Femoral diaphyseal fatigue stress fracture in an older adult male with normal bone mineral density.

A healthy man in his early 70s taking no regular medications presented to a tertiary hospital emergency department three times in 4 weeks with the isolated symptom of moderate-to-severe non-traumatic unilateral distal right thigh pain on weightbearing. Plain radiographs of the femur and knee were performed on each occasion. Imaging reports of the first and second occasions made a comment of mild degenerative changes of the tibiofemoral joint with no other abnormalities, resulting in the patient being discharged with a diagnosis of knee osteoarthritis, provision of analgesia and advice to follow-up with his general practitioner. The third imaging report highlighted a subacute transverse diaphyseal femoral fracture that was subsequently confirmed using CT. Further investigations ruled out underlying pathological causes of the atraumatic fracture, and the fracture was managed conservatively. This case explores a femoral diaphyseal fatigue stress fracture in a patient with no intrinsic risk factors.