步态水平对髋关节假体周围骨重建的影响

Effects of Gait Level on Bone Remodeling around Hip Prosthesis after Hip Replacement

目的针对髋关节置换术后患者步态运动水平变化,研究假体周围骨密度(bone mineral density,BMD)变化率的变化趋势,揭示置换初期、长期运动变化对骨重建的影响规律。方法基于自适应骨重建理论,建立股骨-假体有限元模型,以术后初期、长期步态水平作为重建参数计算假体周围BMD分布,采用Gruen分区方法量化BMD的变化。结果术后初期,恒定步态组与变化步态组BMD存在明显差异,最大差异发生在低步态组中,造成大转子区域BMD减小41%;步态运动提高促进假体近端、中端BMD变化,显著影响发生在大转子区域,造成BMD增加47%;术后长期阶段,步态运动提高促进假体中端、末端区域BMD恢复,BMD增加2%~9%。结论研究结果为髋关节置换后患者康复过程提供指导。

Objective To investigate changes in gait level of patients after hip replacement,the variation trend of bone mineral density(BMD)around the prothesis was studied,so as to reveal the influence pattern of gait level at postoperative initial and long-term stages on bone reomodeling.Methods Based on adaptive bone remodeling theory,the finite element model of femer-prosthesis was developed.The BMD distribution was calculated using the initial and long-term gait level after hip replacement as the remodeling parameters.Gruen method was applied to quantify the BMD changes.Results At the postoperative initial stage,obvious variations existed in constant gait group and changing gait group.The maximum difference occurred in low gait group,resulting in the decrease of BMD by 41%in greater trochanter region.The improvement of gait level would promote the enhancement of BMD in proximal and middle region of the prosthesis,resulting in the increase of BMD by 47%.Long-term gait recovery would promote BMD recovery in middle and end region of prosthesis,with BMD increase by 2%-9%.Conclusions The research findings provide guidance for rehabilitation process of patients after hip replacement.