腰骶椎前路同种异体骨垫的设计及其初步临床应用

Design of lumbosacral anterior allograft fusing cage and its early clinical application

目的研制出腰骶椎前路同种异体骨垫并评价其生物力学性能和初步临床疗效.方法①CT测量：通过CT扫描测量33名正常人腰骶椎各椎间隙的前后点高度、腰骶椎的矢、冠状径,为设计出同种异体骨垫提供解剖学依据.②生物力学试验：将设计出的骨垫与钛网、自体髂骨对比,评价它们在三维运动范围、最大拔出力、最大抗压负荷等方面的生物力学性能.③临床初步应用：在临床工作中选择合适病例5例,应用骨垫前路融合技术评价其初步临床疗效.结果①CT测量结果：正常腰骶椎椎间隙前高大于后高,两者之间存在显著性差异（P＜0.05）.前/后高范围（9.03/7.11～13.93/9.73）mm.正常腰骶椎横径大于矢状径,两者之间存在非常显著性差异（P＜0.01）,横径/矢状径范围是（40.51/29.38～46.20/33.98）mm.②生物力学评价：A、三维运动方面：骨垫、髂骨及钛网均能增强不稳节段的稳定性,C组、D组、E组、F组分别与B组比较,都存在显著性差异（P＜0.01）;但骨垫与钛网相比,两者的稳定性无明显差异（P＞0.05）;而与髂骨相比,骨垫更能增强脊柱稳定性,存在显著性统计学差异（P＜0.01）.B、最大拔出力方面：骨垫、髂骨及钛网等三者之间均存在显著性差异（P＜0.05）,髂骨＜骨垫＜钛网.C、最大抗压负荷方面：骨垫、钛网两者之间无显著性差异（P＞0.05）,而与髂骨比较均存在非常显著性差异（P＜0.01）.③临床疗效评价：本组病例均在随访之中,中、晚期疗效有待进一步观察评价.近期疗效根据Steffee方法评定临床结果.本组优3例,良2例,所有病例腰腿痛明显缓解或消失.术后X线片示其病变椎间隙高度恢复.结论腰骶椎前路骨垫设计符合腰椎生理解剖,短期内已具有足够抗压、抗滑、稳定脊柱节段的生物力学性能;其临床应用操作简单安全,恢复椎间隙高度好,融合后无异物遗留等优点.

Objective To design the lumbosacral anterior allograft fusing cage （LAAFC） and to evaluate its biomechanical properties and early clinical outcome. Methods ① Measuring on CT scans： The anterior/posterior intervertebral heights and anterroposterior/trausverse diameters of lumbosacral spine in 33 normal cases who had routine physical examination were measured on CT scans so as to design the LAAFC. ②Biomechanical test： To compare LAAFC to titanium cage and auto-ilium and to evaluate their biomecbenical properties in 3D range of motion（ROM）, maximum snti-press force and maximum poll-out force. ③ Early clinical application： to evaluate the early clinical outcome by using LAAF in five suitablecases with anterior fusing technique, Results ① Measurements on CT scans： The anterior intervertebral beights of normal lumbosacral spine were higher than the posterior, and there were significant differences between them （P〈0.05） The ariterior/posterior intervertebral heights ranged from 9.03/7. 11mm to 13.93/9.73mm. The transverse diameters of normal lumbosacral spine were longer than the ontoroposterior, and there were significant differences between them （P〈0.01 ）. The transverae anteroposteriordiametersrauged from40.51/29.38mm to 46.20/33.98mm. ② Biomechanical resuits： A 3D-ROM： LAAFC, autoilium sad fitsaium cage all could enhance the stability of unstable segment. There were significant differences when comparing Group B to Group C, D, E and F（P〈0.01）. But there was no significant difference in the stability wheal LAAFC was compined to titanium cage（P〉0.05）. when compared to auto-ilium, LAAFC could enhance the stability of spine much better, ao there were significant differences between them （P〈0.01）. B The maximum pull-out force： There were significant differenoces among LAAFC, auto-ilium and titanium cage （ P〈0.05 ）, and the result was that： auto-ilium 〈 LAAFC 〈 titanium cage. C The maximum anti-press force： There was no significant difference between LAAFC and titanium cage（ P〉0.05）, but there were significant differences between LAAFC and auto-ilium （P〈0.01 ）. ③ Clinical outcome： All the cases were in the follow-up, so the effect at advanced stage needed further observation and evaluation. According to Steffce System, early clinical outcome was that ： 3 cases were good and 2 were fine. The backlag pain of all the cases was obviously relieved or disappeared. Postoperative X-ray films showed that the affected intervertebral height was recovered. Conclusion The design of LAAFC is correspond to the anatomy of lumbar spine, which has many biomechanical properties such as sufficient anti-press, anti-slip, stabilizing spinal segments and so on. The procedure for clinical application is simple and safe, which has the advantages such as recovering intervertebral height, no foreign object left after fusing and so on.