Aims. The James Lind Alliance aims to bring patients, carers, and clinicians together to identify uncertainties regarding care. A Priority Setting Partnership was established by the British Association for Surgery of the Knee in conjunction with the James Lind Alliance to identify research priorities related to the assessment, management, and rehabilitation of patients with persistent symptoms after knee arthroplasty. Methods. The project was conducted using the James Lind Alliance protocol. A steering group was convened including patients, surgeons, anaesthetists, nurses, physiotherapists, and researchers. Partner organizations were recruited. A survey was conducted on a national scale through which patients, carers, and healthcare professionals submitted key unanswered questions relating to problematic knee arthroplasties. These were analyzed, aggregated, and synthesized into summary questions and the relevant evidence was checked. After confirming that these were not answered in the current literature, 32 questions were taken forward to an interim prioritization survey. Data from this survey informed a shortlist taken to a final consensus meeting. Results. A total of 769 questions were received during the initial survey with national reach across the UK. These were refined into 32 unique questions by an independent information specialist. The interim prioritization survey was completed by 201 respondents and 25 questions were taken to a final consensus group meeting between patients, carers, and healthcare professionals. Consensus was reached for ranking the top ten questions for publication and dissemination. Conclusions. The top ten research priorities focused on pain, infection, stiffness, health service configuration, surgical and non-surgical management strategies, and outcome measures. This list will guide funders and help focus research efforts within the knee arthroplasty community. Cite this article: Bone Joint J 2020;102-B(9):1176–1182

The aim of this study was to examine the functional outcome at ten years following lateral closing wedge high tibial osteotomy for medial compartment osteoarthritis of the knee and to define pre-operative predictors of survival and determinants of functional outcome. . 164 consecutive patients underwent high tibial osteotomy between 2000 and 2002. A total of 100 patients (100 knees) met the inclusion criteria and 95 were available for review at ten years. Data were collected prospectively and included patient demographics, surgical details, long leg alignment radiographs, Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and Knee Society scores (KSS) pre-operatively and at five and ten years follow-up. At ten years, 21 patients had been revised at a mean of five years. Overall Kaplan–Meier survival was 87% (95% confidence interval (CI) 81 to 94) and 79% (95% CI 71 to 87) at five and ten years, respectively. When compared with unrevised patients, those who had been revised had significantly lower mean pre-operative WOMAC Scores (47 (21 to 85) vs 65 (32 to 99), p < 0.001), higher mean age (54 yrs (42 to 61) vs 49 yrs (26 to 66), p = 0.006) and a higher mean BMI (30.2; 25 to 39 vs 27.9; 21 to 36, p = 0.005). Each were found to be risk factors for revision, with hazard ratios of 10.7 (95% CI 4 to 28.6; pre-operative WOMAC < 45), 6.5 (95% CI 2.4 to 17.7; age > 55) and 3.0 (95%CI 1.2 to 7.6; BMI > 30). Survival of patients with pre-operative WOMAC > 45, age < 55 and BMI < 30 was 97% at five and ten years. WOMAC and KSS in surviving patients improved significantly between pre-operative (mean 61; 32 to 99) and five (mean 88; 35 to 100, p = 0.001) and ten years (mean 84; 38 to 100, p = 0.001). Older patients had better functional outcomes overall, despite their higher revision rate. This study has shown that improved survival is associated with age < 55 years, pre-operative WOMAC scores > 45 and, a BMI < 30. In patients over 55 years of age with adequate pre-operative functional scores, survival can be good and functional outcomes can be significantly better than their younger counterparts. We recommend the routine use of pre-operative functional outcome scores to guide decision-making when considering suitability for high tibial osteotomy. Cite this article: Bone Joint J 2014;96-B:1491–7

Abstract

Aims. The purpose of the present study was to examine the long-term fixation of a cemented fixed-bearing polished titanium tibial baseplate (Genesis ll). . Patients and Methods. Patients enrolled in a previous two-year prospective trial (n = 35) were recalled at ten years. Available patients (n = 15) underwent radiostereometric analysis (RSA) imaging in a supine position using a conventional RSA protocol. Migration of the tibial component in all planes was compared between initial and ten-year follow-up. Outcome scores including the Knee Society Score, Western Ontario and McMaster Universities Arthritis Index, 12-item Short Form Health Survey, Forgotten Joint Score, and University of California, Los Angeles Activity Score were recorded. Results. At ten years, the mean migration of the tibial component was less than 0.1 mm and 0.1° in all planes relative to the post-operative RSA exam. Maximum total point movement increased with time (p = 0.002) from 0.23 mm (. sd. 0.18) at six weeks to 0.42 mm (. sd. 0.20) at ten years. Conclusion. The low level of tibial baseplate migration found in the present study correlates to the low rate of revision for this implant as reported in individual studies and in joint replacement registries. Take home message: Overall, the implant was found to be well fixed at ten years, supporting its continued clinical use and the predictive power of RSA for determining long-term fixation of implants. Cite this article: Bone Joint J 2016;98-B:616–21

Introduction. The causes of revision total knee replacement are varied. There is a subset of these revision cases (poly wear and some cases of instability for example) where the ability to retain the metal femoral and tibial components and replacing just the polyethylene is an appealing option. We report on a series of RTKR where only the poly insert was replaced and the patients were followed for a minimum of ten years. Materials and Methods. Our study group consisted of 64 consecutive non infected RTKR patients who underwent a revision of the polyethylene alone between 1998 and 2006. All patients had been treated originally with the same cemented, CR, patella resurfaced primary TKR. Reasons for revision were 51 poly wear and/or osteolysis, 7 instability, and 6 other. The average time from the primary to the revision surgery was 9.1 years (range 2.2 to 16.1 years). All patients had an isolated poly liner change. No femurs or tibial trays were revised. Average age of the cohort at revision was 72.2 (range 48 to 88). Average BMI was 31.9 (range 23.6 to 43.9). There were 36 female patients. Of the group, 42 were ASA 1 or 2 and 22 were ASA 3. Pre-op alignment averaged 6.0 (range 2 varus to 8 valgus). Patients were followed for a minimum of 10 years (range 10 to 19 years). Results. At final follow up 13 patients had died, none were lost to follow up leaving 51 patients available for review. There were 7 reoperations in 6 patients (7 knees). Reasons for reoperation were: 4 aseptic tibial loosening at an average of 4.1 years (range 1.2 to 8.3) following first poly revision, two for polywear at an average 9 years post first poly revision, and one for deep infection (5.6 years post first poly revision). Knee society scores at 6 weeks post revision was 93.5 (range 38 to 100) and at final follow up for the non-revised knees was 91.6 (range 36 to 100). Conclusion. In appropriate settings, where the femoral and tibial components are satisfactorily aligned and well fixed and the soft tissues can be balanced, a poly change alone can provide a durable solution for the revision total knee patient. The ability to retain the metal components has advantages in terms of patient morbidity and cost

We reviewed the outcome of 146 Insall-Burstein II total knee replacements carried out in 121 patients over a period of nearly four years in a general orthopaedic unit. At a mean follow-up of ten years, 94 knees in 78 patients were available for review. Six patients (7 knees) were lost to follow-up and 37 (45 knees) had died. The clinical outcome using the scoring system of the Hospital for Special Surgery (HSS) was excellent or good in 79% of patients, fair in 14% and poor in 7%. The mean preoperative HSS score was 31, improving to 79 at the latest review. Using the newer rating system of the Knee Society, the mean score at ten years was 87 and the mean functional score 56. The arc of flexion improved from a mean preoperative value of 88° to 100°. The 18 patients who had had a previous high tibial osteotomy were analysed separately and were found to have benefited equally from the operation. Nine prostheses were revised, giving a cumulative survival rate of 92.3% at ten years. Radiological evaluation of 104 radiographs showed radiolucent lines around ten tibial components, none of which required revision. Anterior knee pain was a significant problem

There have been several reports of good survivorship and excellent function at ten years with fixed-bearing unicompartmental knee replacement. However, little is known about survival beyond ten years. From the Bristol database of over 4000 knee replacements, we identified 203 St Georg Sled unicompartmental knee replacements (174 patients) which had already survived ten years. The mean age of the patients at surgery was 67.1 years (35.7 to 85) with 67 (38.5%) being under 65 years at the time of surgery. They were reviewed at a mean of 14.8 years (10 to 29.4) from surgery to determine survivorship and function. There were 99 knees followed up for 15 years, 21 for 20 years and four for 25 years. The remainder failed, were withdrawn, or the patient had died. In 58 patients (69 knees) the implant was in situ at the time of death. Revision was undertaken in 16 knees (7.9%) at a mean of 13 years (10.2 to 21.6) after operation. In seven knees (3.4%) this was for progression of arthritis, in three (1.5%) for wear of polyethylene, in four (2%) for tibial loosening, in two (1%) for fracture of the femoral component and in two (1%) for infection. Two knees (1%) were revised for more than one reason. The mean Bristol knee score of the surviving knees fell from 86 (34 to 100) to 79 (42 to 100) during the second decade. Survivorship to 20 years was 85.9% (95% CI 82.9% to 88.9%) and at 25 years was 80% (95% CI 70.2% to 89.8%). Satisfactory survival of a fixed-bearing unicompartmental knee replacement can be achieved into the second decade and beyond

Aim. To assess the ten year subjective knee function and activity level following four-strand semitendinosis and gracilis (STG) anterior cruciate ligament reconstruction. Methods. 86 patients underwent anterior cruciate reconstruction by two knee surgeons in the year 1999. 80 patients meet the inclusion criteria of STG reconstruction by a standard operative technique. Patient evaluation was by completion of a Lysholm Knee Score and Tegner Activity Level Scale at a minimum of ten years from reconstructive surgery. This was by initial postal questionnaire and subsequent telephone follow-up. Results. 80 patients underwent anterior cruciate reconstruction with average age 30.9 years +/− 8.8 (15 to 58 years). There was a 77.5% (62 patients) response at ten years to the questionnaire. The mean Lysholm Knee Score at ten years was 78.4 +/− 12.8 (39 to 90). The mean activity level had decreased from 8.3 to 5.3 at ten years according to the Tegner Activity Scale. 11 patients required medial and lateral partial menisectomies at the time of original reconstruction. This group of patients had a Lysholm Knee Score of 67.6 +/− 19.1 and Tegner Activity Scale of 3.9 at ten years following reconstruction. 17 of the 80 patients (21.25%) required re-operation because of further knee symptoms, with 4 patients requiring revision of the anterior cruciate following re-rupture. Conclusion. Anterior Cruciate Ligament Reconstruction with four-strand STG hamstring graft provides a reliable method of restoring knee function with a 5% revision rate for re-rupture at ten years. Combined partial medial and lateral menisectomy at the time of the initial reconstruction is a poor prognostic indicator for function at ten years

This single-blinded randomised controlled trial investigated whether one design of mobile-bearing (MB) total knee replacement (TKR) has any advantage over a fixed-bearing (FB) design on long-term fixation as measured by radiostereometry. The amount of wear underneath the mobile bearing was also evaluated. A series of 42 knees was randomised to MB or FB tibial components with appropriate polyethylene inserts and followed for between ten and 12 years, or until the death of the patient. The polyethylene in the MB group was superior in that it was gamma-irradiated in inert gas and was calcium-stearate free; the polyethylene in the FB group was gamma-irradiated in air and contained calcium stearate. In theory this should be advantageous to the wear rate of the MB group. At final follow-up the overall mean migration was 0.75 mm (. sd. 0.76) in the MB group and 0.66 mm (. sd. 0.4) in the FB group, with the FB group demonstrating more posterior tilt and the MB group more internal rotation. In the FB group there was one revision for aseptic loosening, but none in the MB group. There were no significant differences in clinical or radiological scores. . For the MB group, the mean linear wear rate on the under-surface was 0.026 mm/year (. sd.  0.014). This was significantly smaller than the wear rate of 0.11 mm/year (. sd. 0.06) in the MB between femur and polyethylene (p < 0.001). Nevertheless, even in a best-case setting the mobile bearings of this TKR design had no apparent advantage in terms of fixation over the FB knee prosthesis at ten to 12 years. The wear underneath the mobile bearing was small and is unlikely to be clinically relevant

Aims

The aim of this study was to establish the results of isolated exchange of the tibial polyethylene insert in revision total knee arthroplasty (RTKA) in patients with well-fixed femoral or tibial components. We report on a series of RTKAs where only the polyethylene was replaced, and the patients were followed for a mean of 13.2 years (10.0 to 19.1).

Introduction

Cementless fixation in total knee arthroplasty has been proposed to offer advantages long-term once osteointegration has occurred as there is no substrate between the implant and the bone to fail. Radiostereometric analysis (RSA) is a useful tool to study fixation, but typically focused on early migration in the first two post-operative years. Few studies have looked at 10-year RSA migration in cementless fixation and those that have contain small numbers of subjects. The objective of this study was to compare implant migration and inducible displacement between cemented and cementless TKA at 10 years and to compare the 10-year migration to the 2-year data in an effort to validate the predictive modelling of RSA.

Stress shielding resulting in diminished bone density following total knee replacement (TKR) may increase the risk of migration and loosening of the prosthesis. This retrospective study was designed to quantify the effects of the method of fixation on peri-prosthetic tibial bone density beneath cemented and uncemented tibial components of similar design and with similar long-term survival rates. Standard radiographs taken between two months and 15 years post-operatively were digitised from a matched group of TKRs using cemented (n = 67) and uncemented (n = 67) AGC tibial prostheses. Digital radiograph densitometry was used to quantify changes in bone density over time. Age, length of follow-up, gender, body mass index and alignment each significantly influenced the long-term pattern of peri-prosthetic bone density. Similar long-term changes in density irrespective of the method of fixation correlated well with the high rate of survival of this TKR at 20 years, and suggest that cemented and uncemented fixation are both equally viable.

Cite this article: Bone Joint J 2013;95-B:911–16.

Aims. The aim of this study was to determine whether obesity had a detrimental effect on the long-term performance and survival of medial unicompartmental knee arthroplasties (UKAs). Methods. This study reviewed prospectively collected functional outcome scores and revision rates of all medial UKA patients with recorded BMI performed in Christchurch, New Zealand, from January 2011 to September 2021. Patient-reported outcome measures (PROMs) were the primary outcome of this study, with all-cause revision rate analyzed as a secondary outcome. PROMs were taken preoperatively, at six months, one year, five years, and ten years postoperatively. There were 873 patients who had functional scores recorded at five years and 164 patients had scores recorded at ten years. Further sub-group analysis was performed based on the patient’s BMI. Revision data were available through the New Zealand Joint Registry for 2,323 UKAs performed during this time period. Results. Obese patients (BMI > 30 kg/m. 2. ) were 3.1 years younger than non-obese patients (BMI < 30 kg/m. 2. ) at the time of surgery (mean age of obese patients 65.5 years (SD 9.7) and mean age of non-obese patients 68.6 years (SD 10.1)). Preoperatively, obese patients tended to have significantly lower functional scores than non-obese patients, which continued at five and ten years postoperatively. At these timepoints, obese patients had significantly lower scores for most PROMs measured compared to non-obese patients. However, there was no significant difference in the improvement of any of these scores after surgery between obese and non-obese patients. There was no significant difference in revision rates between obese and non-obese patients at any time. All-cause revision rate for obese patients was 0.73 per 100 observed component years compared to 0.67 in non-obese patients at ten years. There was also no significant difference in the aseptic loosening rate between groups. Conclusion. Our study supports the use of UKAs in obese patients, with similar benefit and survival compared to non-obese patients at ten years

Aims. This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up. Methods. From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed. Results. At 15 years, 28 patients were lost to follow-up (6.1%) and 221 patients (51.9%) had died, with the mean age of the remaining cohort reducing by four years. PROMs response rates among surviving patients were: one-year 63%; five-year 72%; ten-year 94%; and 15-year 59%. OKS and SF-12 scores changed significantly over 15 years (p < 0.001). The mean improvement in OKS was 18.8 (95% confidence (CI) 16.7 to 19.0) at one year. OKS peaked at five years (median 43 years) declining thereafter (p < 0.001), though at 15 years it remained 17.5 better than preoperatively. Age and sex did not alter this trajectory. A quarter of patients experienced a clinically significant decline (≥ 7) in OKS from five to ten years and from ten to 15 years. The SF-12 physical component score displayed a similar trajectory, peaking at one year (p < 0.001). Patient satisfaction was 88% at one, five, and ten years, and 94% at 15 years. In all, 15-year Kaplan-Meier survival was 97.6% (95% CI 96.0% to 99.2%) for any revision, and 98.9% (95% CI 97.9% to 99.9%) for aseptic revision. Conclusion. Improvements in PROMs were significant and maintained following single radius TKA, with OKS peaking at five years, and generic physical health peaking at one year. Patient satisfaction remained high at 15 years, at which point 2.4% had been revised. Cite this article: Bone Jt Open 2023;4(10):808–816

Aims. We have previously reported the mid-term outcomes of revision total knee arthroplasty (TKA) for flexion instability. At a mean of four years, there were no re-revisions for instability. The aim of this study was to report the implant survivorship and clinical and radiological outcomes of the same cohort of of patients at a mean follow-up of ten years. Methods. The original publication included 60 revision TKAs in 60 patients which were undertaken between 2000 and 2010. The mean age of the patients at the time of revision TKA was 65 years, and 33 (55%) were female. Since that time, 21 patients died, leaving 39 patients (65%) available for analysis. The cumulative incidence of any re-revision with death as a competing risk was calculated. Knee Society Scores (KSSs) were also recorded, and updated radiographs were reviewed. Results. The cumulative incidence of any re-revision was 13% at a mean of ten years. At the most recent-follow-up, eight TKAs had been re-revised: three for recurrent flexion instability (two fully revised to varus-valgus constrained implants (VVCs), and one posterior-stabilized (PS) implant converted to VVC, one for global instability (PS to VVC), two for aseptic loosening of the femoral component, and two for periprosthetic joint infection). The ten-year cumulative incidence of any re-revision for instability was 7%. The median KSS improved significantly from 45 (interquartile range (IQR) 40 to 50) preoperatively to 70 (IQR 45 to 80) at a mean follow-up of ten years (p = 0.031). Radiologically, two patients, who had not undergone revision, had evidence of loosening (one tibial and one patellar). The remaining components were well fixed. Conclusion. We found fair functional outcomes and implant survivorship at a mean of ten years after revision TKA for flexion instability with a PS implant. Recurrent instability and aseptic loosening were the most common indications for re-revision. Components with increased constraint, such as a VVC or hinged, should be used in these patients in order to reduce the risk of recurrent instability. Cite this article: Bone Joint J 2022;104-B(10):1126–1131

Aims. To identify unanswered questions about the prevention, diagnosis, treatment, and rehabilitation and delivery of care of first-time soft-tissue knee injuries (ligament injuries, patella dislocations, meniscal injuries, and articular cartilage) in children (aged 12 years and older) and adults. Methods. The James Lind Alliance (JLA) methodology for Priority Setting Partnerships was followed. An initial survey invited patients and healthcare professionals from the UK to submit any uncertainties regarding soft-tissue knee injury prevention, diagnosis, treatment, and rehabilitation and delivery of care. Over 1,000 questions were received. From these, 74 questions (identifying common concerns) were formulated and checked against the best available evidence. An interim survey was then conducted and 27 questions were taken forward to the final workshop, held in January 2023, where they were discussed, ranked, and scored in multiple rounds of prioritization. This was conducted by healthcare professionals, patients, and carers. Results. The top ten included questions regarding prevention, diagnosis, treatment, and rehabilitation. The number one question was, ‘How urgently do soft-tissue knee injuries need to be treated for the best outcome?’. This reflects the concerns of patients, carers, and the wider multidisciplinary team. Conclusion. This validated process has generated ten important priorities for future soft-tissue knee injury research. These have been submitted to the National Institute for Health and Care Research. All 27 questions in the final workshop have been published on the JLA website. Cite this article: Bone Joint J 2024;106-B(3):232–239

Aims. The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes. Methods. A retrospective consecutive study of all patients who underwent a rTKA using the fully cemented SMILES rotating hinge prosthesis between 2005 to 2018. Outcome measures included aseptic loosening, reoperations, revision for any cause, complications, and survivorship. Patients and implant survivorship data were identified through both prospectively collected local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival analysis was used at ten years. Results. Overall, 69 consecutive patients (69 knees) were included with a median age of 78 years (interquartile range 69 to 84), and there were 46 females (66.7%). Indications were septic revisions in 26 (37.7%), and aseptic aetiology in the remining 43 (62.3%). The mean follow-up was 9.7 years (4 to 18), and the overall complication was rate was 7.24%, all with patellofemoral complications. Failure rate with ‘any cause revision’ was 5.8%. There was one case of aseptic loosening of the femoral component. At ten years, 17/69 patients (24.63%) had died, and implant survivorship was 92.2%. Conclusion. In our experience, the SMILES rotating hinge prosthesis achieves satisfactory long-term outcomes with ten-year implant survivorship of 92.2% and a patellofemoral complication rate of 7.24%. Cite this article: Bone Jt Open 2023;4(10):776–781

Aims. Unicompartmental knee arthroplasty (UKA) has higher revision rates than total knee arthroplasty (TKA). As revision of UKA may be less technically demanding than revision TKA, UKA patients with poor functional outcomes may be more likely to be offered revision than TKA patients with similar outcomes. The aim of this study was to compare clinical thresholds for revisions between TKA and UKA using revision incidence and patient-reported outcomes, in a large, matched cohort at early, mid-, and late-term follow-up. Methods. Analyses were performed on propensity score-matched patient cohorts of TKAs and UKAs (2:1) registered in the New Zealand Joint Registry between 1 January 1999 and 31 December 2019 with an Oxford Knee Score (OKS) response at six months (n, TKA: 16,774; UKA: 8,387), five years (TKA: 6,718; UKA: 3,359), or ten years (TKA: 3,486; UKA: 1,743). Associations between OKS and revision within two years following the score were examined. Thresholds were compared using receiver operating characteristic analysis. Reasons for aseptic revision were compared using cumulative incidence with competing risk. Results. Fewer TKA patients with ‘poor’ outcomes (≤ 25) subsequently underwent revision compared with UKA at six months (5.1% vs 19.6%; p < 0.001), five years (4.3% vs 12.5%; p < 0.001), and ten years (6.4% vs 15.0%; p = 0.024). Compared with TKA, the relative risk for UKA was 2.5-times higher for ‘unknown’ reasons, bearing dislocations, and disease progression. Conclusion. Compared with TKA, more UKA patients with poor outcomes underwent revision from early to long-term follow-up, and were more likely to undergo revision for ‘unknown’ reasons, which suggest a lower clinical threshold for UKA. For UKA, revision risk was higher for bearing dislocations and disease progression. There is supporting evidence that the higher revision UKA rates are associated with lower clinical thresholds for revision and additional modes of failure. Cite this article: Bone Joint J 2023;105-B(3):269–276

Aims. Both the femoral and tibial component are usually cemented at revision total knee arthroplasty (rTKA), while stems can be added with either cemented or press-fit (hybrid) fixation. The aim of this study was to compare the long-term stability of rTKA with cemented and press-fitted stems, using radiostereometric analysis (RSA). Methods. This is a follow-up of a randomized controlled trial, initially involving 32 patients, of whom 19 (nine cemented, ten hybrid) were available for follow-up ten years postoperatively, when further RSA measurements were made. Micromotion of the femoral and tibial components was assessed using model-based RSA software (RSAcore). The clinical outcome was evaluated using the Knee Society Score (KSS), the Knee injury and Osteoarthritis Outcome Score (KOOS), and visual analogue scale (pain and satisfaction). Results. The median total femoral translation and rotation at ten years were 0.39 mm (interquartile range (IQR) 0.20 to 0.54) and 0.59° (IQR 0.46° to 0.73°) for the cemented group and 0.70 mm (IQR 0.15 to 0.77) and 0.78° (IQR 0.47° to 1.43°) for the hybrid group. For the tibial components this was 0.38 mm (IQR 0.33 to 0.85) and 0.98° (IQR 0.38° to 1.34°) for the cemented group and 0.42 mm (IQR 0.30 to 0.52) and 0.72° (IQR 0.62° to 0.82°) for the hybrid group. None of these values were significantly different between the two groups and there were no significant differences between the clinical scores in the two groups at this time. There was only one re-revision, in the hybrid group, for infection and not for aseptic loosening. Conclusion. These results show good long-term fixation with no difference in micromotion and clinical outcome between fully cemented and hybrid fixation in rTKA, which builds on earlier short- to mid-term results. The patients all had type I or II osseous defects, which may in part explain the good results. Cite this article: Bone Joint J 2022;104-B(7):875–883

Aims. Total knee arthroplasty (TKA) with a highly congruent condylar-stabilized (CS) articulation may be advantageous due to increased stability versus cruciate-retaining (CR) designs, while mitigating the limitations of a posterior-stabilized construct. The aim was to assess ten-year implant survival and functional outcomes of a cemented single-radius TKA with a CS insert, performed without posterior cruciate ligament sacrifice. Methods. This retrospective cohort study included consecutive patients undergoing TKA at a specialist centre in the UK between November 2010 and December 2012. Data were collected using a bespoke electronic database and cross-referenced with national arthroplasty audit data, with variables including: preoperative characteristics, intraoperative factors, complications, and mortality status. Patient-reported outcome measures (PROMs) were collected by a specialist research team at ten years post-surgery. There were 536 TKAs, of which 308/536 (57.5%) were in female patients. The mean age was 69.0 years (95% CI 45.0 to 88.0), the mean BMI was 32.2 kg/m. 2. (95% CI 18.9 to 50.2), and 387/536 (72.2%) survived to ten years. There were four revisions (0.7%): two deep infections (requiring debridement and implant retention), one aseptic loosening, and one haemosiderosis. Results. Kaplan-Meier analysis demonstrated no difference in implant survival according to sex, age, or obesity status. Ten-year PROMs were available for 196/387 (50.6%) surviving patients and were excellent: mean Oxford Knee Score 34.4 (95% CI 32.7 to 36.1); mean Forgotten Joint Score (FJS) 51.2 (95% CI 16.1 to 86.3); mean EuroQol five-dimension five-level questionnaire score 69.9 (95% CI 46.8 to 93.0); 141/196 (71.9%) achieved the 22-point FJS patient-acceptable symptom state (PASS); and 156/196 (79.6%) were “very satisfied or satisfied”. Conclusion. This is the only large study reporting ten-year implant survival and functional outcomes of TKA using a cemented single-radius design and with a CS tibial bearing construct. The findings of excellent implant survival, safety, and functional outcomes indicate that this combination is a safe and effective option in routine TKA. Further investigation of this single-radius design TKA with CS tibial bearings with well-matched patient study groups will allow further insight into the performance of these implants. Cite this article: Bone Joint J 2024;106-B(8):808–816