新型锚-袢内固定系统重建喙锁韧带治疗肩锁关节脱位的生物力学研究

A novel anchor-loop internal fixation system in coracoclavicular ligament reconstruction for acromioclavicular dislocation:a biomechanical study

目的通过尸体标本测试新型锚-袢内固定系统治疗肩锁关节脱位的生物力学稳定性,为临床治疗肩锁关节脱位提供新方法。方法12侧完整的肩关节标本切断肩锁韧带,首先进行喙锁韧带的准静态非破坏性循环实验,直至喙锁韧带失效,并记录喙锁韧带失效强度。12侧标本被随机分为A、B、C、D四组(n=3),分别使用3.5 mm锁骨钩锁定加压钢板、5 mm软组织带线锚钉、10 mm Endobutton钢板、新型锚-袢内固定系统(5 mm软组织带线锚钉+10 mm Endobutton钢板)4种不同内固定材料复位、固定肩锁关节。然后使用X线透视机正位透视复位后的肩锁关节,评估内固定位置及肩锁关节复位情况。最后使用自制的固定夹具将肩关节标本固定在100 KN电子万能力学试验机上,以100 mm/min的载荷速度对各实验标本在垂直方向进行破坏性的静态拉伸力学测定,通过与生物力学试验机相连接的计算机记录并描画载荷-位移曲线,记录各内固定的失效强度及原因。结果12侧尸体标本喙锁韧带断裂强度为(374.6±0.8)N。4组内固定失效的力学载荷及原因:A组为(409.5±2.6)N,两侧标本内固定失效原因为锁骨骨折,一侧标本为肩峰骨折;B组为(297.8±3.4)N,均为锚钉脱出;C组为(375.2±3.1)N,均为喙突基底部骨折;D组为(376.2±3.1)N,均为锚钉脱出。4个实验组内固定失效生物力学载荷差异有统计学意义(P<0.05)。D组与A组、B组内固定失效生物力学载荷差异均有统计学意义(P<0.05)。结论新型锚-袢内固定系统重建喙锁韧带能够有效复位肩锁关节并治疗肩锁关节脱位,符合肩锁关节的生物力学特性,操作简单,具有较高的可行性。

Objective To explore the biomechanical stability of a novel anchor-loop internal fixation system in the treatment of acromioclavicular joint dislocation using cadaveric specimens.Methods The acromioclavicular ligaments were severed in 12 complete shoulder joint specimens,in which the quasi-static non-destructive cycle experiment was performed until the coracoclavicular ligaments failed.The failure intensities of the coracoclavicular ligaments were recorded.Next,the 12 specimens were randomly divided into groups A,B,C and D(n=3),in which 4 different internal fixation materials were used respectively to reduce and fix the acromioclavicular joint.Group A was subjected to 3.5 mm clavicular hook locking compression plate,group B to 5 mm soft tissue with wire anchor,group C to 10 mm Endobutton steel plate,and group D to the novel anchor-loop internal fixation system(5 mm soft tissue with wire anchor+10 mm Endobutton steel plate).An X-ray machine was used to evaluate the reduction and internal fixation of the acromioclavicular joint.After the shoulder specimens were securely fastened by a homemade fixation jig to a 100 KN electronic universal mechanical testing machine,each experimental specimen was subjected to a destructive static tensile mechanic determination in the vertical direction at a loading speed of 100 mm/min.The load-displacement curves were recorded and drawn by a computer connected with the biomechanical testing machine.The failure strength and failure causes were recorded for each internal fixation.Results The fracture strength of the coracoclavicular ligament in 12 cadaver specimens was(374.6±0.8)N.The mechanical load of internal fixation failure was(409.5±2.6)N in group A,(297.8±3.4)N in group B,(375.2±3.1)N in group C and(376.2±3.1)N in group D.The internal fixation failure was due to clavicular fracture in 2 specimens and to acromial fracture in 1 specimen in group A,to anchor protrusion in all the 3 specimens in group B,to coracoid base fracture in all the 3 specimens in group C,and to anchor protrusion in all the 3 specimens in group D.The mechanical loads of internal fixation failure were significantly different among the 4 experimental groups(P<0.05).The mechanical load of internal fixation failure in group D was significantly different from that in groups A and B(P<0.05).Conclusions Our self-developed novel anchor-loop internal fixation system can effectively reposit the acromioclavicular joint to treat acromioclavicular joint dislocation,because it conforms to the biomechanical characteristics of the acromioclavicular joint,and is easy to handle.Therefore,its feasibility is high.