Objective. To evaluate the efficacy of joint lavage and intraarticular steroid injection, alone and in combination, in the treatment of patients with symptomatic knee osteoarthritis (OA).Methods. Ninety-eight patients with painful tibiofemoral OA were enrolled in a prospective, randomized, controlled, 2 ؋ 2 factorial-design trial of 6 months' duration. The 4 treatment groups consisted of 1) intraarticular placebo (1.5 ml of 0.9% normal saline), 2) intraarticular corticosteroids (3.75 mg of cortivazol in 1.5 ml), 3) joint lavage and intraarticular placebo, and 4) joint lavage and intraarticular corticosteroid. Outcome measures evaluated at baseline, week 1, week 4, week 12, and week 24 included severity of pain (100-mm visual analog scale [VAS]), global status (100-mm VAS), and Lequesne's functional index.Results. No interaction between steroid injection and joint lavage was demonstrated. Patients who had undergone joint lavage had significantly improved pain VAS scores at week 24 (P ؍ 0.020). In contrast, corticosteroid injection had no long-term effect (P ؍ 0.313); corticosteroid injection was associated with a decrease in pain only at week 1 (P ؍ 0.003) and week 4 (P ؍ 0.020). After week 4, Lequesne's functional index was not significantly improved regardless of the assigned treatment.Conclusion. Compared with placebo, both treatments significantly relieved pain but did not improve functional impairment. The effects of the 2 treatments were additive. Cortivazol provided short-term relief of pain (up to week 4). The effects of joint lavage persisted up to week 24.Osteoarthritis (OA) of the knee is one of the most common forms of arthritis and a major cause of pain and disability, particularly among the elderly (1). Intraarticular corticosteroid therapy is widely used in the treatment of OA, particularly for the knee. A recent survey of rheumatologists in the US suggested that Ͼ95% prescribe corticosteroids "at least sometimes," and 53% "frequently" (2). Such therapy is recommended in the American College of Rheumatology (ACR) guidelines for the medical management of knee OA (3), and its clinical benefit has been evaluated in several controlled studies (4-6). However, a recent systematic review of studies of intraarticular (IA) corticosteroid use in patients with knee OA (7) showed that these studies were flawed by numerous methodologic deficiencies. Two recent double-blind, placebo-controlled studies showed significantly greater decreases in pain with corticosteroid treatment than with placebo only at week 1 in 1 study and at week 3 in the other (8,9). Some authors concluded that the evidence for efficacy of IA corticosteroids in knee OA is relatively weak (10,11).The results of several studies have suggested that joint lavage, either alone or combined with arthroscopy,
