Objective: To evaluate the effects of the improved precision alignment method of lower limbs mecha-nical alignment for osteoarthritis of the knee in open wedge high tibial osteotomy (OWHTO).
Methods: A retrospective analysis was made on the clinical data of 62 patients (68 knees) with knee osteoarthritis in the medial compartment treated with OWHTO between January 2012 and December 2015 who accorded with the inclusion criteria. The traditional method for positioning lower limb mechanical force line was used in 29 cases (32 knees) (traditional group), and improved method for positioning lower limb mechanical force line in 33 cases (36 knees) (modified group). There was no significant difference in gender, age, side, course of disease, and osteoarthritis grading between two groups ( P>0.05) with comparable. The operation time, intraoperative fluoroscopy times, and intraoperative blood loss were recorded in two groups; Before and after operation, the lower limb mechanical force line was observed on the X-ray films, which was expressed by hip-knee-ankle angle (HKA). The clinical efficacy was evaluated by the American Hospital for Special Surgery (HSS) score, and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC).
Results: Incision hematoma occurred in 1 case of traditional group and was cured at 3 weeks after symptomatic treatment; and primary healing was obtained in the other patients, with no early complications. The operation time and intraoperative fluoroscopy times of the modified group were significantly lower than those of the traditional group ( t=11.934, P=0.000; t=11.663, P=0.000), but there was no significant difference in blood loss between the two groups ( t=0.209, P=0.835). The patients were followed up for 6 to 24 months (mean, 12.7 months) in the traditional group and for 3 to 22 months (mean, 13.2 months) in the modified group. The medial knee pain disappeared in all patients. At last follow-up, the HSS score and WOMAC score were significantly improved when compared with preoperative scores in two groups ( P<0.05), but there was no significant difference between the two groups ( P>0.05). Postoperative X-ray examination showed that the tibiofemoral angle was corrected in the two groups. The HKA angle at immediate after operation and last follow-up was significantly higher than angle at pre-operation in two groups ( P<0.05), but there was no significant difference between at immediate after operation and at last follow-up ( P>0.05).
Conclusion: Compared with the traditional method for positioning lower limb mechanical force line, the improved precision alignment method can reduce the times of intraoperative fluoroscopy and shorten the operation time, which reduces the radiation exposure of both doctors and patients.
目的: 探讨采用下肢机械力线改良精准对线方法行开放楔形胫骨高位截骨术（open wedge high tibial osteotomy，OWHTO）治疗膝关节骨关节炎的疗效。.
方法: 回顾分析 2012 年 1 月—2015 年 12 月收治并符合选择标准的 62 例（68 膝）接受 OWHTO 的膝关节内侧单间室骨关节炎患者临床资料。其中，2012 年 1 月—2014 年 3 月共 29 例（32 膝）患者术中采用传统方法定位下肢机械力线（传统组），2014 年 4 月—2015 年 12 月共 33 例（36 膝）患者术中采用改良方法定位下肢机械力线（改良组）。两组患者性别、年龄、侧别、病程、骨关节炎分级等一般资料比较，差异均无统计学意义（ P>0.05），具有可比性。记录两组手术时间、术中透视次数、术中失血量；手术前后摄双下肢全长 X 线片，观测术侧下肢机械力线，以髋膝踝角（hip-knee-ankle angle，HKA）表示；采用美国特种外科医院（HSS）评分、美国西部 Ontario 与 McMaster 大学骨关节炎指数评分（WOMAC）评价临床疗效。.
结果: 术后传统组 1 例截骨部位切口发生血肿，经对症处理后 3 周愈合；其余患者术后切口均Ⅰ期愈合，无早期并发症发生。改良组手术时间、术中透视次数，均低于传统组（ t=11.934， P=0.000； t=11.663， P=0.000）；但两组术中失血量比较，差异无统计学意义（ t=0.209， P=0.835）。两组患者均获随访，其中传统组随访时间 6～24 个月，平均 12.7 个月；改良组随访时间 3～22 个月，平均 13.2 个月。患者膝关节内侧间隙疼痛症状均消失。末次随访时，两组 HSS 评分以及 WOMAC 评分与术前比较，差异均有统计学意义（ P<0.05）；两组间比较，差异均无统计学意义（ P>0.05）。术后 X 线片复查示，两组患者股胫角均得到纠正。两组术后即刻及末次随访时 HKA 角较术前提高（ P<0.05）；术后两时间点间比较，差异无统计学意义（ P>0.05）。.
结论: 与传统下肢机械力线定位方法相比，OWHTO 术中采用下肢机械力线改良精准对线方法，可减少术中透视次数、缩短手术时间，减少了医患双方辐射暴露。.
Keywords: Knee joint; lower limb mechanical alignment; open wedge high tibial osteotomy; osteoarthritis.