Predicting the longer-term outcomes of total hip replacement.

Abstract

The objective of this study was to identify the patient-level predictors (age, sex, body mass index, mental health, and comorbidity) for a sustained functional outcome at a minimum 1 year of followup after total hip replacement (THR). We reviewed data from our registry on 636 consecutive patients from 1998 to 2005. Demographic data and the outcome scores of the Western Ontario McMaster University Osteoarthritis Index (WOMAC) and Medical Outcomes Study Short-form 36 (SF-36) scores were extracted from the database. Longitudinal regression modeling was performed to identify the predictive factors of interest. Fourteen percent of patients were missing outcomes data at 1 year of followup. The mean followup in our cohort was 3.3 years (range 1-6 yrs) and there were no revisions for aseptic loosening performed during this time. Mean clinical outcome scores were found to be relatively constant for the 6 years after surgery. Older age, year of followup, and greater comorbidity were identified as negative prognostic factors for a sustained functional outcome following THR (p < 0.05). Understanding of longterm surgical outcomes should be appropriately used to set realistic patient expectations of surgery.