Morphometrical study of uncinate processes and vertebral body of cervical spine

Abstract

Objective: The anatomical knowledge is the most important and has a direct link with success of operation in cervical spine surgery. The authors measured various cervical parameters in cadaveric dry bones and compared with previous reported results.

Methods: We made 255 dry bones age from 19 to 72 years (mean, 42.3 years) that were obtained from 51 subjects in 100 subjects who donated their bodies. All measurements from C3-C7 levels were made using digital vernier calipers, standard goniometer, and self-made fix tool for two different cervical axes (canal and disc setting). We classified into 4 groups (uncinate process, vertebral body, lamina, and pedicle) and measured independently by two neurosurgeons for 28 parameters.

Results: We analyzed 23970 measurements by mean value and standard deviations. In comparing with previous literatures, there are some different results. The mean values for uncinate process (UP) width ranged from 5.5 mm at C4 and 5 to 6.3 mm at C3 and C7 in men. Also, in women, the mean values for UP width ranged from 5.5 mm at C5 to 6.3 mm at C7. C7 was widest and C5 was most narrow than other levels. The antero-posterior length of UP tended to increase gradually from C3 to C6. The tip way, tip distance, and base distance of UP also showed increasing pattern from C3 to C7.

Conclusion: These measurements can provide the spinal surgeons with a starting point to address bony architectures surrounding targeted soft tissues for safeguard against unintended damages during cervical operation.

Keywords: Cervical vertebra; Dry bone; Parameters; Uncinate process.

Fig. 1

The self-made fix tools which authors made and used. Anterior (A), lateral (B), and oblique (C) aspect applied with vernier calipers. Schematic sagittal figures of two different axes for cervical vertebra. Canal setting (D) is the state when imaginary longitudinal line made by posterior side of vertebral body is perpendicular to the ground. Disc setting (E) is the state when imaginary horizontal line made by superior side of vertebral body (endplate) is parallel to the ground.

Fig. 2

Schematic figures of parameters of cervical vertebra. Superior (A), enlarged figure of anterior with imaginary line of vertebral artery (B), anterior (C), and sagittal cross section of lateral aspect (D). Illustration (A) from The Textbook of Spine, Korea, 2004, p.37, with permission.