高屈曲假体加延长杆在晚期类风湿关节炎伴重度膝外翻畸形和严重骨质疏松患者中的临床疗效研究

Clinical Efficacy of High-flexion Prosthesis with Extension Pole in Patients with Advanced Rheumatoid Arthritis,Severe Knee Valgus Deformity and Osteoporosis

目的探讨晚期类风湿关节炎(RA)伴重度膝外翻畸形和严重骨质疏松患者膝关节置换术假体选择及临床效果。方法选取2008—2014年兰州军区总医院全军骨科中心关节外科采用髌旁内侧入路、常规截骨加单纯外侧软组织松解方法治疗晚期RA伴重度膝外翻畸形和严重骨质疏松患者27例(32膝)。18例(20膝)采用不保留后十字韧带型后稳定型常规假体:Nex Gen HF-Flex常规膝(后稳定型组),9例(12膝)采用Nex Gen HF-Flex常规膝+延长杆(后稳定型+延长杆组)。采用术前及末次随访时膝关节屈曲挛缩、关节活动度、股胫角等评价手术效果。结果手术时间60~120 min,平均75 min。随访时间2.0~7.5年,平均4.9年。后稳定型组和后稳定型+延长杆组末次随访时膝关节屈曲挛缩较术前减少、关节活动度较术前提高(P<0.05)。术前及末次随访时,后稳定型组与后稳定型+延长杆组膝关节屈曲挛缩、关节活动度比较,差异均无统计学意义(P>0.05)。所有患者外翻畸形得到纠正,后稳定型组和后稳定型+延长杆组末次随访时股胫角较术前减小(P<0.05)。术前及末次随访时,后稳定型组与后稳定型+延长杆组股胫角比较,差异均无统计学意义(P>0.05)。术后3例(3膝)有膝关节外侧不稳症状,给予膝关节支具保护;2例(3膝)术后1个月出现下肢静脉血栓,给予放置下腔静脉滤网;1例(1膝)术后发生腓总神经麻痹。其余患者随访期间未发生假体感染、假体周围骨折、异位骨化、假体松动及外翻等术后并发症。结论对晚期RA伴重度膝外翻畸形和严重骨质疏松患者在假体选择方面,后稳定型假体与后稳定型假体+延长杆在纠正外翻屈曲畸形、关节活动度和股胫角疗效等方面,未见差异,所有患者近期疗效满意,但对于此类患者而言,后稳定型假体+延长杆组稳定性较好,受RA病程进展影响较低。

Objective To investigate the selection and application effect of prosthesis for total knee arthroplasty（ TKA） for advanced rheumatoid arthritis（ RA） patients with severe knee valgus deformity and osteoporosis. Methods The participants enrolled in this study were 27 cases（ 32 knees） with advanced RA and severe knee valgus deformity and osteoporosis treated in Department of Joint Surgery,Orthopedic Center of PLA,General Hospital of Lanzhou Command from 2008 to 2014 by the conventional osteotomy and lateral soft tissue release via the medial patellar approach. During the surgery,18 cases（ 20knees） applied the Nex Gen HF-Flex prosthesis without retaining the posterior cruciate ligament（ posterior stability group）,and other 9 cases（ 12 knees） applied the Nex Gen HF-Flex prosthesis with extension pole（ posterior stability and extension pole group）. The postoperative curative effect was evaluated by comparing the flexion contracture of knee joint,range of joint motion and femorotibial angle before the surgery and during the last follow-up period. Results The duration of surgery was 60-120 min,with an average of 75 min. The follow-up period was 2. 0 to 7. 5 years,with an average of 4. 9 years. The last follow-up found that,the flexion contracture of the knee was improved and the range of joint motion was wider in both groups compared with before the surgery（ P〈0. 05）. Before the surgery and last follow-up,two groups had no significant differences in the flexion contracture of the knee and range of joint motion（ P〈0. 05）. Varus deformity was corrected in all patients. The last follow-up found that,the femorotibial angle was smaller in both groups compared with before the surgery（ P〈0. 05）. Before the surgery and last follow-up,two groups had no significant difference in the femorotibial angle（ P〉0. 05）. Three cases（ 3 knees） had knee lateral instability,and were given knee joint protection; 2 cases（ 3 knees） had venous thrombosis of lower extremity 1month after surgery,and were treated by implantation of inferior vena cava filter; 1 case（ 1 knee） had paralysis of common peroneal nerve; other patients had no postoperative complications such as prosthesis infection, periprosthetic fractures,heterotopic ossification,prosthesis loosening and valgus. Conclusion For advanced RA patients with severe knee valgus deformity and osteoporosis,both kinds of prostheses applied to the surgery can achieve satisfactory short-term effect,with no significant differences in correcting the valgus deformity and improving flexion contracture and range of joint motion. However,for the advanced RA with severe knee valgus deformity and osteoporosis patients,the prosthesis stability of the treatment with Nex Gen HF-Flex prosthesis with extension pole is much better,for it is affected less by the RA progression.