Abstract
Hip dislocation is mostly caused by high-energy injury, and only rarely by athletic injury. Here we report a 17-year-old boy who suffered hip dislocation while sprinting. When he suddenly stopped after the sprint burst, posterior dislocation of the hip and anterior wall fracture of the acetabulum occurred. The hip is generally displaced posteriorly with the hip flexed, adducted, and internally rotated. Posterior wall fracture of the acetabulum sometimes occurs when the hip is less flexed. Although some authors have reported posterior dislocation with posterior wall fracture, there has been no previous report of posterior dislocation with anterior wall fracture. In the present case, the femoral neck might have impinged against the anterior acetabulum wall with the hip flexed, adducted, and internally rotated. In this position, an axial load would have been added to the hip joint, resulting in posterior dislocation and anterior wall fracture. We examined the hip joint by MRI in 5 months after the injury, and no osteonecrosis of the femoral head was evident. Careful follow-up will be necessary because hip dislocation often results in osteonecrosis even in cases of low-energy injury.
