骨密度对股骨颈骨折内固定效果影响的生物力学研究

目的:为提高股骨颈骨折内固定治疗的效果,通过生物力学实验,观察骨密度对内固定强度的影响。方法:取成人股骨上段防腐标本２０只,测量股骨颈骨密度值。根据骨密度值高低,将标本分为Ａ、Ｂ两组,每组１０只。两组的骨密度值有显著差异(Ｐ＜０．０１)。将标本制成股骨颈骨折模型,均用加压螺纹钉内固定后行负载实验,比较两组固定的强度。结果:骨密度低的Ｂ组标本在４００Ｎ载荷下的骨折位移明显大于骨密度高的Ａ组(Ｐ＜０．０１),且最大负荷也明显小于Ａ组(Ｐ＜０．０１)。结论:骨密度对股骨颈骨折固定的强度有直接影响,骨密度值可作为预测股骨颈骨折内固定治疗效果的一个重要指标。

Biomechanical study of the effect of bone density on the fixation strength of femoral neck fracture

Objective: To study biomechanical basis of the effect of the bone mineral density (BMD) on the fixation strength of femoral neck fracture. Methods: The BMDs of 20 embalmed proximal femoral specimens were measured. According to BMDs these specimens were divided into two groups named A and B ( n = 10). The BMDs of group B were significantly (P < 0.01) lower than that of group A.The models of femoral neck fracture were made on these specimens and then internal fixations were performed using a compression screw. Axial loadings were tested to compare the stability and strength of two groups. Results: Under a 400 N load, the displacements of the specimens in group B were significantly bigger than those in group A, and the maximum loads of group B were significantly smaller than those of group A. Conclusions: BMD was found to be correlated with the stability of femoral neck fracture and may be a useful predictor of internal fixation.