动力加压髋螺钉取出后钉道内植骨的生物力学意义

Biomechanical significance of bone grafting in the screw channel after taking out dynamic hip screws

目的 探讨动力加压髋螺钉 (DHS)内固定治疗股骨上段骨折愈合后 ,取出DHS以后不处理的股骨上段、钉道植骨的股骨上段和完整的股骨上段的生物力学特性 ,为临床DHS取出术后进一步治疗提供理论依据。方法 收集 16具新鲜尸体股骨标本进行实验应力分析 ,分别测定完整股骨上段、DHS取出后不处理的股骨上段和DHS取出后钉道内植骨股骨上段的力学特性。结果 DHS取出术后 ,不处理的股骨上段与完整股骨上段、DHS取出术后钉道植骨的股骨上段的力学特性相比 ,差异有显著性 (P <0 0 1)。结论 股骨颈骨折DHS治疗骨折愈合取出内固定后 ,应在股骨上段螺钉道内植骨补强 ,这有利于提高股骨上段的生物力学性能 ,便于患者早期全负荷功能锻炼 。

Objective Femoral neck fractures were treated with internal fixation of dynamic hip screws. After femoral neck fracture healing, the biomechanical changes of proximal femurs without dynamic hip screws, proximal femurs with bone grafting in the channel of screw were investigated after dynamic hip screws were taken out to provide theoretical basis for the further management of patients after the procedure. Methods The proximal femurs of 16 fresh cadavers were used in stress analysis. The biomechanical features of intact proximal femurs, proximal femurs without dynamic hip screw and proximal femurs with bone grafting in the channel of screw were determined after dynamic hip screws were taken out. Results The biomechanical features showed statistical difference ( P <0 01) among intact proximal femurs, proximal femurs without dynamic hip screw and proximal femurs with bone grafting in the channel of screw after dynamic hip screws were taken out. Conclusion For the treatment of proximal femur fractures with dynamic hip screws, bone grafting in the channel of screw should be used to improve biomechanical integrity after fracture healed and dynamic hip screws were taken out. This is of benefit to loading in early stage, preventing complications of pathological fractures, refracture and hip malformation,etc.