Rationale: the natural history and risk factors for hip osteoarthritis are still unknown.
Objective: to identify factors predicting a need for total hip replacement at some time during the course of hip osteoarthritis.
Patients and methods: outpatients evaluated between 1981 and 1986 for hip osteoarthritis were studied retrospectively. The date of diagnosis and the characteristics of the patients and hip disease at diagnosis were recorded. The risk of eventual total hip replacement was estimated using the Kaplan-Meier method. Uni- and multivariate Cox proportional hazard models were used to determine the value of each variable for predicting total hip replacement.
Results: we included 149 patients (50 males). The risk of total hip replacement was estimated at 36 +/- 4% five years after diagnosis. Factors with significant effects in the multivariate analysis were age older than 54 years at diagnosis (relative risk 3.15), body mass index greater than 27 (relative risk 2.97), and severe radiological joint space narrowing at diagnosis (relative risk 2.26).
Conclusion: this study confirmed the often severe course of hip osteoarthritis and identified several factors possibly associated with rapid progression.