Teriparatide Does not Have Beneficial Effects on Bone Healing in Complete Atypical Femur Fractures

Teriparatide is an anabolic drug sometimes administered to patients who have atypical femoral fracture (AFF). However, whether teriparatide has beneficial effects on bone healing remains uncertain. The present study aimed to analyze the association between teriparatide and bone healing in complete AFF. A total of 59 consecutive cases (58 patients) who underwent intramedullary nailing for complete AFF were categorized based on postoperative use of teriparatide into the non-teriparatide (non-TPTD, n = 34) and teriparatide groups (TPTD, n = 25). Time-to-bone union was evaluated and compared between the two groups. Additionally, multiple regression analysis was performed to evaluate factors affecting time-to-bone union. All participants were women, with a mean age of 77.6 years (range: 62-92). No significant difference in time-to-bone union was found between the non-TPTD and TPTD groups (5.5 months vs. 5.8 months, p = 0.359). Two patients in the non-TPTD group underwent reoperation (p = 0.503) due to failure caused by inadequate fixation, and both achieved bone healing after additional fixation with blocking screws. Multiple regression analysis revealed that the anterior gap of the fracture site postoperatively was a factor affecting time-to-bone union (p = 0.014). The beneficial effect of teriparatide on bone healing in complete AFF could not be confirmed. Additional randomized controlled trials are required. Nonetheless, appropriate techniques, including efforts to reduce the gap on the tensile side during the surgery, are important for reliable bone healing.