Mycobacterium kansasii arthritis of the knee joint.

Mycobacterium kansasii infection of the knee joint was diagnosed in an 11-year-old boy on the basis of skin testing to atypical mycobacteria, and a positive culture from a synovial tissur biopsy. Appropriate antituberculose drugs shoud be institute as sole treatment if no bony destruction is present. Ifthere is no response to chemtherapy, synovectomy should be performed.