Anaerobic osteomyelitis of femoral head with intraosseous, intra-articular, bursal and muscle pneumatosis.

A case is presented of anaerobic osteomyelitis with intraosseous pneumatosis resulting in extension of gas in soft tissue structures and femur in a patient with mitral valve vegetation and bacteremia. The finding of intraosseous pneumatosis and its extension into the hip joint, iliopsoas bursa and subgluteus medius bursa is depicted. Intraosseous pneumatosis is a rare but concerning finding for osteomyelitis in the absence of a penetrating wound, recent surgery, biopsy or fracture.