Mycobacterium abscessus (M. chelonei) infection of the knee joint: report of two cases following intra-articular injection of corticosteroids.

In 2 patients (3 knees) acute infectious arthritis of the knee developed following intra-articular injection of corticosteroids. The pathogenic organism responsible for the infection was found to be Mycobacterium Abscessus (M. Chelonei). Diagnostic difficulties were encountered due to the rarity of such infections and elusive identification of the organism with routine laboratory procedures. Therapeutic approaches necessitated combined radical surgical procedures together with antituberculosis drugs. Surgical treatment also afforded correct and definitive identification of the organism, from material obtained at operation. Although these mycobacteriae were found to be resistent to antituberculosis drugs, these same drugs proved effective clinically.