腰椎全韧带叠加损伤对腰椎生物力学特性的影响

Effect of total ligament superimposed injury on biomechanical characteristics of the lumbar spine

背景:韧带是稳定腰椎的重要结构,随着年龄的增长韧带容易发生退行性变化,目前关于腰椎韧带的研究较少。目的:探究在一定的韧带损伤顺序下,前屈、后伸、侧弯、扭转4种运动状态时,不同韧带叠加损伤的组合对腰椎生物力学特性的影响。方法:建立L4-L5节段腰椎有限元模型,施加相应的力矩模拟前屈、后伸、侧弯、扭转4种运动状态,按顺序进行韧带的组合损伤,得到腰椎的活动度及各个韧带的应力。结果与结论:①每去除一根韧带,剩余韧带应力会增加,4种工况下都是关节囊韧带所受应力最大,尤其是前屈时;随着韧带的去除,腰椎活动度也在不断增加;②前屈时,去除第一根韧带关节囊韧带后,剩余韧带应力变化平均值最大,其次是去除棘上韧带后;去除关节囊韧带后,腰椎活动度变化率最大,去除后纵韧带后,腰椎活动度变化率最小;③后伸时,所有韧带都是在去除关节囊韧带后应力变化率最大,去除关节囊韧带后,腰椎活动度变化率最大,去除后纵韧带后,腰椎活动度变化率最小;④侧弯时,棘间韧带的应力变化率在去除横突韧带后减小,棘上韧带此时增加较多,去除关节囊韧带和去除横突韧带后,活动度变化率有较大的增加;⑤扭转时,去除关节囊韧带后,剩余韧带应力变化率远大于其他韧带损伤组合;也是在去除关节囊韧带后,活动度变化率最大,其余情况活动度变化率不超过8%;⑥一根韧带损伤,其余韧带会进行应力补偿,韧带损伤会影响腰椎的稳定性,侧弯情况下影响最小,腰椎不稳患者要避免前屈和后伸运动,通过前屈和后伸运动更容易检查出韧带的病理状况;⑦关节囊韧带是维持腰椎稳定性的重要结构,棘上韧带在前屈中发挥了较大的作用,要保持腰椎全韧带的完整性。

BACKGROUND:Ligaments are an important structure for stabilizing the lumbar spine,and they are prone to degenerative changes with age.Currently,there is limited research on lumbar ligaments.OBJECTIVE:To investigate the effect of different combinations of ligament injuries on biomechanical characteristics of lumbar spine under four motion states of forward bending,backward extension,lateral bending,and torsion under a certain sequence of ligament injuries.METHODS:A finite element model of the L4-L5 segment of the lumbar spine was established,and corresponding moments were applied to simulate four motion states of forward bending,backward extension,lateral bending,and torsion.The combined injuries of the ligaments were performed in order to obtain the motion range of each vertebra and the stress of each ligament.RESULTS AND CONCLUSION:(1)Every time a ligament was removed,the remaining ligament stress would increase.Under all four working conditions,capsular ligament would experience the highest stress,especially during forward bending.With the removal of ligaments,the range of motion of the vertebrae was also continuously increasing.(2)When flexing forward,after removing the first ligament capsular ligament,the average stress change in the remaining ligament was the highest,followed by the removal of supraspinous ligament.After removing capsular ligament,the change rate of range of motion was the highest,while after removing posterior longitudinal ligament,the change rate of range of motion was the lowest.(3)When extending backward,all ligaments had the highest rate of stress change after removing capsular ligament,the highest rate of range of motion change after removing capsular ligament,and the lowest rate of range of motion change after removing posterior longitudinal ligament.(4)When bending,the stress change rate of interspinous ligament decreased after removing intertransverse ligament,while supraspinous ligament increased more.After removing capsular ligament and interspinous ligament,the range of motion change rate increased significantly.(5)During lateral bending,after removing capsular ligament,the stress change rate of the remaining ligament was much higher than that of other ligament damage combinations,and the range of motion change rate was the highest after removing capsular ligament.In other cases,the range of motion change rate did not exceed 8%.(6)If the root ligament is damaged,the remaining ligaments will undergo stress compensation.Ligament damage will affect the stability of the lumbar spine,with minimal impact in cases of lateral curvature.Patients with lumbar instability should avoid forward flexion and backward extension movements,which can make it easier to detect the pathological condition of the ligaments.(7)Capsular ligament is an important structure for maintaining lumbar stability,and supraspinous ligament plays a significant role in anterior flexion,maintaining the integrity of the entire lumbar ligament.