Morphometric Analysis of Lumbar Dorsal Root Ganglia: A Cadaveric Study

Background: As there is an increase need for less invasive techniques, especially in the spinal interventional procedures, detailed anatomical structures need to be defined for the better surgical outcome. After an intensive search of the literature, it was found that the available information regarding human lumbar dorsal root ganglia is limited. Therefore, the current study was aimed to analyze the morphometry and location of the dorsal root ganglia in lumbar region. Materials and Methods: One hundred intervertebral foramina from 10 formalin-fixed human cadavers examined from L1 to L5 level. The morphometry of dorsal root ganglia was noted and evaluated. The position of dorsal root ganglia was classified based on its relation to pedicle. Results: The mean length of the dorsal root ganglia was L1, 6.49 mm; L2, 9.63 mm; L3, 12.18 mm; L4, 13.43 mm; L5, 14.95 mm. The mean width was L1, 5.01 mm; L2, 5.96 mm; L3, 6.71 mm; L4, 6.8 mm; L5, 6.83 mm. The mean distance between the dorsal root ganglia and the nerve root was L1, 3.51 mm; L2, 4.03 mm; L3, 5.2 mm; L4, 7.24 mm; L5, 8.46 mm. Most of dorsal root ganglia were intraspinal in L1-L2 intervertebral foramen, intraforaminal in L2-L3 to L4-L5 level and extraforaminal at L5-S1. Conclusion: In-depth knowledge of position of dorsal root ganglia will be helpful in safely performing surgery in the lumbar spinal region.