Osteomyelitis of the acetabulum is a rare condition accounting for only 12% of pelvic osteomyelitis cases. This report describes a previously healthy 10-year-old girl with subacute acetabular osteomyelitis and subsequent development of secondary septic arthritis of the hip. The patient presented with 3 weeks of groin pain, elevated erythrocyte sedimentation rate and C-reactive protein, synovial thickening of the hip on ultrasonography and diffuse signal uptake in the acetabulum on magnetic resonance imaging. Despite antibiotic therapy, her symptoms worsened clinically, and repeat Magnetic resonance imaging images showed worsening of the osteomyelitis with likely extension through the acetabulum and into the joint. A hip aspirate was positive for Fusobacterium, an atypical anaerobe. Hip arthroscopy, with identification of the site of extrusion and then extensive débridement and irrigation, was successful in helping to control and ultimately eradicate the infection. The patient regained normal hip function and returned to full activities. This case demonstrates how hip arthroscopy can serve as an important surgical treatment modality for acetabular osteomyelitis with intraarticular extension in addition to septic arthritis of the hip.
Scientist, CHEO Research Institute