Incidental Unilateral Lateral Cortical Hypertrophy of the Proximal Femur Following Low-Energy Trauma Without Prior Bisphosphonate Exposure: A Case Report.

Prolonged treatment with bisphosphonates has commonly been associated with atypical femur fractures. Localized periosteal thickening of the femoral lateral cortex is considered one of the minor features of these fractures and is caused by distribution of tensile stress and the inhibition of bone resorption. Other medications also potentially influence bone metabolism by inhibiting bone resorption. Here, we present a 60-year-old female with unilateral lateral cortical hypertrophy of the proximal femur with no history of bisphosphonate therapy. Long-term administration of proton pump inhibitors may contribute to cortical hypertrophy in patients with low-bone-turnover osteoporosis attributable to deficiencies in vitamins D and K. Two years after the patient's initial visit to our hospital, radiographs demonstrated a reduction in periosteal thickening along the lateral cortex of the proximal femoral diaphysis. In a bisphosphonate-naive patient with lateral cortical hypertrophy of the proximal femur, proton pump inhibitors' use may represent a contributing factor that warrants consideration due to its potential association with disturbances in bone metabolism.