腰骶椎前路同种异体骨垫的设计及其生物力学评价

The design of lumbosacral anterior allograft fusing cage (LAAFC) and the evaluation for its biomechanical properties

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。方法:(1)CT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、最大抗压负荷最大拔出力等方面的生物力学性能。结果:(1)CT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9.03/7.11～13.93/9.73mm。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/矢状径范围是40.51/29.38～46.20/33.98mm。(2)生物力学评价:①三维运动方面骨垫、髂骨及钛网均能增强不稳节段的稳定性,C、D、E、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)。②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。③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)。结论:腰骶椎前路骨垫设计符合腰椎生理解剖,具有足够抗压、抗滑、稳定脊柱节段的生物力学性能。

Objective： To design the lumbosacral allografl fusing cage （LAAFC） and evaluate its biomechanical properties. Methods： （1）The anterior/posterior intervertebral height and anteroposterior/transverse diameter of 33 volunteers without spinal disease were measured via CT scanning, and then LAAFC were designed according to those references. （2） Six human cadaveric lumbar spinal specimens （T12-S2） were divided into six groups： intact FSU（A） ,unstable FSU（B）, FSU with mesh-cage（C）, FSU with LAAFC（D）, FSU with iliac （E）, FSU with iliac and Z-plate system（F）. Mechanical stabilities, including the range of movement （ROM）, the maximum pull-out force and the maximum anti-press force were determined by testing among different groups. Results： （1）The anterior intervertebral height of normal lumbosacral spine was taller than the posterior intervertebral height, with significant difference between them （P〈0.05）. The anterior/posterior intervertebral height ranged from 9.03/7.11 mm to 13.93/9.73 mm. The transverse diameter of normal lumbosacral spine was longer than the anteroposterior diameter, with significant difference between them （P〈0.01 ）. The transverse diameter/anteroposterior diameter ranged from 40.51/29.38mm to 46.20/33.98 mm. （2） LAAFC used alone significantly decreased the Rom at flexion, extension and lateral bending （P〈0.05）, and there were no significant difference between Mesh-cage and LAAFC groups （P〉0.05）; For the maximum pull-out force, there were significant difference among mesh-cage, iliac and LAAFC groups （P〈0.05）. The maximum pull-out force of LAAFC was 240.1 ±6.34 N; The maximum anti-pmss force of LAAFC was about 7515.5±111.0N. There were no significant difference between mesh-cage and LAAFC groups （P〉0.05）, but showed difference when they compared with iliac groups （P〈0.001）. Conclusions： The lumbarsocral anterior allogroft fusing cage can provide enough biomechanical stability after disc excision, and it is suitable to clinical lumbar anterior approach fusion.