两种动力性颈椎前路钢板对颈椎稳定性的生物力学比较

Biomechanical comparison of two kinds of dynamic anterior cervical plate for cervical stability

目的:比较Codman和Window两种动力性颈椎前路钢板对颈椎单椎间减压植骨融合模型稳定性,为临床提供理论依据。方法:将12例小牛颈椎标本随机分成两组,用生物力学测定仪测定正常颈椎C4/5节段在前屈、后伸、左右侧屈、左右旋转时的三维运动范围(ROM),然后切除C4/5椎间盘,制成损伤模型,测定植骨加钢板,植骨块缩短1mm加钢板固定后C4/5节段的ROM,植骨块的长度根据测量椎间隙的高度而定。结果:Codman和Window两种钢板加植骨时的ROM在屈/伸、侧屈、旋转时相似,无显著性差异(P>0.05),其中在屈/伸时的ROM与正常标本相比小,有显著性差异(P<0.05),在侧屈时、旋转时与正常标本相比无显著性差异(P>0.05);在植骨缩短后,两种钢板的ROM均不同程度的变大,其中Codman组在屈/伸、侧屈、旋转时与正常标本相比无显著性差异(P>0.05),Window组在屈/伸时与比正常标本无显著性差异(P>0.05),但在侧屈、旋转时大,有显著性差异(P<0.05)。结论:Codman钢板在植骨与植骨块缩短后均能对颈椎提供有效的稳定性,Window钢板在植骨时能提供有效的稳定性,但在植骨缩短后不能对颈椎提供有效的颈椎稳定性。

Objective： To compare the stability of the Codman and Window dynamic anterior cervical plates on the single-level anterior intervertebral decompression and fusion model for offering a theoretical foundation in clinics. Methods： The total number of 12 C2-C7 specimens from fresh calf cervical spine were selected. All intact specimens underwent test to measure the ROM （range of motion） of C4/5 segment were divided at randomly into two groups （groups A, B）, with 6 specimens in each group. The model of single-level interverterbral decompression was made, and the specimens of A group were fixed with the Codman plates, B group with the Window plates. ROM of the following construct fixation with Codman plates, Window plates with grafts and lmm shortened grafts were measured respectively, and the graft height were determined for each specimens by physical measurement of discectomy site. Results： There was no significant difference between the ROM of the Codman plate with graft and that of the Window plate with graft in flex/extension, lateral bending and rotation （P〉0.05）. The ROM of the Codman plates and Window with grafts was less significantly than that of the intact specimen in flex/extension, similar to that of the intact specimen in lateral bending and rotation （P〉0.05）. The ROM of the Codman and Window plates with shorten grafts was more than that of the plates with grafts in some extent. The ROM of the Codman plates with shorten grafts was similar to that of the intact specimen in flex/extension, lateral bending and rotation （P〉0.05）. The ROM of the Window plates with shorten grafts was similar to that of the intact specimen in flex/extension （P〉0.05）, more significantly than in lateral bending and rotation （P〈0.05）. Conclusions： The Codman plates with grafts and shorten grafts, the Window plates with grafts can provide effective stability for cervical spine.