Physical activity before and after primary total hip arthroplasty: a registry-based study.

OBJECTIVE: Detailed assessment of activity before and after total hip arthroplasty (THA) including a long-term followup period is lacking. Our objectives were to evaluate patient activity levels prior to disease onset, prior to THA, and at 5 and 10 years after surgery, and to determine the predictors of high activity 5 years after surgery. METHODS: We included elective primary THAs performed between 1996 and 2012. A cross-sectional analysis compared mean University of California, Los Angeles (UCLA) activity scores over 4 periods: prior to symptom onset of osteoarthritis, prior to surgery, 5 years after surgery, and 10 years after surgery. Analyses of activity levels were performed and stratified by sex, age, body mass index (BMI), American Society of Anesthesiology (ASA) classes, and preoperative activity level. A prospective study was conducted to identify baseline characteristics associated with a high activity level (UCLA score ≥7) 5 years after surgery using logistic regression. RESULTS: The mean UCLA activity scores prior to symptom onset (n = 189), prior to THA (n = 203), 5 years after surgery (n = 1,085), and 10 years after surgery (n = 757) were 6.9, 3.5, 5.7, and 5.5, respectively. Postoperative scores were close to values prior to symptom onset in patients ages ≥55 years, but were lower in those who were younger. High activity was reported by 49% of patients prior to symptom onset, 5% of patients prior to surgery, and 28% of patients at both 5 and 10 years after surgery. The predictors of high activity at 5 years were younger age, male sex, a lower BMI, a lower ASA score, and an active lifestyle prior to surgery. CONCLUSION: Five and 10 years after primary THA, physical activity levels were substantially higher in men and women and in all age categories as compared to before surgery.