Osteometric Dimensions of the Laminas of the Spine

The present study was undertaken to evaluate the dimensions of the laminas from C2 to L5 by using adult human spine specimens for the objective of providing a set of quantitative data for the laminas from C2 to L5 vertebrae.There exists enormous amount of Anatomic data based on facet and pedicle parameters by different research workers, but it seems that the detailed studies based on measurements of laminar parameters from cervical to lumbar spines are almost nil.Forty spines (920 vertebrae) were considered for the present study. Anatomic evaluation of the laminas'included the laminar height, width, thickness, width angle & slope angle.The greatest laminar height was observed at T11 for males & females ( 22.8 ± 2.1 mm, 23.0 + 1.8mm) respectively. There was a marked change in pattern at L5 where there was a decrease in laminar height from that of preceding lumbar levels.The greatest laminar width was at-L5 for males & females (12.1 ± 2.4mm 11.5 ± 2.1 mm ) respectively. The laminar thickness was maximum at T3 for males and females (5:2 ± 0.7mm & 5.1 ± 0.2mm ) respectively. The maximum width angle was at T9 for males (99.2 ± 9.7mm) & at L4for females (100.6 ± 12.3mm). The-slope angle was maximum at L5 for males and females (113.5 ± 4.8mm & 118.0 ± 1.4mm) respectively.Thus, for the proper, understanding of the weight transmission through the spine and it related hypothesis the Anatomic parameters of the laminas provided by the present study are very important and also they provide an adequate database necessary for the surgical placement of sublaminar instruments in spine related surgeries.