前路手术治疗多节段颈椎退变的临床及生物力学研究

目的探讨多节段颈椎病前路手术的治疗结果,并采用力学方法评价内固定对颈椎稳定性的影响.方法 38例多节段颈椎病患者分为二组,A组:颈椎前路减压加椎体间植骨;B组:颈椎前路减压、植骨,加内固定.生物力学实验:6具成年颈椎标本分别进行三个椎间盘切除;椎间隙植骨;植骨加内固定等处理,并进行轴向压缩(300 N)、侧弯(2 Nm),及轴向扭转(2 Nm)加载.结果 A组中植骨块脱出发生率为45%,平均移位22%;骨不连发生率10%;术后神经功能优良率75%.B组无植骨块脱出,颈椎融合率100%;术后神经功能优良率83%.生物力学实验结果:3个节段的椎间盘切除后,颈椎在多个方向上的严重失稳,植骨可部分改善稳定性,内固定后明显改善颈椎稳定.结论应用颈椎前路内固定能预防植骨块的移位,增加颈椎融合率,提高临床疗效.

The clinical analysis and biomechanical study of anterior cervical spinal decompression with bone grafting and fixation for the multilevel cervical degenerative disorder

Objective This paper is to review the clinic results of the 38 cases treated with more than three levels anterior decompression and to evaluate the stabilization of the cervical spine in biomechanics.Methods The clinical study was done on the 38 consecutive cervical spondylosis patients affected with more than three cervical levels, who were separated into 2 groups. In group A, 20 cases were treated with anterior decompression and grafting with autogenous bone grafting. In group B, another 18 cases were treated with anterior decompression and grafting with autogenous bone grafting fixed with anterior plate systems. The biomechanic study was done with 6 fresh normal human cervical spine specimens. The cervical specimen were tested by the load of compression (300 N), lateral bending (2 Nm), and rotation (2 Nm) on the intact cervical spine, three levels discolectomy, grafting with three cortical bone, and fixed with locked plate. Results In the clinical study, early X ray showed the grafting bone was dislocated anteriorly of 22 percent in group A, the average of the shift was 22%. No union and pseudoarthrosis was developed in 10%. The rate of excellent and good in evaluation of the neurofunction in group A was 75%. In group B, all cases had bony fusion without grafting dislocation, and the rate of excellent and good was 83%. In the biomechanics study, the cervical spine was instabilizated seriously in 3 directions after three levels discolectomy. The stability could be improved partly by bone grafting, and be improved obviously by the cervical plates.Conclusion The application of the cervical plate could improve the stability, prevent the dislocation of the bone grafting and no union after multi-level anterior decompression of the cervical spine.