Lateral insufficiency fractures of the femur caused by osteopenia and varus angulation: a complication of total hip arthroplasty.

Lateral femoral insufficiency fractures in total hip arthroplasty occur due to osteopenia and varus positioning of the femoral component, the femur itself, or both. The presentation of these fractures can be unclear but usually involves the insidious onset of unexplained thigh or groin pain. The patients are likely to have significant comorbidities as well. Characteristic radiographic findings may be present, depending on when the patient presents. The insufficiency fractures generally occur at the level of the femoral stem tip on the lateral cortex of the femur. If left untreated, pain and loss of function continue. Eventually an insufficiency fracture can progress to a displaced periprosthetic fracture. Nonsurgical treatment is not successful. Recommended treatment involves revision to a long-stem femoral component. The risk of postoperative complications is significant.