Relative Analysis Between Lumbosacral Transitional Vertebra And Lumbar Spinal Stenosis

OBJECTIVE:To investigate the relationship between lumbosacral transitional vertebra and the lumbar spinal stenosis.STUDY DESIGN AND METHODS:This retrospective study involved 60 patients with lumbar spinal stenosis confirmed by surgery.As a control group,61 patients who underwent antedoposterior and lateralⅩ-ray and CT scans of the lumbosacral region because of any reasons were studied.In all cases plain radiological examination and CT scans of the lumbosacral region were obtained to establish the incidence of any type of lumbosacral vertebrae.Then we divided all the patients into another two categories with and without LSTV.All the patients were analysed and compared by parameters including the condition of intervertebral disc degeneration,thickness of ligamenta flava,facet degeneration,lateral spinal canal diameter,central spinal anterioposterior and transverse diameter and lumbosacral angle.RESULTS:23 patients(38.33%)were found with lumbosacral transitional vertebra(LSTV)in 60 lumbar spinal stenosis,which is higher than that of the control group.The typeⅡLSTV of castellvi’s standard is the most common case,the typeⅢandⅣare relatively rare.According to CT scans,there was statistically significant difference in the incidence of disc degeneration and herniation,ligamenta flava pachynsis,facet degeneration and lateral spinal stenosis between the patients with and without lumbosacral transitional vertebra(P＜0.05).No significant difference of the central spinal stenosis was found between the two categories(P＞0.05).In the patients with lumbosacral vertebrae,the level of intervertebral disc degeneration and herniation,ligamenta flava pachynsis,facet degeneration and lateral spinal stenosis occurred more often at the level suprajacent to the lumbosacral transitional vertebra than at the same level in patients without lumbosacral transitional vertebra.And there was no significant difference of these parameters mentioned above in the level of L3/L4 between the two categories(P＞0.05).The average lumbosacral angle measured onⅩ-ray images were 39.14°and 34.86°in the patients with and without lumbosacral transitional vertebra,respectively.The difference was also significant.CONCLUSIONS:There’s a closer relationship between the lumbosacral transitional vertebra and the lumbar spinal stenosis.The lumbosacral transitional vertebra can alter the normal anatomical structure and the biomechanics of weight transfer at affected spinal segments.It can increase the lumbosacral angle,through which weaken the stability of the lower lumbar spine.The lumbosacral transitional vertebra can influence various aspects of the lumbar spinal degeneration including the intervertebra disc degeneration and herniation,ligamenta flava pachynsis,facet degeneration and lateral spinal stenosis.And the location of these degeneration occurred more often at the level suprajacent to the lumbosacral transitional vertebra. But there was no significant difference of the central spinal stenosis between the patients with and without lumbosacral transitional vertebra.So our findings indicate that lumbosacral transitional vertebra constitutes a risk factor for the lumbar spinal stenosis.