Clinical Utility and Safety of Bone Cement Augmentation in Intramedullary Nailing for Proximal Femur Fractures: A Multicenter Prospective Observational Study

Introduction Proximal femur fractures are common in older adults and are associated with high morbidity and mortality. Bone cement augmentation during intramedullary nailing has been reported to improve implant stability; however, its clinical utility and safety in Japan remain unclear. Materials and Methods This multicenter prospective observational study included patients aged ≥45 years who underwent intramedullary nailing for trochanteric or basicervical femoral fractures between May 1, 2021, and July 31, 2023. Cement augmentation was applied exclusively to patients aged ≥60 years. Femoral neck fractures were excluded. Patients were treated with cement augmentation (CA group) or without augmentation (N group). The primary outcome was screw cut-out within 6 months postoperatively. Secondary outcomes included sliding distance (>5 mm), reoperation, nonunion, postoperative infection, and other complications. Group comparisons were performed using two-sided statistical tests with p < 0.05 considered significant. Results A total of 300 patients were analyzed (CA, n=97; N, n=203; mean age 86.8 years). No cut-out occurred in the CA group, whereas four cases (1.9%) occurred in the N group (p = 0.12). Sliding distance >5 mm was observed in 2 patients (2.0%) in the CA group and 12 patients (5.9%) in the N group (p = 0.108). Postoperative complications occurred in 2 patients (2.1%) in the CA group and 12 patients (5.9%) in the N group (p = 0.12). No cement-related adverse events were observed. Conclusions Cement augmentation during intramedullary nailing was safe and showed numerically lower rates of cut-out and excessive sliding compared with non-augmented fixation. Although statistical significance was not reached, these findings suggest a potential clinical role in elderly patients at high risk of fixation failure. Randomized controlled trials are warranted.