Femoral subtrochanteric insufficiency fracture after long-term bisphosphonate therapy masked from foraminal stenosis of lumbar spine: A case report

We present a case of an insufficiency fracture of the subtrochanteric region of the femur in a 78-year-old woman masked by lumbar spinal foraminal stenosis. She complained of pain and a tingling sensation in the anterior and lateral side of the right thigh, leg, and ankle. Selective transforaminal epidural (L4-5, Rt.) and caudal block were done under the diagnosis of lumbar foraminal stenosis. The tingling sensation was completely relieved, but the pain was not completely relieved. The patient had been receiving bisphosphonate therapy for 6 years under the diagnosis of osteoporosis. We performed magnetic resonance imaging, which showed a unicortical break line and marrow edema around the hypertrophied area. Surgery was done. In cases with incomplete relief of the pain in the thigh following epidural block, physicians should keep in mind the possibility of femoral insufficiency fracture in patients who have received long-term bisphosphonate therapy.

Bilateral Femoral Subtrochanteric Insufficiency Fractures after Long-term Bisphosphonate Therapy / 대한정형외과학회잡지

Bisphosphonates are widely used for the treatment of osteoporosis to prevent fractures. Although their safety and efficacy have been well documented, some recent reports have drawn attention to a possible correlation between long term bisphosphonate therapy and the occurrence of insufficiency fractures owing to prolonged bone turnover suppression. A 71-year-old woman presented to our emergency room with pain and deformity of the left thigh with low energy injury. Radiographs showed a left femur subtrochanteric fracture and a transverse sclerotic fracture line in the right femur subtrochanteric area with cortical thickening, which indicate insufficiency fractures. She had been treated with sodium alendronate 70 mg per week for 6 years and was suffering from prodromal symptoms in both thighs from 3 months ago. After surgery and intraoperative bone biopsy for a left subtrochanteric fracture, her osteoporosis medication was changed with a bone forming agent. We have analyzed the characteristics of insufficiency fractures related to long term bisphosphonate therapy. Physicians should keep in mind the possibility of insufficiency fracture in cases such as ours, especially with prodromal thigh pain.