We carried out a 3 years, randomized, double-blind, placebo-controlled, multicenter clinical trial in patients with hip osteoarthritis in order to:

• evaluate the ability of diacerein, an interleukin-1β inhibitor, to slow the progressive decrease in joint space width observed in patients with hip osteoarthritis
• to investigate the potential structure-modifying effect of diacerein in patients with hip osteoarthritis

This study compare also after ten years the percentage of patients in each treatment group who require a hip replacement surgery

Inclusion Criteria:

• Outpatients fulfilling the American College of Rheumatology criteria for the diagnosis of hip osteoarthritis.
• Lequesne algofunctional index of at list 3 points.
• Radiographic criterion for inclusion: joint space width (JSW) between 1 mm and 3 mm. If the JSW exceeded 3 mm, it had to be at least 0.5 mm thinner than JSW of the contra lateral hip, measured at its narrowest point.

Exclusion Criteria:

• Intraarticular injection or arthroscopy of the hip during the three months prior to inclusion in the study.
• Any systemic or intraarticular corticosteroid as well as other potential symptom-modifying drugs for osteoarthritis were not allowed during the study.