Year of follow-up, patient age, and comorbidity are prognostic factors for sustained functional outcome after total hip replacement (THR). Functional results are somewhat constant from years 1 to 5 after surgery and then show gradual decline.
Gandhi and colleagues used longitudinal regression modeling to identify factors that predict sustained functional outcome for at least 1 year after THR. They analyzed data from 636 consecutive patients with osteoarthritis who received THR with the Western Ontario McMaster University Osteoarthritis Index (WOMAC), Medical Outcomes Study Short-form 36 (SF-36), SF-36 Physical Function (PF) score, and SF-36 Role Physical (RP) score.
The year of follow-up, older age, and greater comorbidity predicted less functional outcome on the WOMAC score. These factors plus male sex predicted a less sustained functional outcome on the SF-36 PF. Older age and comorbidity were independent predictors of a poorer outcome on the SF-36 RP. Overall, the year of follow-up, older age, and greater comorbidity consistently predicted a less enduring functional outcome after THR.
The authors noted that understanding of the factors that predict good functional outcome after THR can help surgeons better prepare patients and that patients with realistic expectations are more likely to be satisfied with their outcomes.
