全膝关节置换术治疗膝外翻的矫正程度对临床疗效的影响

Influence of correction degree on the clinical effect of valgus knee after total knee arthroplasty

目的探讨全膝关节置换术(TKA)治疗膝外翻的矫正程度对临床疗效的影响。方法回顾性分析2015年1月至2018年12月东南大学附属中大医院骨科收治的91例因单侧膝外翻行TKA的患者资料。根据患者术后2周测量的髋-膝-踝角(HKA),分为中立位组(-3°≤HKA≤3°)和残留外翻组(HKA>3°)。中立位组70例,其中男性23例,女性47例,年龄[M(QR)]71.5(10.5)岁(范围:57~91岁);残留外翻组21例,其中男性8例,女性13例,年龄70.0(10.0)岁(范围:60~85岁)。收集两组患者术前和末次随访时的临床指标,包括关节活动度(ROM)、美国膝关节协会评分(KSS)、西安大略和麦克马斯特大学(WOMAC)骨关节炎指数和关节遗忘评分-12(FJS-12);影像学指标包括股骨角、胫骨角、股骨假体屈曲角、胫骨假体后倾角、髌骨倾斜角和适合角。记录患者术后并发症发生情况。组间比较采用独立样本t检验、Mann-Whitney U检验或χ^(2)检验。结果中立位组和残留外翻组患者术后ROM[(122.5±8.5)°比(119.4±7.1)°,t=1.534,P=0.128]、KSS[(159.8±8.9)分比(150.0±8.9)分,t=-0.103,P=0.918]、WOMAC骨关节炎指数[10.0(3.0)比9.0(5.0),Z=-0.733,P=0.464]和FJS-12[52.1(8.4)分比50.1(7.5)分,Z=-0.594,P=0.553]的差异均无统计学意义;股骨角[94.0(4.0)°比94.0°(5.0°),Z=-0.209,P=0.835]、胫骨角[90.0°(3.0°)比91.0°(2.5°),Z=-1.226,P=0.220]、股骨假体屈曲角[3.0(1.0)°比3.0(1.0)°,Z=-0.652,P=0.514]、胫骨假体后倾角[4.0°(2.0°)比4.0°(2.0°),Z=-0.763,P=0.445]、髌骨倾斜角[9.0°(3.0°)比9.0°(3.5°),Z=-1.429,P=0.153]和适合角[14.0°(4.0°)比15.0°(4.0°),Z=-1.690,P=0.091]的差异亦无统计学意义;但残留外翻组髌骨倾斜角和适合角的异常比例高于中立位组(33.3%比11.4%,χ^(2)=5.630,P=0.018;38.1%比17.1%,χ^(2)=4.136,P=0.042)。所有患者均获得随访,随访时间(32.1±5.2)个月(范围:24~40个月)。术后6周,残留外翻组出现1例关节僵直,经手法松解和康复锻炼后改善;末次随访时,残留外翻组出现2例髌骨不稳,予髌骨支具固定和加强股内侧肌肌力锻炼;两组均未出现髌骨脱位、关节不稳和假体无菌性松动等需再手术病例。结论膝外翻患者行TKA术后残留外翻对近期临床疗效无明显影响,但术后髌骨倾斜角和适合角的异常比例高,存在术后髌骨不稳风险,中远期疗效有待进一步评估。

Objective To investigate the influence of correction degree on the clinical effect of valgus knee after total knee arthroplasty(TKA).Methods Clinical data of 91 patients with unilateral valgus knee who underwent TKA from January 2015 to December 2018 at Department of Orthopaedic Surgery,Zhongda Hospital,Southeast University were retrospectively analyzed.According to postoperative hip-knee-ankle angle(HKA),these patients were divided into neutral group(-3°≤HKA≤3°)and residual valgus group(HKA>3°).There were 70 patients in the neutral group,with a median age of 71.5 years(range:57 to 91 years),and 21 patients in the residual valgus group,with a median age of 71.5 years(range:60 to 85 years).The postoperative clinical indicators,including the range of motion(ROM),American Knee Society score(KSS),Western Ontario and McMaster University(WOMAC)osteoarthritis index,forgotten joint score(FJS-12)were collected.Meanwhile,the imaging indexes of femoral angle,tibial angle,femoral prosthesis flexion angle,tibial prosthesis posterior slope angle,patella tilt angle,congruence angle were also collected.Additionally,postoperative complications were recorded.The clinical data were analyzed by independent sample t test,Mann-Whitney U test orχ^(2) test.Results There were no differences between the two groups in postoperative ROM(122.5°±8.5°vs.119.4°±7.1°,t=1.534,P=0.128),KSS(159.8±8.9 vs.150.0±8.9,t=-0.103,P=0.918),WOMAC osteoarthritis index(10.0(3.0)vs.9.0(5.0),Z=-0.733,P=0.464),FJS-12(52.1(8.4)vs.50.1(7.5),Z=-0.594,P=0.553)and femoral angle(94.0°(4.0°)vs.94.0°(5.0°),Z=-0.209,P=0.835),tibial angle(90.0°(3.0°)vs.91.0°(2.5°),Z=-1.226,P=0.220),femoral prosthesis flexion angle(3.0°(1.0°)vs.3.0°(1.0°),Z=-0.652,P=0.514),tibial prosthesis posterior slope angle(4.0°(2.0°)vs.4.0°(2.0°),Z=-0.763,P=0.445),patella tilt angle(9.0°(3.0°)vs.9.0°(3.5°),Z=-1.429,P=0.153),congruence angle(14.0°(4.0°)vs.15.0°(4.0°),Z=-1.690,P=0.091).However,abnormal proportions of patella tilt angle(33.3%vs.11.4%,χ^(2)=5.630,P=0.018)and congruence angle(38.1%vs.17.1%,χ^(2)=4.136,P=0.042)were apparent in the residual valgus group.The patients were follow-up for(32.1±5.2)months(range:24 to 40 months).Six weeks after operation,one case of joint stiffness occurred in the residual valgus group,which was improved after manual relaxation and rehabilitation exercises.At the last follow-up,two cases in the residual valgus group suffered patella instability which were fixed by patella braces and strengthening of the medial femoral muscles.There were no cases requiring reoperation for dislocation of patella,joint instability and aseptic loosening of the prosthesis in both groups.Conclusions Residual valgus after TKA for valgus knee has no significant effect on the short-term clinical outcome,but it is more likely to cause abnormal proportions of patella tilt angle and congruence angle which may induce the risk of postoperative patella instability.The mid-and long-term outcomes need to be further investigated.