胫骨内翻畸形对全膝关节置换术胫骨假体对线影响的临床研究

Extra-Articular Tibia Vara Affects Radiological Outcome of Total Knee Arthroplasty

目的胫骨内翻畸形(tibia vara)是膝关节关节外畸形的一种特殊类型。胫骨内翻畸形会给全膝关节置换术中胫骨假体的正确对线和安装带来困难。本研究的目的在于:a)测量国人内翻膝关节骨关节炎患者的胫骨平台内翻角(tibial varus angle,TVA),分析胫骨内翻畸形在内翻膝关节骨关节炎患者中所占的比例;b)探讨胫骨内翻畸形对全膝关节置换术术后胫骨假体对线和临床功能的影响。方法本研究回顾了我科从2015年8月至2015年12月收治的连续60例女性内翻膝关节骨关节炎的全膝关节置换患者资料,将患者分为正常组和胫骨内翻畸形组两组,术前下肢全长X线片中测量髋膝踝角(hip knee ankle angle,HKA)、TVA,术前所有患者的膝关节功能评分采用美国膝关节协会(knee society score,KSS)评分和西大略湖麦克马斯特大学(Western Ontario McMaster Universities,WOMAC)评分系统,术后下肢全长X线片中测量HKA以及胫骨假体近端内侧角(medial proximal tibial angle,MPTA),采用KSS评分和WOMAC评分系统评价膝关节功能。结果正常组TVA为(0.69±0.44)°,胫骨内翻畸形组TVA为(2.53±0.56)°,两组差异具有统计学意义。60例患者平均TVA为(1.12±0.52)°。正常组中TVA为0°的患者9例,占正常组病例数的20%。胫骨内翻畸形组中TVA大于等于2°的患者14例,占胫骨内翻畸形组的100%,即TVA大于等于2°为胫骨内翻畸形,胫骨内翻组患者占总病例数的23.3%。术后正常组HKA为(178.8±1.5)°,大于术后胫骨内翻畸形组HKA(177±2.0)°。术后正常组HKA异常值(Outlier值)有2例,占正常组病例的4.3%;术后胫骨内翻畸形组HKA Outlier值有3例,占胫骨内翻畸形组病例的21.4%。术后正常组活动度(range of motion,ROM)为(112.0±11.5)°,大于胫骨内翻畸形组ROM(105±8.0)°,两组比较差异有统计学意义。正常组术后WOMAC评分为(15.6±3.2)分,胫骨内翻畸形组WOMAC评分为(16.8±4.0)分。正常组术后KSS功能评分为(92.5±3.5)分,胫骨内翻畸形组术后KSS功能评分为(94.0±2.4)分。结论本研究中有23.3%的女性内翻膝骨关节炎患者合并胫骨内翻畸形(TVA大于等于2°),女性内翻膝关节骨关节炎患者平均TVA为(1.12±0.52)°。术前TVA大于等于2°的患者行全膝关节置换术发生术后对线不良的风险显著增加,手术时须注意胫骨近端正确截骨以及胫骨假体偏外安装,以避免术后对线不良的发生。

Objective Tibia Vara is an extra-articular deformity,in which the development of medial proximal tibial growth is retarded because of dysplasia.Our objective is to measure tibial varus angle in patients with knee osteoarthritis,to analyze the proportion of patients with tibial varus deformity in patients with knee osteoarthritisand to investigate the effect of tibial varus deformity on the component alignment and clinical outcomes after total knee arthroplasty.Methods We retrospectively reviewed and selected sixty adult patients with varus knee osteoarthritis underwent TKA between from August 2015 to December 2015.The patients were divided into two groups as the tibia vara group and the non-tibia vara group.Two surgeons measured the tibia vara angle （TVA） and Hip knee ankle angle （HKA） in preoperative radiography.All patients were also recorded with the American Knee Society score and WOMAC score preoperatively.After surgery,the HKA and medial proximal tibia angle （MPTA） were measured in long-standing radiography.Patients＇ KSS score and WOMAC score were also recorded.Results The mean TVA was （0.69±0.44）° in non-tibia vara group,while the mean TVA was （2.53±0.56）° in tibia vara group.The mean TVA in all patients was （1.12±0.52）°.Nine patients （20%） had TVAs of 0° in in non-tibia vara group.Fourteen patients （100%） had TVAs of more than 2° in tibia vara group.All patients in tibia vara group had TVAs of more than 2 degree.14 out of 60 patients （23.3%） had of more than 2 degree.The mean HKA was （178.8±1.5）＆#176;in non-tibia vara group,while the mean HKA was（177±2.0）° in tibia vara group.After TKA,two patients （4.3%） had HKA Outlier in non-tibia vara group,but three ones （21.4%） had HKA Outlier in tibia vara group.The mean range of motion （ROM） was （112.0±11.5）° in non-tibia vara group,while the mean ROM was （105±8.0）° in tibia vara group.The mean WOMAC score was （15.6±3.2） in normal group,while the mean WOMAC score was （16.8±4.0） in tibia vara group.The mean KSS function score was （92.5±3.5） in normal group,while the mean KSS function score was （94.0±2.4） in tibia vara group.Conclusion 23.3% patients of Chinese female people scheduled for TKA had tibia vara （TVA≥2°）.The mean TVA in female patients with knee arthritis was （1.12±0.52）°.An TVA greater than 2 degree was found to have a statistically significant influence on postoperative MPTA.Accurate proximal tibial cutting and tibial component lateralized is suggested,if the degree of tibia vara is considable significant.