幼猪脊柱侧凸模型中椎体与椎间盘楔形变的进展规律及其意义

Progression of vertebral and disc wedging in immature porcine scoliosis model and its significance

中文关键词:  脊柱侧凸  力学  椎体  椎间盘  楔形变

英文关键词:Scoliosis  Biomechanics  Vertebrae  Disc  Wedging

中文摘要:

  【摘要】 目的：探讨幼猪脊柱侧凸模型中椎体和椎间盘楔形变随拴系固定时间变化的规律及其意义。方法：对7只后路不对称性拴系造模成功的侧凸幼猪在术后即刻、4周、8周分别进行全脊柱后前位X线片检查，应用Cobb法测量侧凸范围内每个椎体和椎间盘的楔变角，分析顶椎及其上、下各两个椎体和相应的4个椎间盘的楔变角在拴系时期内变化的规律，并计算不同时期内所有椎体楔变角之和与所有椎间盘楔变角之和分别占整个侧凸Cobb角的百分率。结果：顶椎区椎体楔变角随拴系固定时间发展逐渐增大,从拴系术后即刻时的1.1°，增大到术后8周时的43.3°，顶椎区椎体和椎间盘楔变角均呈现从顶椎向两侧端椎区逐渐减小趋势。在拴系术后即刻，侧凸几乎完全为椎间盘楔形变造成（96.8％），随时间发展，椎体楔变角占Cobb角的比值逐渐上升，至拴系固定8周时，Cobb角的构成变化为以椎体楔变角为主（71.5%）。结论：不对称性拴系的力学因素作用下椎体和椎间盘楔形变的构成比在不断演变，为建立稳定的侧凸动物模型，必须达到一定的拴系固定时间以期制造足够的椎体楔形变。

英文摘要:

  【Abstract】 Objectives: To investigate the evolution of the disc and vertebral wedging under unilateral tethering in porcine scoliosis model and its significance. Methods: Seven female pigs underwent posterior asymetric tethering surgery. All pigs underwent serial postero-anterior X-ray films at 4-week intervals to document progression of the deformity. The disc and vertebral wedging in the curve was measured by Cobb′s method. The wedging angle of 5 vertebrae and 4 discs which included apex and 2 ending vertebrae as well as discs between these vertebrae were analyzed. The wedging angle of every disc and vertebra in whole major curve was measured, and the proportion to the Cobb angle was calculated(wedging percentage) respectively. Results: The wedging angle of the vertebra in the apical area increased over time. The wedging angle of the apical vertebra and disc was found larger than that of the adjacent vertebrae. Immediately after operation, the wedging of intervertebral discs contributed to the scoliosis completely. However, the contribution of the vertebral wedging to the scoliosis increased over time. The wedging of the vertebra contributed largely(71.5%) to the scoliosis at 8 weeks postoperatively. Conclusions: The relative contributions of vertebral and disc wedging to the Cobb angle vary over time under asymmetric tethering. To obtain a reliable scoliosis animal model, adequate tethering period is required to get prominent vertebral wedging.