Little is known about the long-term changes in physical activity (PA) after total hip arthroplasty (THA). The purpose of this study is to describe the changes in the number of steps and intensity of PA as measured by accelerometers, patient-reported physical function, and health-related quality of life of THA patient preoperatively and at 1 and 3 years after THA.
This study included 153 patients (mean age, 61.4 years; 86.3% women) who wore an accelerometer for 10 consecutive days and completed the Oxford Hip Score (OHS) and the Short Form 8 at the 5-year follow-up after THA. PA was evaluated based on the mean steps per day and the time spent performing moderate-to-vigorous PA (MVPA) per week.
All 5 indicators had significantly increased at 1 year after THA, although only MVPA and OHS had further increased significantly at the 3-year follow-up. The predictor of improvement in the number of steps from baseline to 1 year post-THA was younger age, while those of improvement in MVPA from baseline to 3-year post-THA were younger age, higher OHS, and better Short Form 8 mental component scores using mixed-model analysis. Participation in the PA measurements was high (69.9%) at the 3-year follow-up. No significant changes were observed for these outcomes in the remaining cohort beyond 3 years after THA.
In post-THA patients, MVPA continued to increase for 3 years postoperatively. Therefore, PA must be measured over the medium term to long term following THA.