摘要目的 探讨自制股骨髓外定位截骨器的准确性及对术后疗效的影响.方法 自制股骨髓外定位截骨器,采用髓外力线杆与“T”型杆成直角连接和5°～7°外翻设计,保持定位模块固定螺钉与股骨上髁轴平行,通过髓外力线杆指向腹沟股中点完成股骨远端冠状面定位、髓外力线杆与股骨远端髓腔平行完成矢状面定位,对股骨远端进行定位截骨.2015年10月至2016年3月将60例拟行单侧全膝关节置换者随机分为两组,分别采用髓内定位和髓外定位方法.比较两组术中及术后失血量、术后1周深静脉血栓形成(deep vein thrombosis,DVT)发生率、术后2周膝关节外翻角和股骨假体屈曲角.2016年4月至2017年1月共273例单侧全膝关节置换术采用股骨髓外定位法,男78例,女195例;年龄57～82岁,平均(68.7±12.33)岁.术后1周行下肢彩色超声检查筛查DVT,术后2周测量膝关节外翻角和股骨假体屈曲角,术后6周测量膝关节活动度及评估美国特种外科医院(Hospital for Special Surgery,HSS)膝关节评分.结果 随机对照研究中,髓外定位组术中及术后失血量为(112.00±73.77) ml,明显少于髓内定位组的(256.00±82.62) ml,差异有统计学意义;术后1周DVT的发生率分别为6.7％(2/30)和20.0％(6/30),差异无统计学意义;术后2周膝关节外翻角分别为7.34°±0.59°和7.08°±0.77°,股骨假体屈曲角分别为6.36°±0.86°和6.14°±0.79°,差异均无统计学意义.回顾性研究中,273例平均手术时间为(60.13±13.69) min、术中及术后失血量为(109.11±70.73) ml.术后1周出现胭静脉血栓4例、胫后静脉血栓9例、肌间静脉血栓17例,DVT发生率为11.0％ (30/273).术后3个月内无一例出现症状性肺栓塞或脑栓塞.术后2周膝关节外翻角为7.34°±0.69°,77.3％(211/273)的患者误差在±3°范围内;股骨假体屈曲角为6.43°±1.59°,273例均在±10°误差范围内.术后6周HSS膝评分由术前(54.52±5.96)分提高至(86.20±4.92)分,关节活动度由术前100.88°±7.51°提高至110.42°±7.08°,手术前后差异有统计学意义.结论 全膝关节置换术中采用股骨髓外定位截骨器进行股骨远端测量和截骨可获得与髓内定位法相同的假体位置和力线,并能降低手术失血量和术后DVT的发生率.

abstractsObjective To investigate the outcome of a new designed extramedullary femoral osteotomy module and to compare with conventional intramedullary system in clinical study.Methods The extramedullary femoral osteotomy module was designed with the extramedullary alignment rod connecting with the T type rod at right angle,and it had a 5°-7° adjustable valgus design.The positioning module fixation screw was parallel with the epicondylar axis.The coronal plane of the distal femur bone cut was orientated by the extramedullary alignment rod pointing to the inguinal midpoint,and the sagittal plane was orientated by the extramedullary alignment rod keeping parallel with the distal femoral medullary cavity.The terminal distal femoral bone cut was conducted with suitable osteotomy after the orientation.Sixty patients who underwent unilateral total knee arthroplasty (TKA) from October 2015 to March 2016 were randomly divided into intramedullary and extramedullary group for prospective controlled study.Blood loss,drainage and the incidence of deep vein thrombosis (DVT) were evaluated at one week postoperatively.Knee valgus angle and femoral prosthesis flexion angle were analyzed at two weeks postoperatively.Moreover,the extramedullary femoral osteotomy module was used in 273 patients (78 males and 195 females) with an average age of 68.7 (range,57-82 years old) who underwent unilateral TKA from April 2016 to January 2017.Blood loss,operation duration and lower limb ultrasonography preoperatively and at one week postoperatively were recorded.Knee valgus angle and femoral prosthesis flexion angle were measured at 2 weeks postoperatively.Range of knee motion and Hospital for Special Surgery (HSS) knee score at six weeks postoperatively were also reported.Results In the randomized controlled trial,blood loss and drainage in extramedullary group was less than that in intramedullary group (t=-3.330,P=0.004).There was no significant difference in the incidence of DVT at 1 week postoperatively (x2=2.269,P=0.132) and the knee valgus angle and femoral prosthesis flexion angle at 2 weeks postoperatively within the two groups.In the clinical application,operation time was 60.13± 13.69 min,and blood loss and drainage was 109.11±70.73 ml.There were four cases of popliteal vein thrombosis,nine cases of posterior tibial vein thrombosis,and seventeen cases of muscular venous thrombosis at one week postoperatively.The incidence rate of DVT was 11.0％.There was no symptomatic pulmonary embolism at three months postoperatively.Knee valgus angle was 7.34°±0.69°,and 211 knees accounting for 77.3％ were in the range of ±3° error.Femoral prosthesis flexion angle was 6.43°±1.59°,and 273 knees were all in the range of ±10° error.Range of knee motion improved from 54.52±5.96 preoperative to 86.20±4.92 at six weeks postoperative.HSS knee score improved from 100.88°±7.51° preoperative to 110.42°±7.08° at six weeks postoperative.Conclusion The new designed extramedullary femoral osteotomy module used in distal femoral osteotomy during TKA can significantly reduce the risk of bleeding and the incidence rate of DVT postoperatively.Furthermore,patients can obtain as excellent prosthesis position and limb alignment as conventional intramedullary system.