Aims: The Oxford Knee Score (OKS) is an established and validated outcome measure of knee arthroplasty (KA), but it is not clear how responses to each of the 12 questions relate to satisfaction. The aim was to assess which of 12 OKS questions were associated with patient satisfaction after KA.Methods: This single-centre retrospective cohort study was conducted over an eight-year period from January 2014 to December 2021. A total of 3,361 patients completed preoperative and six months postoperative OKS. The mean age was 69.9 years (34 to 94, SD 9.3), and 1,792 were female (55.0%). Patient satisfaction with their KA was assessed at six months, which was categorized into satisfied (satisfied, very satisfied) and dissatisfied (neutral, dissatisfied, very dissatisfied).Results: All 12 questions demonstrated significant improvements postoperatively (p < 0.001), with moderate (q2/3/7) to large (q1/4/5/6/8/9/10/11/12) effect sizes. There were 2,704 patients (82.9%) who were satisfied with their KA at six months. Satisfied patients had significantly greater improvements (p < 0.001) in each of the OKS questions, with the greatest differences found in questions 6 (limping; mean difference (MD) 1.41 (95% CI 1.29 to 1.53)) and 1 (pain; MD 1.32 (95% CI 1.22 to 1.42)). Preoperative responses to each of the OKS questions demonstrated poor discriminatory ability to predict patient satisfaction (area under the curve < 0.70). Improvement in questions 1 (pain; odds ratio (OR) 1.72 (95% CI 1.51 to 1.96), p < 0.001), 6 (limping; OR 1.28 (95% CI 1.16 to 1.41), p < 0.001), 7 (kneeling; OR 1.20 (95% CI 1.06 to 1.35), p = 0.003), 8 (night pain; OR 1.11 (95% CI 1.01 to 1.23), p = 0.038), 9 (working; OR 1.21 (95% CI 1.05 to 1.39), p = 0.015), and 12 (stairs; OR 1.42 (95% CI 1.25 to 1.63), p < 0.001) were independently associated with satisfaction.Conclusion: Improvements in six of the 12 OKS questions were independently associated with patient satisfaction; these could be prioritized as areas to be addressed following KA, and modification of related patient expectations may improve satisfaction with surgery.Cite this article: Bone Jt Open 2025;6(8):983–990.

Aims: Unicompartmental knee arthroplasty (UKA) is associated with an accelerated recovery, improved functional outcomes, and retention of anatomical knee kinematics when compared to manual total knee arthroplasty (mTKA). UKA is not universally employed by all surgeons as there is a higher revision risk when compared to mTKA. Robotic arm-assisted (ra) UKA enables the surgeon to position the prosthesis more accurately when compared to manual UKA, and is associated with improved functional outcomes and a lower early revision risk. Non-randomized data suggests that, when compared to mTKA, raUKA has a clinically meaningful greater functional benefit. This protocol describes a randomized controlled trial that aims to evaluate the clinical and cost-effectiveness of raUKA compared to mTKA for individuals with isolated medial compartment osteoarthritis (OA).Methods: The total versus robotic-assisted unicompartmental knee arthroplasty (TRAKER) trial is a patient- and assessor-blinded, pragmatic parallel two-arm randomized superiority trial of adults undergoing elective primary knee arthroplasty for primary medial compartment OA at a single NHS hospital (ClinicalTrials.gov NCT05290818). Participants will be randomly allocated on a 1:2 basis to either raUKA or mTKA, respectively. The primary analysis will compare the Oxford Knee Score (OKS) six months after surgery. Secondary outcomes measured at three, six, and 12 months include the OKS, Forgotten Joint Score, patient expectations, EuroQol five-dimension questionnaire (EQ-5D), and EQ-visual analogue scale (EQ-VAS), patient satisfaction, range of motion, postoperative complications, need for further surgery, resource use, and financial costs. Cost-effectiveness will be measured over a ten-year time span. A total of 159 patients will be randomized (n = 53 raUKA vs n = 106 mTKA) to obtain 80% power to detect a five-point difference in OKS between the groups six months after surgery.Conclusion: The trial findings will provide evidence about the clinical and cost-effectiveness of raUKA compared to mTKA in patients with isolated medial compartment OA. This will inform future National Institute for Health and Care Excellence guidelines on primary knee arthroplasty in the UK.Cite this article: Bone Jt Open 2025;6(2):164–177.

Background: Patient-reported outcome measures (PROMs) are important after hip fracture but can impose respondent burden. A simple global measure may provide complementary information about a patient’s overall perception of hip normality. The Normal Hip Score (NHS) is a single-item 0–100 measure of perceived hip normality. This study evaluated preliminary evidence of construct validity for the NHS following hip fracture surgery. Methods: This was a prospective observational study with cross-sectional validation analyses based on a single postoperative PROM assessment. Paired NHS–OHS and NHS–EQ-5D-5L data were available for 80 participants. The mean age was 79.3 years (SD 10.8), and 46 (57.5%) of these participants were female. Assessment occurred at a mean of 3.47 months (SD 0.75; range 2–7 months) following fracture surgery. The NHS was assessed in relation to the OHS and EQ-5D-5L index and dimensions. Convergent validity was assessed using Pearson and Spearman correlations, with exploratory analyses of individual OHS items and EQ-5D-5L dimensions. Known-groups validity was examined across OHS quartiles, and multivariable linear regression was performed. Results: The mean NHS was 60.4 (SD 25.4). NHS demonstrated a moderate correlation with OHS (Pearson r = 0.657, 95% CI 0.511–0.766; p < 0.001) and with the EQ-5D-5L index (r = 0.541, 95% CI 0.365–0.680; p < 0.001). All 12 OHS items and all five EQ-5D-5L dimensions were significantly associated with NHS. The strongest OHS item associations were pain when rising from a chair, pain, work/housework interference, limping, and washing/bathing. Mobility showed the strongest EQ-5D-5L dimension association. NHSs increased across OHS quartiles (Kruskal–Wallis H = 35.77; p < 0.001). In multivariable analysis, OHS remained associated with NHS (β = 1.54, 95% CI 0.80–2.28; p < 0.001). Conclusions: The NHS demonstrated preliminary evidence of cross-sectional construct and known-groups validity following hip fracture surgery. The findings support the NHS as a potentially useful complementary global measure of perceived hip normality, but do not establish test–retest reliability, responsiveness, clinically meaningful change, or suitability for standalone clinical use.

Background: The Oxford Hip Score (OHS) is a widely used hip-specific patient-reported outcome measure (PROM) following primary total hip arthroplasty (THA). This measure is calculated from answers to a 12-item questionnaire and can provide indices that indicate clinically meaningful success, such as patient acceptable symptom state (PASS). There were three purposes of the present single-cohort retrospective study: first, to determine the threshold PASS; second, to determine the influence of patient characteristics (age, gender, and body mass index (BMI)) and preoperative OHS and other PROMs of patients (namely, EQ-5D-3L, EQ-VAS, and pain VAS) who did not achieve this threshold; and third, to establish whether failure to achieve the PASS could still be associated with meaningful clinical improvement. Methods: This single-centre retrospective cohort study was conducted over 10 years from January 2013 to December 2022, during which 3997 patients completed pre- and postoperative OHS. The mean age was 68.3 years (standard deviation 11.7), and there were 2375 (59.4%) females in the cohort. Patient satisfaction was used as the anchor to define the PASS. Results: An OHS at 12 months postoperative of ≥36 points was identified as the threshold PASS (area under the curve 88.5%, 95% confidence interval [CI] 87.0 to 90.1, p < 0.001). Overall, 3002 (75.1%) achieved the PASS at 12 months. Lower BMI (odds ratio [OR] 0.96, 95% CI 0.95 to 0.98, p < 0.001) and higher preoperative OHS (OR 1.05, 95% CI 1.03 to 1.06, p < 0.001), EQ-5D (OR 1.88, 95% CI 1.33 to 2.65, p < 0.001) and EQ-VAS (OR 1.02, 95% 1.01 to 1.02, p < 0.001) were independently associated with achieving the PASS at 12 months. A total of 995 patients (24.9%) did not achieve this threshold. Patients not achieving the PASS had clinically meaningful worse (p < 0.001) postoperative outcomes and improvement relative to baseline in OHS, EQ-5D and EQ-VAS when compared to those achieving a PASS. Patients achieving the PASS were more likely to be satisfied with their THA (OR 16.8, 95% CI 12.8 to 22.1, p < 0.001); however, patients not achieving the PASS still had significant (p < 0.001) improvements relative to baseline in their OHS (9.6, 95% CI 9.0 to 10.2), EQ-5D (0.254, 95% CI 0.229 to 0.278), EQ-VAS (1.4, 95% CI −0.3 to 3.1) and pain VAS (8.2, 95% CI 6.1 to 10.3) and were more likely to be satisfied (70.8%) than not (29.2%). Conclusions: An OHS of ≥36 at 12 months was defined as the PASS. In total, 995 patients (29.4%) did not achieve this threshold, and in this group, patients were more likely to be female and have a high BMI and low preoperative OHS, EQ-5D, EQ-VAS, and pain VAS. Despite not achieving the PASS, they reported meaningful clinical improvements in OHS, EQ-5D, and pain VAS, and were satisfied with their THA (70.8%).