Morphometric study of the nerve roots around the lateral mass for posterior foraminotomy.
OBJECTIVE
Morphometric data on dorsal cervical anatomy were examined in an effort to protect the nerve root near the lateral mass during posterior foraminotomy.


METHODS
Using 25 adult formalin-fixed cadaveric cervical spines, measurements were taken at the lateral mass from C3 to C7 via a total laminectomy and a medial one-half facetectomy. The morphometric relationship between the nerve roots and structures of the lateral mass was investigated. Results from both genders were compared.


RESULTS
Following the total laminectomy, from C3 to C7, the mean of the vertical distance from the medial point of the facet (MPF) of the lateral mass to the axilla of the root origin was 3.2-4.7 mm. The whole length of the exposed root had a mean of 4.2-5.8 mm. Following a medial one-half facetectomy, from C3 to C7, the mean of the vertical distance to the axilla of the root origin was 2.1-3.4 mm, based on the MPF. Mean vertical distances from the MPF to the medial point of the root that crossed the inferior margin of the intervertebral disc were 1.2-2.7 mm. The mean distance of the exposed root was 8.2-9.0 mm, and the mean angle between the dura and the nerve root was significantly different between males and females, at 53.4-68.4 degrees .


CONCLUSIONS
These data will aid in reducing root injuries during posterior cervical foraminotomy.
Hwang
Jae-Chan
JC
Department of Neurosurgery, College of Medicine, Soonchunhyang University, Seoul, Korea.
Bae
Hak-Geun
HG
Cho
Sung-Won
SW
Cho
Sung-Jin
SJ
Park
Hyung-Ki
HK
Chang
Jae-Chil
JC