Stress fractures are most commonly seen in the lower extremity including the femur, tibia, and feet. They are frequently prevalent in athletes, the elderly, diabetics with neuropathy, and individuals with hip abnormalities. A stress fracture occurs from repetitive stress that exceeds the body’s ability to heal and remodel and is considered a fatigue failure of the bone. The fracture starts as a microscopic fracture, and if not healed, progresses to a macroscopic fracture that can be visible on xrays. In the hips they occur most commonly in the femoral neck in two types; tension or compressive stress fracture. A tension stress fracture occurs on the top of the femoral neck and frequently does not heal on its on with non-weight bearing but requires surgical fixation. A compression stress fracture occurs on the undersurface of the femoral neck and can heal with simple observation, activity modification and a period of non-weight bearing.
Stress fractures can present as a gradual pain or a sudden pain after a recent history of increased activity level. Swelling can also be present that is focused in the area of injury. The pain is worsened when standing or during physical activity that stresses the bone. Patients frequently limp, but are usually able to put some weight through their affected leg that may worsen the pain.
Diagnosis is made by history of pain and swelling of the hip without a known specific trauma or after a recent increased activity level. Pain and swelling are usually focused to the area of the injury. X-rays are often normal in the first two to three weeks when the fracture is on a microscopic scale, but as the fracture progresses, the fracture line may or may not be visible on xray. An MRI scan can be helpful if the diagnosis is unclear, and can show edema and swelling in the suspected area as well as the surrounding soft tissue. Physical examination is usually the first point of contact.
Fractures are typically caused by an accident or traumatic event, and are not always preventable. Stress fractures, however, are from overuse injuries and a sudden increase in activity. These injuries can be prevented by stopping the aggravating/overuse activity and to rest.