Biomechanics characteristics of four anterior cervical reconstructive techniques in the surgical management of multilevel cervical spondylotic myelopathy:a finite element model study / 中国组织工程研究

ABSTRACT

BACKGROUND:Surgical treatment is commonly used for decompressing the spinal cord in multilevel cervical spondylotic myelopathy, but the optimum anterior cervical reconstructive method has not been determined. OBJECTIVE:To compare and analyze the biomechanical characteristics of four anterior cervical reconstructive techniques in the surgical management of multilevel cervical spondylotic myelopathy utilizing the three-dimensional finite element model. METHODS:A three-dimensional finite element model of an intact C2–7 segment was developed and validated based on healthy adult male CT images. Four additional models were developed from the fusion model, including anterior cervical discectomy and fusion, anterior cervical corpectomy and fusion, anterior cervical hybrid decompression and fusion and anterior cervical discectomy and fusion with Cage alone. Von Mises stresses on the plate and the disc of adjacent levels (C2/3, C6/7) were comparatively analyzed. RESULTS AND CONCLUSION:(1) The C2/3 disc stress in flexion, extension, lateral bending and rotation condition was significantly higher than the C6/7 disc in 4 anterior cervical reconstructive techniques, and the adjacent disc stress (C2/3, C6/7) was lowest in the anterior cervical discectomy and fusion with Cage alone, and highest in the anterior cervical corpectomy and fusion. (2) The stress at the plate-screw interface was highest in the anterior cervical corpectomy and fusion, and lowest in the anterior cervical discectomy and fusion. (3) In conclusion, among the four anterior cervical reconstructive techniques for multilevel cervical spondylotic myelopathy, the anterior cervical discectomy and fusion with Cage alone makes little effect on the adjacent disc stress, which might reduce the incidence of adjacent segment disease after fusion. However, the accompanying risk of the increased incidence of cage subsidence should never be neglected.