四种脊柱固定器的生物力学测试与临床应用

目的通过生物力学测试和临床应用，对四种脊柱内固定器进行评价。方法取24具新鲜猪的胸腰椎脊柱标本，制作最严重前中后柱损伤模型，比较四种不同椎弓根内固定器械在轴向压缩、弯曲和扭转实验的生物力学稳定性及握持能力。178例病例采用统一的半椎板切除，对侧椎板内侧皮质切除扩大椎管，潜行脊髓前方推挤骨片减压，随机分组安装Dick钉、AF钉和池氏钉内固定，一期植骨融合术。术前、术后均摄X片及CT片，分别测量病椎的前缘高度、后缘高度、后凸角度、椎管内径。结果池氏椎弓螺钉抗拔出力，抗侧屈及抗扭转能力较Dick钉、AF钉、RF钉均强(P<0.05)。临床应用178例，其中Dick钉内固定50例，AF钉53例，池氏钉65例。池氏钉后凸矫正率为92.0±20.5％，前缘矫正率为81.3±10.7％后缘矫正率为69.7±8.3％，椎管内径改善率为89.4±15.1％。经统计学处理较Dick、AF均有显著差异。(P<0.05)。结论新型脊柱内固定器(池氏钉)不失为一种较为理想的内固定器械。半椎板切除，对侧椎板内侧皮质切除椎管扩大，潜行脊髓前方减压，不破坏椎弓根和小关节突，保留大部分后柱结构，是一种较为理想的手术方式。

The Biomechanical Studyand Clinical Application of Four Kinds of Spinal Internal Fixators

Objective To evaluate four kinds of spinal internal fixator with the biomechanical study and clinical application. Methods Twenty－ four porcine thorocolumbal spinal fracture model were made to compare the stability of four internal fixators by its axis compression,bending,and rotation.One hundreds and seventy－ eight cases of thoracolumbal fracture were treated with semi－ laminectomy and removal of internal cortex of contra lateral lamina,anterior spinal cord decompression,and fixed with AF,RF,Dick and CYL,respectively.The height of the anterior and posterior range,the angle of kyphosis,the volume of spinal canal were measured with X－ ray and CT examination. Results CYL instrumentation was better than the others in the axis compression,bending,and rotation test(P<0.05).The clinical application of 178 cases(Dick 50 cases,AF 53 cases,CYL system 65 cases)showed that in CYL system,the correction rate of kyphosis was 92.0± 20.5％ ,those of anterior margin and posterior margin were 81.3± 10.7％ and 69.7± 8.3％ ,and the correction rate of spinal canal is 89.4± 15.1％ .It showed prominent differences with that of Dick and AF(p<0.05). Conclusions The new－ designed CYL system is one of the best spinal fixator in treating the thorocolumbal spinal fractures.The semi－ laminectomy with anterior spinal decompression and spinal enlargement is a perfecter surgical method,which remains most posterior column structure without injuried pedicle and articular process.