Effectiveness of Adapted Physical Activity on Quality of Life of Patients with Knee and Hip Replacement: A Randomized Pilot Study

Background: Total hip (THR) and knee replacement (TKR) effectively treat end-stage osteoarthritis, but many patients continue to experience functional limitations and reduced quality of life (QoL) after rehabilitation. The aim of this pilot study was to assess the changes in terms of QoL in people with THR and TKR after a specifically designed PA intervention. The secondary aim was to evaluate changes in physical function through strength and mobility tests. Methods: Eighteen participants (mean age 65.8 ± 7.1 years) were enrolled at the Rizzoli Orthopedic Institute and were randomly assigned to an intervention group (IG), which completed a six-month supervised PA program (6 months after surgery), or a control group (CG), which received standard care. Assessments were conducted at four time points: before surgery, after rehabilitation, and at 9- and 12-month post-surgery. Repeated measures ANOVA was used to assess within- and between-group differences over time, with post hoc pairwise comparisons conducted using independent t-tests with Sidak correction. The level of statistical significance was set at p < 0.05 for all analyses. Results: Both groups showed significant improvements in QoL over time, with greater gains in physical functioning observed in the IG. Lower limb strength increased more in the IG; however, the differences between groups were not statistically significant. The Timed Up and Go and 30-Second Chair Stand Test improved in both groups. No adverse events were reported. Conclusions: These findings support the feasibility and potential benefits of adapted PA programs after rehabilitation. Although no significant differences emerged between groups, clinically relevant improvements were observed in the IG. Larger studies are warranted to confirm these results and explore long-term outcomes across multiple domains.