Case of the Month

24 year old elite triathlete with atypical groin and lateral thigh pain. External xrays and ultrasounds unremarkable.

Discussion

Medial compression stress fracture of the femoral neck.

Stress fractures of the femoral neck most frequently appear in two patient populations.

1. The young adult, in whom stress fractures result from overuse and repeated stress to normal bone (e.g. elite athletes/runners and military recruits). In the young athlete the fracture is typically a compression-type fracture in the inferomedial femoral neck.
2. Older patients with osteoporosis (especially women), in whom the fractures are more appropriately termed "insufficiency fractures" and may occur with normal activity or a seemingly insignificant increase in activity.

Patients usually present with groin pain aggravated by weight bearing.

Radiographic findings are often normal, and symptoms can be subtle.

MRI is exquisitely sensitive in detecting both marrow oedema, cortical thickening and a subtle fracture line.

A careful history and high index of suspicion are necessary to avoid missing the injury.