The efficacy, accuracy and complications of corticosteroid injections of the knee joint.

PURPOSE: Corticosteroid knee injections are being increasingly used in the conservative management of knee osteoarthritis. The procedure is usually performed in secondary care by orthopaedic surgeons and rheumatologists, but as the role of general practitioners in chronic disease management expands, joint injections are now frequently being performed in primary care. It is commonly perceived amongst clinicians that the benefits of corticosteroid knee joint injections in treating symptomatic knee osteoarthritis significantly outweigh the risks of complications. METHODS: The evidence in the literature for the benefits, accuracy, safety and complications of corticosteroid knee injections in osteoarthritis is reviewed. The perception that serious complications are rare is addressed, and the incidence of infectious complications is estimated. RESULTS AND CONCLUSIONS: Short-term symptomatic relief is the only evidence-based benefit of corticosteroid injection of an osteoarthritic knee. Accurate intra-articular placement is not achieved in up to 20% of injections and varies considerably with the anatomical approach used. There is no evidence that a medial approach is more accurate. The incidence of serious infectious complications following knee joint injections ranges widely, and may be as high as 1 in 3,000 and potentially far higher in high-risk patients for whom specialist management is advised.