新型蝶形枕颈内固定系统固定的生物力学稳定性研究

Biomechanical stability of a new aliform internal fixation system

中文关键词:  枕颈融合术  寰枢椎脱位  蝶形固定器  生物力学

英文关键词:Occipitocervical fusion  Atlantoaxial dislocation  Aliform fixation device  Biomechanical

中文摘要:

  【摘要】 目的：评价新型蝶形枕颈内固定系统固定的生物力学稳定性。方法：选取6具新鲜冰冻人体枕颈部标本，年龄为20~35岁，男3具，女3具。每具标本解剖截取其C6以上的部位，保留枕骨粗隆以下的颅骨骨性结构及其与颈椎相连的韧带部分，仔细剔除附着于颅脊交界区骨性结构周围的肌肉组织，完整地保留该区域的各种韧带与关节囊，制作为正常模型（N组），用Motion Analysis三维运动测试机测量C0~C3节段的屈伸、侧屈及旋转三维运动范围（ROM）；然后离断寰枢椎间横韧带，制成寰枢椎的失稳模型（UN组），测量C0~C3节段的屈伸、侧屈及旋转三维ROM；再将每具标本进行新型蝶形枕颈系统固定，蝶形枕骨板先后依次以11枚螺钉固定（A组）、以7枚螺钉固定（B组）及以3枚螺钉固定（C组），最后每具标本进行SUMMIT系统固定（D组），每种固定后测量C0~C3节段的屈伸、侧屈及旋转三维ROM。对蝶形枕骨板不同的固定方式与寰枢正常模型、失稳模型及SUMMIT系统固定进行组间比较，比较A、B、C、D组内固定方式中枕颈部的屈伸、侧屈及旋转三维稳定性。结果：在6种不同工况下，A、B、C、D组固定方式稳定性均优于正常组及失稳组，组间比较有统计学差异（P<0.05）。在前屈、后伸、左右侧屈方向上的比较，A、B、C、D四种内固定方式组间无统计学差异（P>0.05）。而在左右旋转方向上，A、B、C、D四种不同固定方式组间比较有统计学差异，其中B、C、D三种内固定方式间的比较无统计学差异（P>0.05），而A组与B、C、D三组间的比较均有统计学差异（P<0.05）。结论：新型蝶形枕颈内固定系统固定与SUMMIT内固定系统固定一样能提供有效的力学固定强度，其中以11枚螺钉固定的新型蝶形枕颈内固定系统固定在旋转稳定性上更优。

英文摘要:

  【Abstract】 Objectives: To evaluate the biomechanical stability of a newly developed aliform internal fixation system. Methods: Six occipitocervical cadaveric specimens of fresh human were chosen, including 3 males and 3 females, aged 20-35 years old. In normal models(group N), bony structures, ligaments and articular capsules ranging from occipital protuberance to C6 were preserved, and the muscular tissue at the craniocervical junction was carefully removed. Then the transverse atlantal ligaments were cut off to make the atlantoaxial dislocation models(group UN). The Motion Analysis was used to measure the C0-C3 ROM in the group N and UN. After that, the cadavers with atlantoaxial dislocation were fixed by the aliform internal fixation system and SUMMIT system. According to different fixation methods, the cadavers were divided into 4 groups: aliform occipital plate with 11 screws fixation in group A, aliform occipital plate with 7 screws fixation in group B, aliform occipital plate with 3 screws fixation in group C, SUMMIT system fixation in group D. The biomechanical stability was compared among the 4 groups in flexion, extension, lateral flexion and rotation. Results: In the six different dimensions, the biomechanical stability of group A, B, C and D was better than that of group N and UN(P<0.05). There was no significant difference of stability among the four fixation methods in flexion, extension and lateral flexion(P>0.05). However, in left and right rotation, a significant difference of stability among the four groups was observed. There was no significant difference of biomechanical stability among group B, C and D, while the biomechanical stability of group A had significant difference with that of group B, C and D. Conclusions: Both the newly developed aliform internal fixation system and the SUMMIT system can eaually provide effective mechanical fixation strength. However, the newly developed aliform occipital plate with 11 screws fixation is better in rotation dimension.