Predictive Factors of Pain and Functional Outcome 5 Years Following Total Hip Arthroplasty: A Prospective Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement Cohort Study.

BACKGROUND

Previous reports have identified a number of potential predictors of pain and function after total hip arthroplasty (THA). However, the results of these studies were conflicting, and most had a short follow-up after THA. The purpose of this study was to identify factors predictive of pain and function 5 years after THA.

METHODS

A multicenter cohort of 7,934 primary unilateral THA patients was prospectively enrolled in the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement consortium. Demographic data, comorbidities, and patient-reported outcome measures were collected preoperatively and postoperatively at 5 years, including the Hip Disability and OSteoarthritis Outcome Score (HOOS) pain and activities of daily living (ADL) scores. Multivariate logistic regression models with 95% confidence interval were used to identify independent predictors of pain and function at 5 years.

RESULTS

The patient dissatisfaction percentage was 8.2% at 5 years after THA. The multivariate regression identified the following predictive factors for the HOOS pain score at 5 years: age, educational level, insurance, smoking, race, Charlson Comorbidity Index, back pain severity, number of other lower extremity painful joints, the Knee Injury and Osteoarthritis Outcome Score pain severity of the ipsilateral knee, preoperative Short-Form Health Survey 36-item (SF-36) mental component summary score, and HOOS pain scores. The multivariate regression identified the following predictor factors for HOOS ADL score at 5 years: body mass index, insurance, smoking, race, back pain severity, number of other lower extremity painful joints, Knee Injury and Osteoarthritis Outcome Score pain severity of ipsilateral knee, preop HOOS ADL, and preoperative SF-36 mental component summary score and SF-36 physical component summary score.

CONCLUSIONS

Overall, 8.2% of patients were dissatisfied 5 years after primary THA. We have identified a number of factors that predict less improvement in pain and function 5 years after THA. These potentially modifiable factors can be targeted with preoperative patient optimization programs to improve patient outcomes and satisfaction after primary THA. Knowledge of these factors that predict less improvement in pain and function can assist the surgeon and patient during shared decision-making, and in setting appropriate patient expectations preoperatively.