Anatomical gender differences in cervical vertebrae of size-matched volunteers

Clinical literature consistently identifies women as more susceptible to trauma-related neck pain, commonly resulting from soft tissue cervical spine injury. Structural gender differences may explain altered response to dynamic loading in women leading to increased soft tissue distortion and greater injury susceptibility.

Identify anatomic gender differences in cervical spinal geometry that contribute to decreased column stability in women.

Previous studies investigating male and female vertebral and vertebral body geometry demonstrated female vertebral dimensions were smaller. However, populations were not size matched and parameters related to biomechanical stability were not reported.

Computed tomography scans of the cervical spine were obtained from size-matched young healthy volunteers. Geometrical dimensions were obtained at the C4 level and analysis of variance determined significant gender differences.

Two volunteer subsets were size matched based on sitting height and head circumference. All geometrical measures were greater in men for both subsets. Vertebral width and disc-facet depth were significantly greater in men. Additionally, segmental support area, combining interfacet width and disc-facet depth, was greater in men, indicating more stable intervertebral coupling.

Present results of decreased linear and areal cervical dimensions leading to decreased column stability may partially explain increased traumatic injury rates in women.