术前MRI测量对提高全膝关节置换股骨假体外旋角度准确性的意义

Clinical research of preoperative MRI measurement to improve the accuracy of external rotation angle of femoral prosthesis in total knee arthroplasty

目的探讨术前MRI测量对提高全膝关节置换股骨假体外旋角度准确性的意义。方法回顾分析2018年1—6月福建医科大学附属闽东医院关节外科收治的行全膝关节置换术的52例膝关节骨性关节炎终末期患者的病历资料。将术前未行膝关节MRI检查的患者设为综合组,将术前行膝关节MRI检查的患者设为MRI测量组,每组26例。综合组根据外科通髁线(sTEA)及Whiteside线确定股骨后髁截骨线;MRI测量组通过MRI影像图片测量股骨后髁轴线(PCL)与sTEA线的夹角(即PCA角),术中根据PCA角行股骨后髁截骨。两组患者手术均由同一主刀医生完成,采用同一手术入路,截骨顺序相同,人工膝关节假体种类及手术步骤相同。术后行CT轴位像测量PCA角,统计分析两组术后股骨假体外旋角度安放的准确性。结果综合组股骨外旋角度安放不良率8.6%,MRI测量组为2.5%,差异有统计学意义(P<0.05)。MRI测量组股骨平均外旋角度为4.8°±2.1°。结论通过MRI测量发现股骨后髁外旋角存在差异,基于术前MRI测量的PCA角行股骨后髁截骨可明显提高全膝关节置换股骨假体外旋角度的准确性,提高全膝关节置换的精准度。

Objective To investigate the accuracy of preoperative MRI measurement to improve the external rotation angle of femoral prosthesis in total knee arthroplasty.Methods From January to June 2018,52 patients underwent total knee arthroplasty in the Department of Joint Surgery,Mindong Hospital Affiliated to Fujian Medical University were divided into 2 groups.Those who had received preoperative knee MRI were in the MRI measurement group and those who had not received knee MRI were in the comprehensive group.Each group involved 26 cases.In the comprehensive group,surgical transepicondyle axis(sTEA)and the Whiteside line were used to determine the posterior femoral condyle osteotomy line.In the MRI measurement group,preoperative MRI scan of the knee was performed to measure the PCA angle which between the femoral posterior condyle line(PCL)and the sTEA line.In operation,osteotomy of the femoral posterior condyle was performed according to this angle.Both groups of patients were reviewed CT measurement of the included angle femoral(post condylar angle,PCA).All patients in the 2 groups were performed surgery by the same surgeon with the same approach and procedure by the same prosthesis and operating tools.After surgery,PCA angle value was measured by CT axial imaging,and the accuracy of external rotation angle placement of femoral prosthesis was statistically analyzed.Results The reject ratio of external rotation angle of femur was 8.6%in the comprehensive group and 2.5%in the MRI measurement group;the difference was significant(P<0.05).The mean external rotation angle of femur was 4.8°±2.1°in the MRI measurement group.Conclusions The difference of external rotation angle of femoral condyle can be found by MRI measurement.The accuracy of external rotation angle of femoral prosthesis for total knee arthroplasty can be significantly improved by posterior femoral condyle osteotomy according to the preoperative MRI measurement angle.