Mahato Niladri Kumar
Department of Anatomy, SRM Medical College and Research Centre, Kattankulathur, Kanchipuram, Tamil Nadu, India.
N Am J Med Sci. 2013 Jun;5(6):357-61. doi: 10.4103/1947-2714.114167.
Lumbo-sacral transitional variations are common in the general population. Structural inadequacies of the terminal lumbar vertebral pars interarticularis (PI) and lamina have often been implicated as important factors for lumbo-sacral instability.
Quantifying dimensions of PI and laminae in terminal lumbar vertebrae associated with lumbosacral transitions and compare them with their normal counterparts.
Fourth lumbar vertebrae in spines involved with complete sacralization of the fifth lumbar (L5) vertebrae and L5 vertebrae associated with lumbosacral accessory articulation were measured for the height, width and thickness of the PI and the laminae on both sides and compared to normal vertebrae.
Dimensions in sacralization associated terminal vertebrae were smaller than the normal. The height of the PI and the widths of laminae were observed to be significantly smaller in terminal lumbar segment in sacralized specimen. Lumbo-sacral accessory articulations demonstrated smaller overall dimensions of several parameters. Lamiane in the last lumbar segment associated with lumbo-sacral transitions demonstrate smaller dimensions compared to the normal ones. Sacralization results in maximum diminution of these parameters.
Smaller PI may predispose spondylolysis and spondylolisthesis at lumbo-sacral junctions associated with transitional variations, and warrant special attention to avoid iatrogenic injuries.
腰骶部移行变异在普通人群中很常见。终末腰椎关节突（PI）和椎板的结构缺陷常被认为是腰骶部不稳定的重要因素。
量化与腰骶部移行相关的终末腰椎的PI和椎板尺寸，并将其与正常对应部位进行比较。
测量第五腰椎（L5）完全骶化的脊柱中的第四腰椎以及与腰骶部副关节相关的L5椎体两侧PI和椎板的高度、宽度和厚度，并与正常椎体进行比较。
骶化相关终末椎体的尺寸小于正常椎体。在骶化标本的终末腰椎节段，观察到PI的高度和椎板的宽度明显较小。腰骶部副关节的几个参数的整体尺寸较小。与腰骶部移行相关的最后腰椎节段的椎板尺寸比正常椎板小。骶化导致这些参数最大程度减小。
较小的PI可能使与移行变异相关的腰骶部连接处易发生椎弓根峡部裂和椎体滑脱，因此需要特别注意以避免医源性损伤。
