Bone stress injuries

Bone stress injuries are overuse injuries caused by repetitive mechanical loading that exceeds the capacity of the bone to repair, resulting in microdamage and potential fracture.

Microdamage from high physical demands on normal bone or normal physiological loads on compromised bone accumulates, weakening its structural integrity and leading to stress reactions or stress fractures.

The incidence of bone stress injuries of the ankle and foot in physically active young adults is estimated at 126 per 100,000 person-years. Stress fractures occur in up to 10% of military recruits during basic training.

Bone stress injuries are common in military recruits and high-level athletes, especially in track and field, volleyball, and gymnastics, as well as in individuals with female athlete triad. Low bone mineral density and sudden changes in load volume are also important risk factors. Other risk factors include pes cavus, leg length discrepancy, forefoot varus, low vitamin D intake, alcohol consumption, smoking, being underweight or overweight, low fitness level, and NSAID use.

Bone stress injuries present with localized bone pain, tenderness, edema, and loss of function. The most commonly involved regions are the lower leg (40%), foot (35%), and lumbar spine or pelvis (15%). High-risk sites include the anterior tibial shaft, femoral neck, great toe sesamoids, medial malleolus, patella, proximal second or fifth metatarsal, talus, and tarsal navicular. The fulcrum, hop, and heel percussion tests can help diagnose fractures of the femur, tibia, and ankle.