加压空心钉式外固定架治疗股骨粗隆间骨折的生物力学分析

Biomechanical Evaluation of Pressured Hollow Nail-external Fixator for Intertrochanteric Hip Fractures

目的通过加压空心钉式外固定架和普通外固定支架两种固定方式治疗老年股骨粗隆间骨折,行生物力学实验分析,评价两者固定的生物力学效果,为临床提供理论依据。方法采集8具新鲜人体股骨标本,进行贴片模拟临床生物力学试验,比较两者的生物力学特性。结果加压空心钉式外固定架与普通外固定支架相比,在抗压、抗弯和抗扭等生物力学性能上具有优势。抗压强度提高14%～17%、刚度提高17%～18%,抗扭转强度提高了27%,扭转刚度增大25%,失效载荷提高16%。结论应用加压空心钉式外固定架治疗老年股骨粗隆间骨折安全、有效,生物力学性能优越,固定可靠,尤其对于老年股骨粗隆间骨折的治疗是十分理想的选择。

Objective To evaluate biomechanical performance of pressured hollow nail - external fixator and ordinary external fixator via biomechanical test on embalmed femurs of human cadavers. Methods Eight matched pairs of embalmed femur of the aged cadavers which have similar bone mineral density scanned by DEXA were select. The fracture model was created through the intertroehanteric ridge by hand - saw and was fixed with pressured hollow nail - external fixator （ experimental group, group A） or ordinary external fixator （ con- trol group, group B）. The biomechanical test to simulate clinical application was manipulated to contrast biomeehanical performance of both sides. Results The fracture model fixed with pressured hollow nail - external fixator was predominant over ordinary external fixator in biomechanical performance. Pressured hollow nail - external fixator provide adequate anti - bending stiffness stability and satisfactory anti - torsion biomechanical properties. Conclusion Our biomechanical data indicated that pressured hollow nail - external fixator could be used as an effective method to treat intertrochanteric hip fractures of aged patients.