Acute osteomyelitis of the acetabulum induced by Staphylococcus capitis in a young athlete.

Acute hematogenous osteomyelitis (AHOM) of the acetabulum is a rare condition in children and usually caused by Staphylococcus aureus. We present an 11-year-old soccer athlete who suffered from acute osteomyelitis involving the acetabulum caused by S. capitis, a normal flora of the human skin but never reported in this condition. The disease was associated with repetitive skin injuries of the knee and potential osseous microtrauma of the hip joint by frequent rigorous exercise. This unusual case suggests that osseous microtrauma of the acetabulum, in addition to repetitive skin injuries, allowed normal skin flora to colonize to the ipsilateral acetabulum, which served as a favorable niche and subsequently led to AHOM.