垫片改良设计对膝关节置换术后临床功能和膝关节运动的影响

目的 探讨膝关节假体垫片设计对膝关节置换术后临床功能和膝关节运动学的影响.方法 分析2007年7月至2009年6月使用GENESIS Ⅱ假体行全膝关节置换术的28例膝关节骨关节炎患者的临床资料,共42膝,平均随访27.7个月.按照使用垫片的种类分为高屈曲垫片组(男性1例,女性14例,23膝;年龄54～74岁,平均62.8岁)和标准组(男性1例,女性12例,19膝;年龄54～74岁,平均64.3岁).通过膝关节评分比较两组的临床功能.采用循环透视和软件分析的方法比较两组病例在膝关节屈伸活动时股骨后滚、伸膝装置力臂等参数,评价垫片设计对膝关节运动的影响.结果 标准组和高屈曲垫片组的术后活动度分别为120°和123°,差异无统计学意义.两组在膝关节学会评分上没有差异.高屈曲垫片组术后的Feller评分高于标准组,差异有统计学意义(P=0.012).在影像学测量上,两组病例在0～120°范围活动时股骨后滚和伸膝装置力臂的差异均无统计学意义;活动范围达到130°时,两组的伸膝装置力臂差异有统计学意义(P=0.034).结论 高屈曲垫片的改良设计在减少膝关节置换术后膝前痛的发生、改善膝关节功能方面有一定的作用;但可能会减小伸膝装置的力臂,从而影响股四头肌的做功.

Influence of the insert design on clinical results and kinematics of the knee after total knee arthroplasty

Objective To investigate the influence of the insert design of knee prosthesis on clinical results and kinematics of the knee after total knee arthroplasty (TKA). Methods Forty-two knees in 28 patients with knee osteoarthritis undergoing TKA using the GENESIS Ⅱ from July 2007 to June 2009 were included in this study, mean follow-up of 27.7 months. The cases were divided into 2 groups according to the type of insert, one was high flexion insert group (23 knees) and the other was standard insert group (19 knees). Two groups were compared by clinical ratings of knee function. The motion of flexion and extension of the two groups was observed by cyclic fluoroscopy and the data was analyzed by mapping software. The influence of the insert design of knee prosthesis on kinematics of the knee after TKA was investigated by comparing the parameters of the two groups during the movement of knee joint, including femoral roll back and extensor mechanism arm. Results The range of motion of standard insert group and high flexion insert group was 120° and 123° respectively with no difference between them. There was no difference of knee society clinical rating system in both groups. Feller score of high flexion insert group was higher than the standard insert group, the difference was significant statistically (P =0.012). In the imaging measurement, the two groups had no differences in femoral rollback and extensor mechanism arm during the 0 to 120° range of movement. The two groups appeared significant statistically (P = 0.034) in the extensor mechanism arm when flexion extended to 130°. Conclusions The high flexion improved design may play a certain role on reducing anterior knee pain and improving knee function after TKA. However, the improved design may be reduced the extensor mechanism arm when high flexion, so that affecting the work ablility of quadriceps.