Physical activity after unicompartmental knee arthroplasty: Long‐term participation, activity volume and patient‐reported limitations

Abstract Purpose To characterize long‐term patient‐reported sports and physical activity after unicompartmental knee arthroplasty (UKA), including participation, weekly volume, perceived exertion, time to resumption, limitations, satisfaction and sex‐based differences. Methods This retrospective single‐institution study included 150 patients who underwent primary UKA between 2014 and 2022. An 11‐item electronic questionnaire administered in 2025 assessed activity at 5 years before UKA, 1 year before UKA, 1 year after UKA and at current follow‐up. Current participation was the primary outcome. Historical responses were treated as retrospectively recalled estimates. Mean follow‐up was 6.8 ± 2.4 years. Results Of 190 contactable patients, 150 responded (78.9%). Mean age was 65.1 ± 10.9 years. Participation was recalled by 33.3% at 5 years before UKA, 8.0% at 1 year before UKA and 25.3% at 1 year after UKA; 33.3% reported current participation. Among current participants, 74.0% reported >3 h/week and 48.0% reported moderate‐or‐higher exertion. Overall, 49.3% resumed activity within 12 months, 42.0% perceived improvement and mean satisfaction was 3.84 ± 1.30. Activity‐related limitations and long‐term restrictions were reported by 75.3% and 30.0%, respectively. Most outcomes were similar between women and men; the fully adjusted association between male sex and improved intensity was not significant (adjusted odds ratio 2.08, 95% confidence interval 0.90–4.80). Conclusions At long‐term follow‐up after UKA, one‐third of patients reported current sports or physical activity participation, and most current participants reported >3 h/week. However, only half resumed activity within 12 months, and residual limitations were common. Historical group‐level proportions should not be interpreted as individual return to activity or longitudinal recovery. Level of Evidence Level IV.