Conservative Treatment With Teriparatide for Symptomatic Incomplete Atypical Femoral Fractures: A Retrospective Observational Study

Introduction Prophylactic surgery for symptomatic incomplete atypical femoral fractures (SIAFFs) has demonstrated favorable outcomes. However, concerns remain regarding surgical intervention for a fracture that has not yet completed. This retrospective study aimed to evaluate the efficacy of conservative treatment using teriparatide (TPTD) as a conservative treatment for SIAFF. Methods This retrospective study reviewed 30 cases with SIAFF who underwent conservative treatment between November 2012 and September 2019. The diagnosis of SIAFF was based on the criteria established by the Task Force of the American Society for Bone and Mineral Research(ASBMR). The treatment protocol included (1) discontinuation of bisphosphonates, (2) use of 2 crutches or a four-point walker, (3) daily subcutaneous TPTD injection until pain subsided, and (4) monthly radiographic follow-up. Radiographs and bone scans were used to assess bone union, and follow-up continued for up to 2 years from protocol initiation. Comparisons between the successful and failed treatment groups were performed using the Student’s t-test for continuous variables and Fisher’s exact test for categorical variables. Results The mean age was 72.6 years (range, 55-87) and all patients were female. 13 cases involved the diaphyseal region and 17 involved the subtrochanteric region. The average duration of TPTD treatment was 6.5 months (range, 3-12), and the average follow-up was 45.5 months (range, 19-84) after the final injection. The mean SIAFF severity score was 9.5 (range, 7-11). Symptom-free bone union was achieved in 23 of 30 cases (76.7%). Five cases (4 with worsening pain, 1 with radiographic progression) underwent prophylactic intramedullary nailing, and 2 cases progressed to complete fracture and were treated with intramedullary nailing. Conclusion The result of this study suggests that the conservative treatment with teriparatide injection may be a potentially effective option for patients with SIAFF.