To compare the efficacy of arthroscopic lavage plus administration of corticosteroids (ALC), arthroscopic lavage plus administration of placebo (ALP), and joint aspiration plus administration of corticosteroids (JAC) in knee arthritis, and to evaluate whether clinical or histologic characteristics determine outcome.
Patients with knee arthritis (not due to gout, osteoarthritis, or septic arthritis) were randomized over 3 treatment arms: ALC, ALP, and JAC. The primary end point was event-free survival, with events defined as 1) recurrence or persistence of symptomatic knee swelling necessitating local re-treatment, or 2) nonimprovement of the knee joint score. Synovial tissue specimens were collected and analyzed histologically to identify predictive factors of responsiveness.
A total of 78 patients were enrolled; 3 patients did not receive their allocated therapy and 3 were lost to followup. The median time until recurrence was 9.6 months after ALC, 3.0 months after JAC, and 1.0 month after ALP, corresponding to a relative risk (RR) of arthritis recurrence of 2.2 for JAC (95% confidence interval [95% CI] 1.2–4.2, P = 0.02) and 4.7 for ALP (95% CI 2.3–9.4, P < 0.0001) compared with ALC. A high versus low synovial extent of fibrosis conferred an RR for recurrence of 5.7 (95% CI 1.6–20.5, P < 0.01) after ALC.
Arthroscopic lavage plus administration of corticosteroids was more effective than arthroscopic lavage plus administration of placebo or joint aspiration plus injection of corticosteroids. The absence of fibrosis was a histologic predictor of a beneficial response.