Femoral neck stress fractures.
Femoral neck stress fractures are unusual but not rare athletic injuries. In one large series they accounted for 5% of all stress fractures. Early recognition of the signs and symptoms of this injury is important, as objective findings are often delayed. The potential problems from this fracture are serious. The aetiology includes repeated force above a certain load without internal bone response time. Loss of shock absorption due to muscle fatigue and limitation of ankle motion by boots or splints may also play a role. The diagnosis is based on the finding of groin pain and radiographic testing, which often requires plain films and bone scintigraphy. Regular radiographic findings present in stages progressing from a normal film through sclerosis to a disruption of the cortex and displacement. Bone scintigraphy may be positive 2 or more weeks before plain film changes are present. Classification schemes follow the radiographic changes. A classification system and treatment plan may be based on 3 categories of these fractures--compression side, tension side and displaced femoral neck fracture. Treatment ranges from rest with early symptoms to surgical stabilisation for any widening of cortical cracks and/or displaced fractures. Prompt diagnosis and carefully supervised treatment is the key to preventing displacement. Prolonged disability secondary to pain, nonunion or avascular necrosis is associated with displacement of the femoral neck stress fracture.