颈脊柱姿势及椎间盘水化状态对颈脊柱运动单位整体压缩强度影响——体外力学分析

目的通过体外力学分析,研究颈脊柱姿势及椎间盘水化状态对颈脊柱运动单位整体压缩强度的影响。方法选用12具成人健康新鲜尸体颈段脊柱,解剖出C3-4、C5-6共24个运动单位(包括上下两个椎体和椎间盘)。施以压缩负荷,观察两种预负荷?状态(脱水和高度水化状态)和两种姿势(中立位和屈曲位)下颈段脊柱的极限压缩强度。通过解剖来明确颈椎的损伤。结果标本屈曲位时极限压缩强度比中立位时小(27%42%,P<0.001);在中立位外来负荷下,高度水化状态标本的极限压缩强度小于脱水状态的标本(29%,P<0.01)。结论晨起椎间盘高度水化状态下以及颈脊柱屈曲位时,受到外来负荷颈脊柱易损伤。

Affect of cervical spinal column posture and hydration on compressive strength--biomechanical study in vitro

Objective The purpose of this study was to investigate the affect of cervical spinal column posture andprior loading history on its motor unit compressive strength. Method 12 fresh human cadaver cervical spines wereharvested and dissected into 24 motion segments containing two vertebrae and the intervening disc (C34 and C56).Compressive loads were applied so that the effects of the limited compressive strength by the two loading historiesdehydrated and two failure postures (neutral, flexed) on the spine could be examined. Dissection techniques were usedto document tissue damage. Result Specimens in a flexed posture had a lower ultimate compressive strength(27%42%, P<0.001) than in a neutral posture. When in a neutral posture, super-hydrated specimens had a lowerstrength (29%, P<0.01) than dehydrated specimens. Conclusion The spine may be more prone to get injury early in themorning when the discs are at their t greatest level of hydration with a fully flexed posture.