summary Femoral shaft stress fractures are overuse injuries in which abnormal stresses are placed on trabecular bone of the femoral shaft resulting in microfractures. Diagnosis can often be made on radiographs alone but MRI studies should be obtained in patients with normal radiographs with a high degree of suspicion for stress fracture. Treatment is nonoperative with protected weightbearing in young patients with good bone quality. Prophylactic intramedullary nailing is recommended in patients > 60 or those with osteopenia. Epidemiology Demographics common in young athletic individuals Risk factors metabolic bone disorder long-term bisphosphonate use may be associated with osteopenia or osteoporosis in endurance athletes Etiology Mechanism occurs through crack propagation in bone repetitive loads that exceed the threshold of intrinsic bone healing repetitive stress on normal bone is a fatigue fracture repetitive stress on abnormal bone is an insufficiency fracture Presentation Symptoms often a history of overuse insidious onset of pain pain during activity is localized to the involved bone pain improves with rest Physical exam focal tenderness and swelling three point fulcrum test elicits pain examiner's arm is used as a fulcrum under the patient's thigh as gentle pressure is applied to the dorsum of the knee with the opposite hand test is positive if pain and apprehension is experienced at the point of the fulcrum Imaging Radiographs recommended views AP and lateral findings linear cortical radiolucency periosteal reaction endosteal and cortical thickening CT findings cortical lucency benign-appearing periosteal reaction MRI most sensitive and replacing bone scan for diagnosis views T2-weighted images login to view 3 more bullets T1-weighted images login to view 1 more bullet Technetium Tc 99m bone scan findings focal uptake in cortical and/or trabecular bone Treatment Nonoperative rest, activity modification, protected weight bearing indications login to view 1 more bullet technique login to view 2 more bullets Operative locked intramedullary reconstruction nail indications login to view 4 more bullets technique login to view 1 more bullet Prognosis Progression to complete fractures occurs if unrecognized