颈椎前路减压植骨界面间螺钉固定的实验研究和临床应用

Biomechanical Study and Clinical Application of Interference Screw Fixation

目的 比较单纯植骨、皮质骨螺钉与松质骨螺钉界面间固定的稳定性，并报告临床应用结果。方法 自行设计和制作松质骨螺钉在新鲜颈椎标本间盘切除及椎体部分切除的Ｓｍｉｔｈ－ Ｒｏｂｉｎｓｏｎ 法和Ｂａｉｌｅｙ 法植骨模型中，应用ＷＤ－ １ＯＥ万能电子试验机测试有无界面钉固定的拔出载荷。临床应用２０ 例中男１６ 例，女４ 例；平均４３ ．４ 岁。颈椎骨折脱位１３ 例均为不稳定型。颈椎病７ 例为脊髓混合型。结果 间盘切除模型中，单纯植骨的Ｂａｉｌｅｙ 法［（７７．４ ±１４）Ｎ］ 较Ｓｍｉｔｈ－Ｒｏｂｉｎｓｏｎ 法［（６２．６±２６．７）Ｎ］稳定（Ｐ＞ ０．０５）。皮质骨螺钉与单纯植骨相比，拔出载荷均增加，分别为（ ８８．９±２４ ）Ｎ和（８８．１±１６．６）Ｎ（ Ｐ＞ ０．０５） 。松质骨螺钉拔出载荷分别为（１４４．９±３８．４）Ｎ和（１４４．６±３３．７）Ｎ，比前两种均明显增大（Ｐ＜ ０．０５）。椎体切除模型的结果相近似。１６ 例平均随访１ 年８ 个月，无一例植骨块滑脱及螺钉松动，植骨愈合时间平均１２ 周，症状均有明显好转。３ 例术后不足３ 个月，１ 例失访。结论 界面间松质骨螺钉固定，能有效地稳定植骨块，是一种侧凸面小。

objective The study was conducted to compare the stability of the bone graft fixed by interference cortical screw with interference cancellous screw. The clinical application of the interference screw was also reported. Methods The bone graft was implanted in the cadaver cervical spines with Smith-Robinson and Bailey method in the biomechanical study. The bone graft with Smith-Robinson and Bailey method was fixed by interference cancellous screw, interference cortical screw, or without any instrument. The pull-out strength of the bone graft fixed by different methods was tested. The anterior bone grafts of 20 cases of cervical fracture/dislocation (13 cases) and cervical spondylotic myelopathy (7 cases) were also used in the clinical study. Results The pull-out forces of bone graft with Smith-Robinson and Bailey method were 77.4 ± 14.0 N and 62.6±26.7 N respectively ( P <0.05). The pull-out forces of the bone grafts with cortical screws were 88.9 ±24.0 N and 88.1 ± 16.6 N for Smith-Robinson and Bailey medthod respectively ( P <0.05). The pull-out forces of the bone graft fixed with cancellous screw was 114.9±38.4 N and 144.6±33.7 N respectively, which were significantly greater than that fixed with cortical screw, or without fixation ( P < 0.05 ). The results were similar for both types. In clinical application, all cases achieved solid fusion within the average time of 12 weeks. No graft or screw dislodgement was found. Conclusions The study demonstrates that the interference screw fixation can increase the bone graft stability and decrease the graft dislodgement, and it is simple and effective.