Outcomes of Atypical Femur Fractures in Geriatric Patients Treated with Anabolic Osteoporotic Medications

Abstract

Research Question: In geriatric patients with osteoporosis experiencing an atypical femur fracture (associated with long-term use of anti-resorptive therapy), will standardized treatment including treatment with an intramedullary nail and a post-operative regimen of parathyroid hormone (PTH) analogs allow for fracture healing and improved bone density over time?

Background: Our retrospective study evaluated fracture healing and bone density after an atypical femur fracture in geriatric patients treated with a protocol of intramedullary nailing and a change of osteoporosis therapy to an anabolic osteoporosis medication (PTH analogs). Specifically, these medications included Forteo® (teriparatide) and Tymlos® (abaloparatide). The aim of our study is to use the large patient population suffering from osteoporosis who were followed up at a busy osteoporosis clinic, The Center for Osteoporosis and Bone Health (BHC) in Fort Worth and analyze outcomes of fracture healing and bone density to determine the efficacy of such medications. Currently, treatment with such medications for fracture healing is limited due to cost-effectiveness and lack of clear evidence. Conclusive evidence through a large study would provide further direction and treatment options for patients and physicians seeking nonsurgical and less invasive treatment options.

Materials and Methods: We retrospectively initially reviewed records of 133 patients with a femur fracture treated in the Texas Health Fort Worth (THFW) fracture database with an intramedullary nail from 2017 to 2021 and followed up at the BHC for osteoporosis. Records and radiographs were evaluated to determine atypical femur fractures (AFFs). Nine patients had AFFs and met criteria (mean age 77.1 years). Of the 9 patients studied, 9 were female. All nine patients used oral bisphosphonate therapy before femur fracture, and all were prescribed a course of PTH analog therapy after surgical treatment with a femoral nail.

Results: The mean duration of follow up was 52 months. Patients were on anti-resorptive medications for an average duration of 9.4 years leading up to fracture (range, 3 to 18 years). Time to fracture-healing averaged 9 months (one patient [11%] underwent revision nailing prior to union) with all patients having a healed fracture during the course of PTH analog therapy for an average of 17.6 months (range, 8-24 months). The average T-scores improved over the course of treatment from an initial value of -0.986 to a repeat of -0.157. None had subsequent fractures.

Conclusion: In our study of 9 osteoporotic patients with AFFs, all fractures healed while on PTH analog therapy, T-scores improved, and no patients had subsequent fragility fractures on follow-up. This suggests that the implementation of a fracture-liaison service initiating PTH analog therapy plays an important role in fracture healing, combating delayed healing and non-union, improving bone density, and decreasing chance of subsequent fractures in osteoporotic patients.