact group, at a mean of 8.6 years (SD 3) follow-up, 63 patients (85%) reached PASS for the KOOS ADL. There was no significant difference in the percentage of patients who reached PASS for all KOOS subscales and Lysholm between the two groups. Conclusion. PASS was achieved in 85% of all UKAs for KOOS ADL, similar to reports for TKA. Fixed-bearing, medial, non-robotically-assisted UKA resulted in 97% survival at ten years in both the ACL-deficient and ACL-intact groups. There was no significant difference in all outcomes between the two groups. Understanding PASS will allow better communication between surgeons and patients to improve the surgical management of patients with single compartment OA of the knee. This study provides mid- to long-term data supporting the use of PASS to document outcomes following UKA. PASS was met in more than 85% of patients with no differences between ACL-deficient and ACL-intact knees at a mean follow-up of nine years. Cite this article: Bone Joint J 2021;103-B(8):1367–1372

Aims. The purpose of this study was to develop a personalized outcome prediction tool, to be used with knee arthroplasty patients, that predicts outcomes (lengths of stay (LOS), 90 day readmission, and one-year patient-reported outcome measures (PROMs) on an individual basis and allows for dynamic modifiable risk factors. Methods. Data were prospectively collected on all patients who underwent total or unicompartmental knee arthroplasty at a between July 2015 and June 2018. Cohort 1 (n = 5,958) was utilized to develop models for LOS and 90 day readmission. Cohort 2 (n = 2,391, surgery date 2015 to 2017) was utilized to develop models for one-year improvements in Knee Injury and Osteoarthritis Outcome Score (KOOS) pain score, KOOS function score, and KOOS quality of life (QOL) score. Model accuracies within the imputed data set were assessed through cross-validation with root mean square errors (RMSEs) and mean absolute errors (MAEs) for the LOS and PROMs models, and the index of prediction accuracy (IPA), and area under the curve (AUC) for the readmission models. Model accuracies in new patient data sets were assessed with AUC. Results. Within the imputed datasets, the LOS (RMSE 1.161) and PROMs models (RMSE 15.775, 11.056, 21.680 for KOOS pain, function, and QOL, respectively) demonstrated good accuracy. For all models, the accuracy of predicting outcomes in a new set of patients were consistent with the cross-validation accuracy overall. Upon validation with a new patient dataset, the LOS and readmission models demonstrated high accuracy (71.5% and 65.0%, respectively). Similarly, the one-year PROMs improvement models demonstrated high accuracy in predicting ten-point improvements in KOOS pain (72.1%), function (72.9%), and QOL (70.8%) scores. Conclusion. The data-driven models developed in this study offer scalable predictive tools that can accurately estimate the likelihood of improved pain, function, and quality of life one year after knee arthroplasty as well as LOS and 90 day readmission. Cite this article: Bone Joint J 2020;102-B(9):1183–1193

Abstract. High tibial osteotomy (HTO) is a well-recognised procedure to address medial compartment osteoarthritis (OA). There remains dispute on the impact of pre-operative patient factors on patient related outcome measures (PROMS). Does BMI and age affect > 2 year and > 5 year oxford knee scores (OKS) and Knee injury and osteoarthritis outcome scores (KOOS). A retrospective review of a prospectively collected database was performed. Timeframe was 26/6/2014 and 25/8/2022. BMI and age were recorded. OKS and KOOS were collected at > 2 years and > 5 years. There were 81 procedures included, of these 50 had OKS and KOOS scores at > 2 years and 35 at > 5 years. Median BMI was 28.5kg/m. 2. , range was 18.6–40.8kg/m. 2. Spearman's rank for >2 year OKS was p(df)=−0.210 p=0.157, > 5 year OKS p(df)=−0.215 p=0.230. For > 2 year and > 5 year KOOS subscales there were no statistically significant associations on Spearman's rank. For age, median age was 52.5, range 26–71 years old. OKS at >2 year p(df)=0.068 p=0.664, OKS >5 years p(df)=0.065 p= 0.709. For >2 year and > 5 year KOOS subscales there were no statistically significant associations on Spearman's rank. There were no adverse outcome in patients up-to the age of 71. There were no statistically significant Spearman's rank correlations between PROMS and OKS/KOOS scores. This supports recent KOG consensus statement highlighting physiological age importance vs chronological age. Of note there were more negative associations in the BMI group compared with age

Introduction. Patient satisfaction is an important outcome measure after total knee arthroplasty (TKA) and is the ultimate goal of surgery. However, patient satisfaction reflects a complex construct of the patient's personal expectations and preferences in addition to subjective evaluation of outcome after TKA. Multiple studies have found a patient dissatisfaction rate of approximately 20% at 1 year after TKA. The purpose of this study is to determine whether there is an association between a single-item validated TKA satisfaction score and patient-reported outcome measures (PROMs) at 3 time points (1, 2, and 5 years after TKA) and to determine if dissatisfaction rate after TKA varies over time. Methods. A multi-center, prospective cohort of 12,952 patients (8,078 patients were assessed at 1-year, 702 patients at 2-year, and 4,172 patients at 5-year) undergoing primary TKA were enrolled by 230 surgeons in 28 states between 2012–2015. Surgeons practices varied in size, reimbursement models, and geographic setting ensuring that the cohort included diverse patient populations and delivery models. Surgeons agreed to invite all TKA patients to participate and sporadic audits of surgical logs validated that all patients were invited and > 90% of patients were included. Demographic and clinical data [age, gender, body mass index (BMI), and modified Charlson co-morbidity index (CCI)] were collected. Patient-reported outcome measures (PROMs) were collected pre-op and post-op at 1, 2, and 5 years using an internet-based platform including the KOOS (total score, and pain, ADL, QoL sub scores), KOOS Jr, SF-36 (PCS and MCS). We used the single-item satisfaction scale which was tested and validated by the Swedish Knee Arthroplasty Registry. The patients' responses were made on 5-point Likert scale (very satisfied, somewhat satisfied, neutral, somewhat dissatisfied, very dissatisfied). Patients were classified into 2 categories: satisfied group for patients who answered satisfied or very satisfied and dissatisfied group for patients answered neutral, somewhat dissatisfied, or very dissatisfied. Univariate analysis of the difference between the satisfied and dissatisfied patients' groups was performed using Mann-Whitney U test for continuous variables and chi-square test for categorical variables. Logistic regression model was performed to study the correlation between the satisfaction and PROMs with 95% confidence interval. Results. Mean age was 66.6 years, 62.7% were female, and mean BMI was 31.6. The CCI was 0 in 55.1%, 1 in 22%, 2–5 in 12.6% and ≥ 6 in 10.3%. Cumulative revision rate was 1.29% at 2 years. The 30-day adverse events incidence was 2.5% while the 90-day adverse events incidence was 4.7%. The dissatisfaction rate was 18.1% at 1-year, 11.5% at 2-year, and 8.5% at 5-year (P<0.001, Chi-square). Dissatisfaction significantly affects younger patients (<55 years) (P=0.04, Chi-square) and patients with high Charlson comorbidity index >1 (P=0.001, Chi-square). Low post-operative KOOS Pain, KOOS ADL, KOOS total score, KOOS JR, SF-36 PCS, and SP-36 MCS scores were significantly associated with dissatisfaction (P<0.001). At 5 years follow-up, in patients with KOOS scores greater than 70, 1.3% of patients were dissatisfied; with KOOS 50–70, 16.3% were dissatisfied and when KOOS < 50, 62.2% are dissatisfied. Logistic regression showed significant correlation of satisfaction with postoperative KOOS pain, KOOS ADL, KOOS QoL, KOOS total score, KOOS JR, and SF-36 PCS (P< 0.001) at 1-year, 2-year, and at 5-year. The MCS was correlated with patient satisfaction only at 1-year (P< 0.001). Conclusion. The patient dissatisfaction rate 5 years after TKA is 8.1% in FORCE-TJR patients which is significantly lower than 18.1% at 1-year. Less improvement of PROM scores after TKA are significantly associated with patient dissatisfaction. Postoperative PROM scores are associated with patient satisfaction at 1-year, 2-years, and 5-years. When the 5-year post- op KOOS total score is >70, 98.7% of patients are satisfied and only 1.3% are dissatisfied. Patient satisfaction is an important outcome measure after TKA that can be determined by asking a single question. However, in order to understand why a patient is dissatisfied, KOOS scores (KOOS pain, KOOS ADL, KOOS QoL) that assess specific postoperative outcomes can assist in determining the reason for patient dissatisfaction after TKA

Aims. This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS). Methods. Patients scheduled for primary TKA were included in a single-centre, prospective, three-armed, blinded randomized trial (n = 216; 72 per group). After intraoperative confirmation of posterior cruciate ligament (PCL) integrity, patients were randomly allocated to receive a CR, AS, or PS design from the same TKA system. Insertion of an AS or PS design required PCL resection. The primary outcome was the mean score of all five subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS) at two-year follow-up. Secondary outcomes included all KOOS subscales, Oxford Knee Score, EuroQol five-dimension health questionnaire, EuroQol visual analogue scale, range of motion (ROM), and willingness to undergo the operation again. Patient satisfaction was also assessed. Results. Patients reported similar levels of pain, function, satisfaction, and general health regardless of the prosthetic design they received. Mean maximal flexion (129° (95% confidence interval (CI) 127° to 131°) was greater in the PS group than in the CR (120° (95% CI 121° to 124°)) and AS groups (122° (95% CI 120° to 124°)). Conclusion. Despite differences in design and constraint, CR, AS, and PS designs from a single TKA system resulted in no differences in patient-reported outcomes at two-year follow-up. PS patients had statistically better ROM, but the clinical significance of this finding is unclear. Cite this article: Bone Joint J 2023;105-B(12):1271–1278

Abstract. Introduction. Meniscal repair is an accepted surgical option for meniscal tears. However, there remains trepidation with regard to offering such surgery to older patients. We aim to evaluate the outcomes in these such patients. Methodology. A single surgeons log was used to identify patients who underwent meniscal repair and were over the age of 40. Patients having concurrent anterior cruciate ligament reconstructions were excluded. Demographic data, surgical data and outcomes (pain visual analogue score (VAS); single assessment numerical evaluation (SANE) and knee injury and osteoarthritis outcome joint replacement (KOOS Jr) score) were collected prospectively. Final outcomes were collected between 6–12 months following surgery. Results. 24 meniscal tears in 22 knees (22 patients) were identified. Mean age was 52.2 (range; 40.6-70.3). Morphology of the tears were medial meniscus posterior root tear 10 (42%); medial meniscus posterior horn tear 9 (38%); lateral meniscus posterior horn tear 2 (8.3%); lateral meniscus posterior root tear 1 (4.2%); lateral meniscus body tear 1 (4.2%) and lateral meniscus anterior horn tear 1 (4.2%). Response rate was 86%. Statistically significant improvements in pain VAS (p=0.0001); SANE (p=0.0001) and KOOS Jr Score (p=0.0005) were found. 68% and 74% of patients had surpassed the MCID in their KOOS symptoms and KOOS quality of life subscales, respectively. Conclusion. Meniscal repair in patients over 40 years of age is an acceptable treatment with significant improvements in patients reported outcome measures, SANE and pain VAS

Aims. The purpose of this multicentre observational study was to investigate the association between intraoperative component positioning and soft-tissue balancing on short-term clinical outcomes in patients undergoing robotic-arm assisted unicompartmental knee arthroplasty (UKA). Patients and Methods. Between 2013 and 2016, 363 patients (395 knees) underwent robotic-arm assisted UKAs at two centres. Pre- and postoperatively, patients were administered Knee Injury and Osteoarthritis Score (KOOS) and Forgotten Joint Score-12 (FJS-12). Results were stratified as “good” and “bad” if KOOS/FJS-12 were more than or equal to 80. Intraoperative, post-implantation robotic data relative to CT-based components placement were collected and classified. Postoperative complications were recorded. Results. Following exclusions and losses to follow-up, 334 medial robotic-arm assisted UKAs were assessed at a mean follow-up of 30.0 months (8.0 to 54.9). None of the measured parameters were associated with overall KOOS outcome. Correlations were described between specific KOOS subscales and intraoperative, post-implantation robotic data, and between FJS-12 and femoral component sagittal alignment. Three UKAs were revised, resulting in 99.0% survival at two years (95% confidence interval (CI) 97.9 to 100.0). Conclusion. Although little correlation was found between intraoperative robotic data and overall clinical outcome, surgeons should consider information regarding 3D component placement and soft-tissue balancing to improve patient satisfaction. Reproducible and precise placement of components has been confirmed as essential for satisfactory clinical outcome. Cite this article: Bone Joint J 2019;101-B:435–442

Aims. This study compares the PFC total knee arthroplasty (TKA) system in a prospective randomized control trial (RCT) of the mobile-bearing rotating-platform (RP) TKA against the fixed-bearing (FB) TKA. This is the largest RCT with the longest follow-up where cruciate-retaining PFC total knee arthroplasties are compared in a non-bilateral TKA study. Patients and Methods. A total of 167 patients (190 knees with 23 bilateral cases), were recruited prospectively and randomly assigned, with 91 knees receiving the RP and 99 knees receiving FB. The mean age was 65.5 years (48 to 82), the mean body mass index (BMI) was 29.7 kg/m. 2. (20 to 52) and 73 patients were female. The Knee Society Score (KSS), Knee Society Functional Score (KSFS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and 12-Item Short-Form Health Survey Physical and Mental Component Scores (SF-12 PCS, SF-12 MCS) were gathered and recorded preoperatively, at five-years’ follow-up, and at ten years’ follow-up. Additionally, Knee Injury and Osteoarthritis Outcome Scores (KOOS) were collected at five- and ten-year follow-ups. The prevalence of radiolucent lines (RL) on radiographs and implant survival were recorded at five- and ten-year follow-ups. Results. At the ten-year follow-up, the RP group (n = 39) had a statistically significant superior score in the OKS (p = 0.001), WOMAC (p = 0.023), SF-12 PCS (p = 0.019), KOOS Activities of Daily Living (ADL) (p = 0.010), and KOOS Sport and Recreation (Sport/Rec) (p = 0.006) compared with the FB group (n = 46). The OKS, SF-12 PCS, and KOOS Sport/Rec at ten years had mean scores above the minimal clinically important difference (MCID) threshold. There was no significant difference in prevalence of radiolucency between groups at five-years’ follow-up (p = 0.449), nor at ten-years’ follow-up (p = 0.08). Implant survival rate at 14 years postoperative was 95.2 (95% CI 90.7 to 99.8) and 94.7 (95% CI 86.8 to 100.0) for the RP and FB TKAs, respectively. Conclusion. At ten-year follow-up, the mobile-bearing knee joint arthroplasty had statistically and clinically relevant superior OKS, SF-12 PCS, and KOOS (Sport/Rec) than the fixed-bearing platform. No difference was seen in prevalence of radiolucent lines. There was a greater than 94% implant survival rate for both cohorts at 14 years. Cite this article: Bone Joint J 2018;100-B:1336–44

Aims. Meniscal allograft transplantation (MAT) for patients with symptomatic meniscal loss has demonstrated good clinical results and survivorship. Factors that affect both functional outcome and survivorship have been reported in the literature. These are typically single-centre case series with relatively small numbers and conflicting results. Our aim was to describe an international, two-centre case series, and identify factors that affect both functional outcome and survival. Methods. We report factors that affect outcome on 526 patients undergoing MAT across two sites (one in the UK and one in Italy). Outcomes of interest were the Knee injury and Osteoarthritis Outcome Score four (KOOS4) at two years and failure rates. We performed multiple regression analysis to examine for factors affecting KOOS, and Cox proportional hazards models for survivorship. Results. Our results indicate that baseline KOOS4 score affects functional outcome at two years, but no other included factors were significantly related to functional outcome. The only factor that affected failure rate was the presence of cartilage lesions down to bone on both the femur and tibia, decreasing the five-year survivorship from 95% (95% confidence interval (CI) 91 to 99) to 84% (95% CI 74 to 94). Conclusion. To our knowledge, this is the largest international cohort reporting on MAT. Our results indicate that factors such as age, BMI, and cartilage lesions down to bone on both the femur and tibia of the affected compartment should not present barriers to offering MAT. Baseline KOOS4 score and the presence of bone-on-bone arthritis can be used to help counsel patients regarding the expected risks and rewards of surgery. Cite this article: Bone Joint J 2022;104-B(6):657–662

Aims. The aim of this study was to report patient and clinical outcomes following robotic-assisted total knee arthroplasty (RA-TKA) at multiple institutions with a minimum two-year follow-up. Methods. This was a multicentre registry study from October 2016 to June 2021 that included 861 primary RA-TKA patients who completed at least one pre- and postoperative patient-reported outcome measure (PROM) questionnaire, including Forgotten Joint Score (FJS), Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS JR), and pain out of 100 points. The mean age was 67 years (35 to 86), 452 were male (53%), mean BMI was 31.5 kg/m. 2. (19 to 58), and 553 (64%) cemented and 308 (36%) cementless implants. Results. There were significant improvements in PROMs over time between preoperative, one- to two-year, and > two-year follow-up, with a mean FJS of 17.5 (SD 18.2), 70.2 (SD 27.8), and 76.7 (SD 25.8; p < 0.001); mean KOOS JR of 51.6 (SD 11.5), 85.1 (SD 13.8), and 87.9 (SD 13.0; p < 0.001); and mean pain scores of 65.7 (SD 20.4), 13.0 (SD 19.1), and 11.3 (SD 19.9; p < 0.001), respectively. There were eight superficial infections (0.9%) and four revisions (0.5%). Conclusion. RA-TKA demonstrated consistent clinical results across multiple institutions with excellent PROMs that continued to improve over time. With the ability to achieve target alignment in the coronal, axial, and sagittal planes and provide intraoperative real-time data to obtain balanced gaps, RA-TKA demonstrated excellent clinical outcomes and PROMs in this patient population. Cite this article: Bone Jt Open 2022;3(7):589–595

Abstract. Introduction. Double-level knee osteotomy (DLO) is a challenging procedure that requires precision in preoperative planning and intraoperative execution to achieve the desired correction. It is indicated in cases of severe varus or valgus deformities where a single-level osteotomy would yield significantly tilted joint line obliquity (JLO). Methods. A single-centre, retrospective analysis of prospectively collected data for 26 patients, who underwent DLO by PSCGs for valgus malaligned knees. Post-operative alignment was evaluated and the delta for different lower limb alignment parameters were calculated; HKA, MPTA, and LDFA. At the two-year follow-up, changes in KOOS sub-scores, UCLA scores, lower limb discrepancy, and mean time to return to work and sport were recorded. All intraoperative and postoperative complications were recorded. Results. The postoperative mean ΔHKA was 0.9 ± 0.9°, the mean ΔMPTA was 0.7 ± 0.7°, and the mean ΔLDFA was 0.7 ± 0.8° (all values with p > 0.05). All KOOS subscores’ mean values were improved to an extent two-fold superior to the reported MCID (all with p < 0.0001). There was a significant increase in the UCLA score at the final follow-up (5.4 ± 1.5 preoperatively versus 7.7 ± 1.4, p < 0.01). The mean time to return to sport and work was 4.7 ± 1.1 and 4.3 ± 2.1 months, respectively. There was an improvement in Lower-limb discrepancy preoperative (LLD = 1.3+/−2cm) to postoperative measures (LLD= 0.3 +/− 0.4 cm) p=0.02. Conclusion. DLO is effective and safe in achieving accurate correction in bifocal valgus malaligned knees with maintained lower limb length and low complication rate with no compromise of JLO

Abstract. Methodology. Prospective single-surgeon case-series evaluating patients undergoing surgery by this technique. 76 cases (mean age of 33.2 years) who had primary ACL reconstruction with BTB or quadriceps tendon with bone block, were divided into 2 matched groups (age, sex and type of graft) of 38 each based on the method of femoral fixation used (interference screw or adjustable cortical suspension). Patients were followed up clinically and using PROMS from NLR with EQ-5D, KOOS, IKDC and Tegner scores. Complications and return to theatre were noted. Paired two-tailed student t-tests and Chi-square tests were employed for statistical analysis. Results. At a mean follow-up of 82 months, peri-operative mean EQ-5D VAS, EQ-5D Index, KOOS, IKDC and Tegner activity scores showed significant improvement (p<0.05), but no significant difference between the two groups (p>0.05). Mean graft length and diameter was 77mm and 9.3 respectively. Mean interval from injury to surgery was 10.5 months. 18(23.7%) patients had associated meniscal tear with 73.3 % undergoing repair. 10 cases (13.2 %) returned to theatre including, MUA for arthrofibrosis (n=2) and intra-substance graft failure (n=2). 3 cases had to be converted to interference screw fixation due to the tightrope cutting through from the femoral bone block as a result of a technical pitfall. Conclusion. Primary ACL reconstruction using adjustable cortical suspension on femoral side for BTB or quadriceps bone-block tendon graft is a safe technique with added advantages of 360 degree bone ingrowth and no screw in the femoral tunnel

Introduction. The aim of this study was to evaluate the effects of posterior tibial slope (PTS) and posterior condylar offset (PCO) on patient-reported pain and function one year after TKA. Methods. A total of 500 patients from 11 clinics in 6 countries were enrolled into a prospective, multicenter study. All patients were indicated for primary TKA for OA and received components from a single manufacturer. All liners were made from vitamin-E stabilized, highly crosslinked (95 kGy) polyethylene; 54.7% were posterior stabilized (PS) and the remaining were cruciate-retaining. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was administered at the one-year follow-up visit. The KOOS pain and activities in daily life (ADL) sub-scores were dichotomized and served as the primary outcomes. Dichotomization was done with the patient acceptable symptom state (PASS), defined by previous studies as the value of the PROM above which patients deem their state as acceptable (84.5 points for KOOS pain and 83.0 points for KOOS ADL). Plain lateral radiographs were taken and assessed for PTS (Figure 1) and PCO (Figure 2). PTS was categorized as above (excessive flexion), within (ideal), or below (extension) the safe zone of 0° − 7° of flexion. PCO increases or decreases of greater than 3mm were compared against no change (≤ 3mm). Each of the two sagittal positioning metrics was tested against the KOOS pain and ADL PASS at one year. Results. 396 patients (80.3% of eligible) had completed the one-year visit. A total of 297 (75%) achieved the PASS in KOOS pain and 277 (70%) achieved the PASS in KOOS ADL (Figure 3). PTS was closely associated with the likelihood of achieving the PASS in KOOS pain (p < 0.001) and ADL (p = 0.005) in univariate tests (Kruskal-Wallis). It was also independently predictive of achieving the PASS in multivariable models controlling for sex, body mass index, preoperative health state, and age. In a binary logistic regression for achieving the PASS in KOOS pain, a PTS < 0° (extension) was 6.3 times less likely to achieve the PASS compared to the ideal PTS (0°–7° of flexion) (p=0.004; OR=0.16). Overly flexed tibial components (>7°) were equally likely to achieve the PASS in KOOS pain as components with an ideal PTS (p=0.091). A separate model assessing independent predictors of achieving the PASS in KOOS ADL, patients with extension were 4.8 times less likely to achieve the PASS compared to those with an ideal PTS (p=0.012; OR=0.21), while patients with excessive flexion were equally likely to achieve the PASS in KOOS ADL as patients with an ideal PTS (p=0.077). When considering the patients with a PTS > 7° (excessive flexion), PCO decrease was associated with a lower chance of achieving the PASS in KOOS ADL (p = 0.022). When considering the patients with a PTS < 0° (extension), PCO increase was associated with a lower chance of achieving the PASS in KOOS pain (p = 0.031). Conclusions. The most influential sagittal positioning parameter affecting patient outcomes at one year after TKA was PTS. PTS had a significant, independent effect on all PROMs one year after TKA. Surgeons should be more cautious to avoid tibial component extension rather than excessive flexion. We recommend replicating the native PCO and targeting a PTS of 0°–7° of flexion. For any figures or tables, please contact authors directly

Aims. The purpose is to determine the non-inferiority of a smartphone-based exercise educational care management system after primary knee arthroplasty compared with a traditional in-person physiotherapy rehabilitation model. Methods. A multicentre prospective randomized controlled trial was conducted evaluating the use of a smartphone-based care management system for primary total knee arthroplasty (TKA) and partial knee arthroplasty (PKA). Patients in the control group (n = 244) received the respective institution’s standard of care with formal physiotherapy. The treatment group (n = 208) were provided a smartwatch and smartphone application. Early outcomes assessed included 90-day knee range of movement, EuroQoL five-dimension five-level score, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) score, 30-day single leg stance (SLS) time, Time up and Go (TUG) time, and need for manipulation under anaesthesia (MUA). Results. Overall, 90-day mean flexion was not significantly different between the control (121° (SD 11.7°)) and treatment groups (121. o. ; p = 0.559); 90-day mean SLS was 22.7 seconds (SD 9.8) in controls and 24.3 seconds (SD 20.8) in treatment (p = 0.519); 90-day mean TUG times were 10.1 seconds (SD 4.8) in control and 9.3 seconds (SD 3.3) in treatment (p = 0.139). Mean KOOS JR scores were significantly different between control group (73.6 (SD 13.4)) and treatment group (70.4 (SD 12.6); p = 0.026). MUAs were performed in nine (3.7%) patients in the control group and four (1.9%) in the treatment group (p = 0.398). Physiotherapy was performed by 230 (94.4%) of control group and 123 (59.3%) of treatment group (p < 0.001). There were no significant differences between groups in postoperative urgent care visits, or readmissions within 90 days, with significantly fewer emergency department visits in the treatment group (16 (8.2%) vs five (2.5%), p = 0.014). Conclusion. The use of the smartwatch/smartphone care platform demonstrated non-inferiority of clinically significant outcomes to traditional care models, while requiring significantly less postoperative physiotherapy and fewer emergency department visits. This platform could aid in decreasing postoperative costs, while improving patient engagement and communication with the healthcare team. Cite this article: Bone Joint J 2021;103-B(6 Supple A):3–12

Aims. Neither a surgeon’s intraoperative impression nor the parameters of computer navigation have been shown to be predictive of the outcomes following total knee arthroplasty (TKA). The aim of this study was to determine whether a surgeon, with robotic assistance, can predict the outcome as assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain (KPS), one year postoperatively, and establish what factors correlate with poor KOOS scores in a well-aligned and balanced TKA. Methods. A total of 134 consecutive patients who underwent TKA using a dynamic ligament tensioning robotic system with a tibia first resection technique and a cruciate sacrificing ultracongruent TKA system were enrolled into a prospective study. Each TKA was graded based on the final mediolateral ligament balance at 10° and 90° of flexion: 1) < 1 mm difference in the thickness of the tibial insert and that which was planned (n = 75); 2) < 1 mm difference (n = 26); 3) between 1 mm to 2 mm difference (n = 26); and 4) > 2 mm difference (n = 7). The mean one-year KPS score for each grade of TKA was compared and the likelihood of achieving an KPS score of > 90 was calculated. Finally, the factors associated with lower KPS despite achieving a high-grade TKA (grade A and B) were analyzed. Results. Patients with a grade of A or B TKA had significantly higher mean one-year KPS scores compared with those with C or D grades (p = 0.031). There was no difference in KPS scores in grade A or B TKAs, but 33% of these patients did not have a KPS score of > 90. While there was no correlation with age, sex, preoperative deformity, and preoperative KOOS and Patient-Reported Outcomes Measurement Information System (PROMIS) physical scores, patients with a KPS score of < 90, despite a grade A or B TKA, had lower PROMIS mental health scores compared with those with KPS scores of > 90 (54.1 vs 50.8; p = 0.043). Patients with grade A and B TKAs with KPS > 90 were significantly more likely to respond with “my expectations were too low”, and with “the knee is performing better than expected” compared with patients with these grades of TKA who had a KPS score of < 90 (40% vs 22%; p = 0.004). Conclusion. A TKA balanced with robotic assistance to within 1 mm of difference between the medial and lateral sides in both flexion and extension had a higher KPS score one year postoperatively. Despite accurate ligament balance information, a robotic system could not guarantee excellent pain relief. Patient expectations and mental status also significantly affected the perceived success of TKA. Cite this article: Bone Joint J 2021;103-B(6 Supple A):67–73

Aims. Meniscal allograft transplantation is undertaken to improve pain and function in patients with a symptomatic meniscal deficient knee compartment. While case series have shown improvements in patient reported outcome measures (PROMs), its efficacy has not been rigorously evaluated. This study aimed to compare PROMs in patients having meniscal transplantation with those having personalized physiotherapy at 12 months. Patients and Methods. A single-centre assessor-blinded, comprehensive cohort study, incorporating a pilot randomized controlled trial (RCT) was performed on patients with a symptomatic compartment of the knee in which a (sub)total meniscectomy had previously been performed. They were randomized to be treated either with a meniscal allograft transplantation or personalized physiotherapy, and stratified for malalignment of the limb. They entered the preference groups if they were not willing to be randomized. The Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score and Lysholm score and complications were collected at baseline and at four, eight and 12 months following the interventions. Results. A total of 36 patients entered the study; 21 were randomized and 15 chose their treatments. Their mean age was 28 years (range 17 to 46). The outcomes were similar in the randomized and preference groups, allowing pooling of data. At 12 months, the KOOS. 4. composite score (mean difference 12, p = 0.03) and KOOS subscales of pain (mean difference 15, p = 0.02) and activities of daily living (mean difference 18, p = 0.005) were significantly superior in the meniscal transplantation group. Other PROMs also favoured this group without reaching statistical significance. There were five complications in the meniscal transplantation and one in the physiotherapy groups. Conclusion. This is the first study to compare meniscal allograft transplantation to non-operative treatment. The results provide the best quality evidence to date of the symptomatic benefits of meniscal allograft transplantation in the short term, but a multicentre RCT is required to investigate this question further. Cite this article: Bone Joint J 2018;100-B:56–63

Aims. Cementless total knee arthroplasty (TKA) offers the potential for strong biological fixation compared with cemented TKA where fixation is achieved by the mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs, which have used additive manufacturing (3D printing). The aim of this study was to present mid-term clinical outcomes and implant survivorship of the cementless Stryker Triathlon Tritanium TKA. Methods. This was a single institution registry review of prospectively gathered data from 341 cementless Triathlon Tritanium TKAs at four to 6.8 years follow-up. Outcomes were determined by comparing pre- and postoperative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores, and pre- and postoperative 12-item Veterans RAND/Short Form Health Survey (VR/SF-12) scores. Aseptic loosening and revision for any reason were the endpoints which were used to determine survivorship at five years. Results. At mid-term follow-up, the mean KOOS JR score improved significantly from 33.14 (0 t0 85, standard deviation (SD) 21.88) preoperatively to 84.12 (15.94 to 100, SD 20.51) postoperatively (p < 0.001), the mean VR/SF-12 scores improved significantly from physical health (PH), 31.21 (SD 5.32; 23.99 to 56.77) preoperatively to 42.62 (SD 10.72; 19.38 to 56.82) postoperatively (p < 0.001) and the mental health (MH), 38.15 (SD 8.17; 19.06 to 60.75) preoperatively to 55.09 (SD 9.64; 19.06 to 66.98) postoperatively (p < 0.001). A total of 11 revisions were undertaken, with an overall revision rate of 2.94%, including five for periprosthetic joint infection (1.34%), three for loosening (0.80%), two for instability (0.53%), and one for pain (0.27%). The overall survivorship was 97.06% and survivorship for aseptic loosening as the endpoint was 98.40%, with a 99.5% survivorship of the 3D-printed tibial component. Conclusion. This 3D-printed cementless total knee system shows excellent survivorship at mid-term follow-up. This design and the ability to obtain cementless fixation offers promise for excellent long-term durability. Cite this article: Bone Joint J 2021;103-B(6 Supple A):32–37