Abstract
BACKGROUND: Young adults with comminuted femoral neck fractures face elevated risks of postoperative shortening and osteonecrosis of the femoral head (ONFH) This study evaluates a novel surgical protocol integrating the Femoral Neck System (FNS) and 3D-printed patient-specific Cannulated Compression Screw (CCS) navigation guides to address these challenges. METHODS: A retrospective analysis was conducted on 75 young adults with femoral neck fractures complicated by posteromedial wall comminution/defects treated between October 2022 and June 2024. Patients were stratified into three groups: CCS fixation, FNS fixation, and FNS + CCS fixation. For the FNS + CCS group, preoperative 3D CT data were reconstructed in Mimics 21.0 software to establish fracture models, simulate reductions, and design patient-specific CCS navigation guides. Outcome measures included operative time, number of intraoperative fluoroscopies, fracture healing time, full weight-bearing time, follow-up duration, Garden alignment index, Harris Hip Score (HHS), femoral neck shortening, reduction quality, and ONFH incidence. RESULTS: Significant differences in operative time were observed between FNS and CCS groups (P < 0.01), and between FNS + CCS and CCS groups (P < 0.05). The FNS group demonstrated shorter full weight-bearing time than the CCS group but longer than the FNS + CCS group (P < 0.05). The number of intraoperative fluoroscopies was significantly lower in the FNS group than in both the CCS and FNS + CCS groups (P < 0.05). The FNS + CCS group exhibited superior HHS compared to the CCS group (P < 0.01) and significantly reduced femoral neck shortening versus the FNS group (P < 0.05). ONFH incidence was markedly lower in the FNS + CCS group than in both monotherapy groups (P < 0.05). No intergroup differences were detected in healing time, follow-up duration, Garden index, or reduction quality. CONCLUSIONS: The FNS-CCS combined fixation with patient-specific navigation guides effectively minimizes postoperative femoral neck shortening, accelerates functional recovery, and reduces ONFH incidence in young adults with comminuted femoral neck fractures, establishing a stable and controllable therapeutic protocol.