Effect of Teriparatide on Fracture Healing in Patients With Incomplete Atypical Femur Fractures

Inclusion Criteria: i. Female or male; ii. Over the age of 30; iii. Experienced an incomplete AFF that satisfies the diagnostic criteria as set forth by the American Society for Bone and Mineral Research (ASBMR) International Task Force on AFFs: 1. Atraumatic or low trauma incomplete stress fractures, defined as fractures sustained with minimal force, such as a fall from standing height; 2. From distal to the lesser trochanter to proximal to the supracondylar flare along the femoral shaft. 3. Radiographic confirmation of AFF features is required for a definitive diagnosis. Incomplete AFF features include cortical thickening, cortical beaking, and lucency line. Patients with cortical beaking without lucency line can be included. Exclusion Criteria: i. Peri-prosthetic fractures, ii. High trauma fractures, iii. Pathological fractures secondary to metastases or metabolic bone diseases other than osteoporosis, iv. Fractures that are not confirmed by radiological investigations, v. Contraindication to use of teriparatide such as: 1. pregnant or nursing mothers, or women who are planning on pregnancy within 1 year of completing teriparatide therapy, 2. hypersensitivity to teriparatide, 3. severe renal impairment, 4. multiple myeloma, 5. active cancer in past 5 years (other than non-melanoma skin cancer), 6. primary hyperparathyroidism, 7. hypercalcemia, 8. Paget's disease or other conditions that may increase the risk for osteosarcoma, 9. Prior radiation therapy involving the skeleton, vi. Concomitant use of other osteoporosis therapies including bisphosphonates or denosumab (except calcitonin). AFF patients with complete fractures on the contralateral side or patients with secondary osteoporosis will not be excluded.