3D打印技术辅助股骨远端截骨术治疗膝外翻畸形骨关节炎的疗效观察

Effectiveness of distal femoral osteotomy assisted by three-dimensional printing technology for correction of valgus knee with osteoarthritis

目的探讨3D打印技术辅助股骨远端截骨术(distal femoral osteotomy,DFO)治疗膝外翻畸形骨关节炎的临床疗效。方法2014年1月—2016年1月,收治膝外翻畸形骨关节炎患者12例(15膝)。男5例,女7例;年龄30~60岁,平均43.8岁。病程1~12年,平均6.6年。单膝9例,双膝3例。骨关节炎Koshino分级:Ⅰ级1例(1膝),Ⅱ级7例(9膝),Ⅲ级4例(5膝)。摄双下肢全长X线片,测量股胫角(femorotibial angle,FTA)为(160.40±2.69)°,远端股骨外侧角(anatomical lateral distal femoral angle,a LDFA)为(64.20±2.11)°。术前于Mimics软件设计截骨模块并3D打印,术中通过截骨模块确定最佳截骨方位进行截骨,最后行钢板及螺钉内固定。结果术后切口均Ⅰ期愈合,无感染、下肢深静脉血栓形成等并发症发生。患者均获随访,随访时间6~18个月,平均12.2个月。术后6个月膝关节HSS评分为(89.07±2.49)分,较术前(65.27±1.49)分显著提高(t=–28.31,P=0.00);获优10膝、良4膝、可1膝,优良率为93.3%。X线片复查示,患者截骨处均达骨性愈合,愈合时间2.9~4.8个月,平均3.3个月;1例(1膝)出现骨延迟愈合。术后6个月测量FTA为(174.00±1.41)°,a LDFA为(81.87±1.06)°,与术前比较差异均有统计学意义(t=–18.26,P=0.00;t=–25.19,P=0.00);下肢力线位置测量显示内侧胫骨平台占整个胫骨平台百分比为49.78%±0.59%,与术中测量的49.82%±0.77%比较,差异无统计学意义(t=0.14,P=0.89)。结论DFO治疗膝外翻畸形骨关节炎时,3D打印截骨模块可辅助术中股骨远端精确截骨,获得满意临床疗效。

Objective To evaluate the effectiveness of distal femoral osteotomy aided by three-dimensional （3D） printing cutting block for correction ofvaglus knee with osteoarthritis. Methods Between January 2014 and January 2016, 12 patients （15 knees） with vaglus deformity and lateral osteoarhritis underwent medial closing wedge distal femoral osteotomy. There were 5 males and 7 females, aged 30-60 years （mean, 43.8 years）. The mean disease duration was 6.6 years （range, 1-12 years）. The unilateral knee was involved in 9 cases and bilateral knees in 3 cases. According to Koshino＇s staging system, 1 knee was classified as stage I, 9 knees as stage Ⅱ, and 5 knees as stage Ⅲ The X-ray films of bilateral lower extremities showed that the femorotibial angle （FTA） and anatomical lateral distal femoral angle （aLDFA） were （160.40±2.69）°and （64.20±2.11）°respectively. Mimics software was used to design and print the cutting block by 3D printing technique. During operation, the best location of distal femoral osteotomy was determined according to the cutting block. After osteotomy, internal fixation was performed using a steel plate and screws. Results All incisions healed primarily; no complication of infection or deep vein thrombosis was observed. All patients were followed up 6-18 month （mean, 12.2 months）. At 6 months after operation, the hospital for special surgery （HSS） score for knee was significantly improved to 89.07±2.49 when compared with preoperative score （65.27±1.49, t=-28.31, P=0.00）; the results were excellent in 10 knees, good in 4 knees, and fair in I knee with an excellent and good rate of 93.3%. The bony union time was 2.9-4.8 months （mean, 3.3 months）. Bone delayed union occurred in 1 case （1 knee）. The postoperative FTA and aLDFA were （174.00±1.41）° and （81.87±1.06）° respectively, showing significant differences when compared with preoperative ones （t=-18.26, P=0.00; t=-25.19, P=0.00）. The percentage of medial tibial plateau in whole tibial plateau was 49.78%＋0.59%, showing no significant difference when compared with intraoperative measurement （49.82%±0.77%, t=0.14, P=0.89）. Conclusion 3D printing cutting block can greatly improve the accuracy of distal femoral osteotomy, and ensure better effectiveness for correction ofvaglus knee with osteoarthritis.