与后路腰椎椎间融合器融合术相关的解剖学和影像学研究

The anatomical and radiographic studies of posterior lumbar interbody fusion using cages

目的:测量与后路腰椎椎间融合器融合术(PLIF)相关的解剖学和影像学参数,以规范及改进手术方法。方法:(1)L3～L5干燥标本各20个,测量椎体两侧下关节突内、中、外之间的距离及椎体旁矢状径、椎弓根内距离。(2)从210个椎间隙选择MRI检查正常的L3/4～L5/S1间隙,测量下关节突内、中、外距及椎体旁矢状径、椎间隙高度、椎间隙角度。(3)假设采用宽度7mm、9mm、11mm,长度22mm、24mmcage从后侧置入,间距4mm且cage轴线距离小于椎弓根内距、cage陷入椎体后缘3mm,计算符合上述要求的数值并与两种测量结果比较。结果:解剖学与影像学测量的关节突内、中、外距离无显著性差异。当cage宽度为7mm,L3/4～L5/S1各有64.8%、94.8%、100%可保留完整关节突,9mm时则有12.7%、53.4%、96.3%可保留完整关节突,但均可保留1/2关节突;宽度为11mm分别有0、5.2%、18.5%可保留完整关节突,47.9%、84.5%、100%可保留1/2关节突;3个节段均不必切除全关节突,cage轴线距离小于椎弓根内距;椎体旁矢状径大于22mm、24mm长度cage置入要求的分别为91.2%、86.9%;结论:宽度7～11mm,长度22mm、24mm的立方体形cage适宜国人解剖特点,大多数可保留1/2关节突,以维持节段稳定,恢复椎间高度,增加融合面积。

Objective：To investigate some correlated data with posterior lumbar cage interbody fusion（cage- PLIF） in order to standardize and improve surgical procedure theoretically.Method： （1）Twenty normal dry cadaveric lumbar vertebra specimens were chosen to measure the inner,mid and outer interfacetal distances of inferior facet processes of L3-L5 as well as parasaggital vertebral diameters and pedicle internal distances respectively.（2）210 L3/4-L5/S1 normal intervertebral spaces were selected in MRI scans.The measurements included three interfacetal distances and parasaggital vertebral diameters mentioned above heights of intervertbral disc and intervertebral angle were measured as well.（3）The requirement of implanted cages were as followed： the size of the cage were 7mm/9mm/11mm width,22mm/24mm length,two cages were inserted parallelly,3mm deeper than the posterior edge of the vertebra,the distance between two cages was 4 mm,axis of the cages should not exceed medial surface of pedicles.Compared this required data with the data having procured.All data entered SPSS 10.0 for data processing.Result：The results of interfacetal distances with two measurements were proximate statistically.Intact zygapophysial joints would be preserved in 64.8% of L3/4 5.2% of L4/5 and 100% of L5/S1 if 7mm width cages being used.To 9mm width cages,it would be 12.7%,53.4% and 96.3% accordingly.Half zygapophysial joints could be preserved in three levels no matter either size of cage being used.If 11 mm width cage being inserted no intact zygapophysial joints could be preserved in L3/4,but 5.2% of L4/5,and 18.5% of L5/S1 in which intact zygapophysial joints could be preserved.Half zygapophysial joints would be preserved in 47.9%,84.5% and 100% of 3 levels.The zygapophysial joints would be unnecessary resected totally in three levels no matter either size of cage being used.The distance between the axial lines of two cages was less than inner distances of pedicles.Parasaggital vertebral diameters greater than required saggital length for 22mm/24mm length cages implantation was 91.2% and 86.9% in three levels.Conclusion：The cages with 7mm/9mm/11mm width are suitable to Chinese anatomy with which at least half zygapophysial joints can be preserved in most Chinese patients.Resection for zygapophysial joints should be decreased interoperatively in order to maintain segmental stability,restore intervertebral space height and promote interbody fusion.