Intra-articular corticosteroids are effective in osteoarthritis but there are no clinical predictors of response.

OBJECTIVES To show whether intra-articular steroid injections are effective in osteoarthritis; to determine factors that predict response; and to determine whether injection has a beneficial effect on muscle strength. METHODS Double blind, placebo controlled, crossover study in 59 patients with symptomatic osteoarthritis of the knee. Outcome measure-Primary outcome measure: change in visual analogue score for pain at three weeks. Predictors of response analysed using logistic regression with a 15% decrease in pain score at three weeks defining response. RESULTS Intra-articular methyl prednisolone acetate produced a significant reduction in visual analogue pain score at three weeks compared to both baseline (median change -2.0 mm, interquartile range -16.25 to 4.0) and placebo (median 0.0 mm, interquartile range -9.0 to 6.25). No clinical predictors of response could be identified. Muscle strength was not significantly improved in the short term by intra-articular injection. CONCLUSIONS Intra-articular corticosteroids are effective for short term relief of pain in osteoarthritis but predicting responders is not possible. There may be a place for their more widespread use.