传统与改良Elmslie—Trillat术治疗髌骨不稳定的生物力学比较

Traditional versus modified Elmslie-Trillat procedures for patellar instability： a biomechanical study

目的 评价传统与改良Elmslie-Trillat术治疗髌骨不稳定的生物力学特性,为改良Elmslie-Trillat术治疗髌骨不稳定提供生物力学依据.方法 先对12具新鲜冰冻成人尸体膝关节完整标本（完整膝关节组,12具）进行生物力学测试测量髌骨移位距离,切断内侧髌股韧带制成髌骨不稳定模型（髌骨不稳定模型组,12具）后再测量髌骨移位距离,然后随机再分为2组（传统Elmslie-Trillat术组及改良Elmslie-Trillat术组,每组6具标本）分别采用传统和改良Elmslie-Trillat术矫正.膝关节屈曲30°位固定胫骨及股骨端,将标本安装在MTS-858实验机上,通过髌骨中心外侧施加20 N的载荷,测量髌骨移位距离.结果 完整膝关节组、髌骨不稳定模型组、传统Elmslie-Trillat术组及改良Elmslie-Trillat术组的髌骨外侧移位距离平均分别为（6.2±0.6）、（11.3±0.9）、（6.4±0.8）、（6.7±0.8）mm,4组外侧减内侧移位距离平均分别为（-1.5±0.5）、（3.5±0.4）、（-1.4±1.0）、（-1.3±1.0）mm.髌骨不稳定模型组的外侧移位距离和外侧减内侧移位距离分别与其他3组比较,差异均有统计学意义（P＜0.05）;完整膝关节组、传统Elmslie-Trillat术组及改良Elmslie-Trillat术组的外侧移位距离和外侧减内侧移位距离比较差异均无统计学意义（P＞0.05）.结论 内侧髌股韧带是髌骨的主要稳定因素.与传统Elmslie-Trillat术比较,改良Elmslie-Trillat术同样能改善髌骨异常力线,减少相同应力下的髌骨位移.

Objective To evaluate the biomechanical performance of the modified Elmslie-Trillat procedure in the treatment of patellar instability as compared with traditional Elmslie-Trillat procedure.Methods Twelve fresh frozen cadaveric specimens of intact knee joint were used in this study.First biomechanical measurements were performed to compare the patellar displacements between the intact knee joints and models of patellar instability which were made by cutting the medial patellofemoral ligaments.Next the models of patellar instability were randomized into 2 groups for treatments with traditional and modified Elmslie-Trillat procedures respectively.After the tibiofemoral joint was held at 30 degrees of flexion, a load of 20 N was applied to the lateral center of the patella.The patellar displacements were measured with transducers in an Instron Testing System.Results The lateral patellar displacement was respectively 6.2 ±0.6 mm, 11.3 ± 0.9 mm, 6.4 ± 0.8 mm and 6.7 ± 0.8 mm and the lateral minus medial patellar displacement was respectively - 1.5 ± 0.5 mm, 3.5 ± 0.4 mm, - 1.4 ± 1.0 mm and - 1.3 ± 1.0 mm for the 4 groups of intact knee joint, patellar instability, traditional Elmslie-Trillat procedure treatment and modified Elmslie-Trillat procedure treatment.There were significant differences in both of the patellar displacements between the patellar instability group and the other 3 groups （ P 〈 0.05）.There was no significant difference in both of the patellar displacements among the 3 groups of intact knee joint, traditional Elmslie-Trillat procedure treatment and modified Elmslie-Trillat procedure treatment （ P 〉 0.05 ）.Conclusion Since the medial patellofemoral ligament is a main stable factor for patella, patellar abnormal traction can be improved and patellar displacement can be reduced under the same loading by both modified and traditional Elmslie-Trillat procedures.