Changes in daily physical activity before and after total hip arthroplasty. A pilot study using accelerometry

The present single-centre prospective follow-up study assessed the objective changes in physical activity undertaken before and after total hip arthroplasty (THA) using accelerometry. We enrolled 12 female patients who underwent home-based accelerometry assessment one month before and six months after the THA procedure. We assessed the daily amount of physical activity and energy expenditure related to physical activities. We also recorded the intensity of the physical activity, and pre- and post-operative clinical evaluation with the Harris Hip Score (HHS). At 6 months after surgery, we found a statistically significant increase of the total energy cost of physical activity (DA) (P=0.02), without significant increase of activity time (P>0.05). The energy cost of moderate/vigorous activity was statistically significant increased after surgery (P=0.008). Finally, HHS improved form 53.9±15.3 pre-operatively to 78.1±12.2 post-operatively (P=0.03). In our patients, the improvement was significant only for the total energy cost of daily activity. Thus, although patients did not exhibit a more active lifestyle, as shown by the slight increase of the activity time, they significantly increased the amount of moderate or vigorous activities performed after surgery.