全膝关节置换后假体周围应力及骨密度变化评估

摘要

Objective To discuss changes of stress and bone mineral density around the prosthesis after total knee arthroplasty. Methods 80 cases with knee injury or disease from Jan 2011 to Jan 2013 were divided randomly into observation group and control group,each group of 40 cases. The control group was treated with conservative treatment,and the observation group was treated with total knee arthroplasty. Following up for 9 months,knee joint function recovery of two groups was compared. Following up for 2 years,changes of stress and bone mineral density in different ROI regions in different periods detected with three dimensional finite element analysis method and X ray bone density measuring method of two groups were evaluated. Results Following up for 9 months,HSS after treatment of observation group was higher than control group( P ﹤0. 05). In observation group,stress shielding rate of each partition after 6 months of treatment was highest,which was higher than 1 month( P ﹤0. 05). Bone density of observation group after 1 month of treatment showed no significant difference with uninjured side( P ﹥ 0. 05). Bone den-sity of observation group after 6 months,9 months,1 year,2 years were lower than uninjured side( P ﹤ 0. 05),and ROI5 area difference was particularly significant( P ﹤ 0. 01). Conclusion Total knee arthroplasty can promote the recovery of joint function,but stress and bone mineral density(BMD)around the prosthesis will change,and adopting effective methods to evaluate,can monitor prognosis and improve the long - term curative effect.%目的：探讨在行全膝关节置换术后，假体周围骨密度及应力变化评估方法。方法从2011年1月至2013年1月收治的膝关节损伤或病变患者中选取80例为研究对象，随机分为观察组40例和对照组40例。对照组行保守方法治疗，观察组行全膝关节置换术。治疗后对两组患者进行9个月随访，观察两组患者膝关节功能恢复情况。同时对观察组患者进行2年随访，采用三维有限元分析方法及 X 射线骨密度仪测量法，对患者不同时期各 ROI 区应力及骨密度变化进行评估。结果9个月随访结果显示，观察组治疗后 HSS 评分较对照组明显升高，差异存在统计学意义（ P﹤0.05）；观察组患者行置换术治疗6个月后，各分区应力遮挡率最高，同治疗后1个月对比，差异存在统计学意义（ P﹤0.05）；观察组患者经置换术治疗1个月，骨密度同健侧对比，无显著差异（ P ﹥0.05），治疗后6个月、9个月、1、2年，骨密度同健侧对比，明显较低，差异存在统计学意义（ P ﹤0.05），而 ROI5区差异尤为显著（ P ﹤0.01）。结论全膝关节置换术可促进患者关节功能恢复，但假体周围应力及骨密度会出现变化，采取有效方法进行评估，可对预后情况进行监测，提高远期疗效。