Improvement in six of the 12 Oxford Knee Score questions is independently associated with patient satisfaction following knee arthroplasty.

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.