人工全膝关节置换术治疗膝内翻对患者后足力线角度的影响

Effects of total knee arthroplasty on the angle of hindfoot alignment in patients with varus knee

目的评估人工全膝关节置换前后患者后足力线角度的变化情况。方法前瞻性取2017年7月至2018年7月首都医科大学附属北京友谊医院收治的135例行人工全膝关节置换的患者,均为膝内翻、行单侧膝关节置换患者。术前及术后3个月拍摄双下肢全长负重正位及后足力线X线片,测量并比较术前及术后膝内翻角度和后足力线角度的变化。根据术前后足力线内外翻状态将患者分为后足外翻组(105例)和后足内翻组(30例),比较两组患者的膝内翻角度和后足力线角度的变化情况。结果135例患者中,总体膝内翻角度由术前内翻-9.34°±5.69°减少为术后内翻-2.34°±2.97°,差异具有统计学意义(P<0.001);后足力线由术前外翻2.89°±3.91°减少为术后外翻0.78°±3.77°,差异具有统计学意义(P<0.001)。分组分析显示,后足内翻组膝内翻角度由术前内翻-5.69°±3.39°减少为术后内翻-1.34°±2.86°,差异具有统计学意义(P<0.001);后足力线角度由术前内翻-1.95°±1.43°增大为术后内翻-3.71°±2.93°,差异具有统计学意义(P<0.001)。后足外翻组膝内翻角度由术前内翻-10.38°±5.80°减少为内翻-2.62°±2.95°,差异具有统计学意义(P<0.001);后足力线角度由术前的4.27°±3.24°减少为术后2.06°±2.90°,差异具有统计学意义(P<0.001)。结论随着膝内翻患者行人工全膝关节置换术后膝内翻的纠正,总体后足力线角度也相应发生变化。对于术前存在后足外翻的患者,膝关节置换术后其后足力线角度的度数会减少;对于术前存在后足内翻的患者,膝关节置换术后其后足内翻反而会进一步加重。

Objective To evaluate the change in hindfoot alignment before and after total knee arthroplasty.Methods 135 patients who underwent unilateral total knee arthroplasty for varus knee in Beijing Friendship Hospital,Capital Medical University from July 2017 to July 2018 were enrolled in this prospective study.The full-leg standing and hindfoot alignment radiographs were performed before and three months after the operation,and the angles of knee varus and hindfoot alignment were measured and compared.According to the preoperative hindfoot alignment states,the patients were divided into two groups:the hindfoot valgus group(n=105)and hindfoot varus group(n=30).Then the changes in knee varus angle and hindfoot alignment were compared within each group.Results In 135 patients,the overall knee varus angle significantly decreased from preoperative varus-9.34°±5.69°to postoperative varus-2.34°±2.97°(P<0.001),and the hindfoot alignment significantly decreased from preoperative valgus 2.89?±3.91°to postoperative valgus 0.78°±3.77°(P<0.001).In hindfoot varus group,the knee varus angle significantly decreased from-5.69°±3.39°to-1.34°±2.86°(P<0.001).The hindfoot alignment angle significantly increased from preoperative varus-1.95°±1.43°to postoperative varus-3.71°±2.93°(P<0.001).In hindfoot valgus group,the knee varus angle significantly decreased from-10.38°±5.80°to-2.62°±2.95°(P<0.001),and the hindfoot alignment angle significantly decreased from 4.27°±3.24°to 2.06°±2.9°(P<0.001).Conclusion With the correction of varus knee angle after total knee arthroplasty in patients with knee varus,the hindfoot alignment also changes accordingly.For the patients with hindfoot valgus before operation,the degree of hindfoot valgus will decrease after knee arthroplasty,and for the patients with hindfoot varus before operation,the hindfoot varus will further aggravate after knee arthroplasty.