限制性衬垫在老年患者初次膝关节置换中的应用

背景：内外翻限制性衬垫严格遵循“以最低的限制性获得可靠的稳定性”的原则，在提高假体的稳定性的同时又不增加限制级别。 目的：回顾性分析限制性衬垫在老年初次膝关节置换中内外翻不稳定的应用经验，总结限制性衬垫使用的适应证及临床效果。 方法：2010年3月至2012年3月间收治合并膝内外翻畸形的70例初次膝关节置换老年病例，其中内翻56例(平均15°-30°)；外翻14例(平均10°-20°)。70例中在完成标准截骨和软组织平衡操作后出现一侧    < 6 mm内外翻不稳定的23例(25膝)使用了限制性衬垫，其中内翻不稳18膝，外翻不稳7膝。23例均使用施乐辉公司普通骨水泥型膝关节假体，均未使用假体延长柄，11膝术中使用了骨水泥或自体骨植骨填补骨缺损。 结果与结论：平均随访2年(18-42个月)，所有病例膝关节疼痛消失，关节稳定，下肢力线纠正，KSS评分从置换前平均39.4分，提高到置换后的平均88.5分。所有患者均无需膝关节支具保护，膝关节最大屈曲度平均110°(96°-130°)，SF-36问卷满意度98%，无感染及脱位等并发症。结果提示在膝关节置换时完成截骨和软组织平衡后出现<6 mm内外翻不稳定时使用限制性衬垫，在老年初次膝关节置换中可以保留骨量，简化手术操作，近期临床效果良好。中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程全文链接：

Application of constrained polyethylene insert to primary total knee arthroplasty in older patients

BACKGROUND:Valgus-varus constrained polyethylene insert is selected in strict accordance with the principle of “to obtain reliable stability using minimum restriction”. The stability of the prosthesis is elevated, but the restriction is not increased. OBJECTIVE:To retrospectively analyze the application experience of constrained polyethylene insert in valgus and varus instability of primary total knee arthroplasty for older patients and to summarize the indications and clinical effects of this kind of implements. METHODS:From March 2010 to March 2012, a total of 70 patients combined valgus and varus malfomation who accepted primary total knee arthroplasty were enrolled in this study, including 56 varus patients (averagely 15°-30°) and 14 valgus patients (averagely 10°-20°). Constrained polyethylene insert was performed in 23 patients (25 knees) who still had remaining unilateral valgus or varus < 6 mm (18 patients were varus instability and 7 patients were valgus instability) when finished operation of standard osteotomy and soft tissue balancing. The bone cement knee prostheses in 23 cases were purchased from Smith & Nephew. The stem implant was not used in all cases. Cement or autografts were used in 11 valgus knees to fill the bone defects. RESULTS AND CONCLUSION:Patients were followed up for 2 years on average (18-42 mouths). The knee pain symptoms of all cases disappeared. The joint stability was obviously improved. The lower limb power lines were correct. The Knee Society Score scores were improved from an average of 39.4 points preoperation to an average of 88.5 points postoperation. All cases did not need the protection of knee braces. The maximum degree  of flexion was 110°(96°-130°). The satisfaction degree of 36-Item Short Form Health Survey was 98%. No dislocation or infection happened. Results indicated that constrained polyethylene insert could be applied in the cases of less than 6 mm valgus and varus instability when finished operation of standard osteotomy and soft tissue balancing in total knee arthroplasty for older patients. This kind of implements can preserve bone mass, simplify operational process and have good clinical outcome in a short period.