Parameters Measurement Of The Cervical Spine X-ray And Significance For Disc Prosthesis Designation

Objective:Through the measurement and statistical analysis of a number of anatomical parameters of cervical spine lateral X-ray, to understand the variations and differences in different cervical segments, and provide theoretical data for cervical artificial disc prosthesis designation. Method:Forty cases of health checkup outpatients were selected to erect a neutral position of cervical spine lateral X-ray in the hospital. For all the cases, vertebral midsagittal length and the central height, the anterior, middle and posterior heights of each intervertebral space, the sagittal length of vertebral body endplates, the vertebral body endplate angle, endplate radius of curvature and the vertebral-upper-facet angles were measured in the Imaging workstation platforms. The measurement of length was accurated to0.01mm and the angle to0.1°. All the parameters data were analyzed statistically.Results:1. Vertebral midsagittal length:the C7>C6>C3>C4>C5. There are statistically significant differences between the C3, C4, C5, and C7, and no difference between others vertebral body.2. Vertebral central height:the C7>C3>C4>C5>C6. There are statistically significant differences between the C3, C4, C5, C6and C7, and no difference between others vertebral body.3. The heights of intervertebral space:The central height of each space> anterior height> posterior height, and the difference is statistically significant. For the central heights of every space, there are no statistically significant differences between the C2/3, C3/4, C4/5, C5/6, but significant differences exist between these four spaces and C6/7.4. The sagittal length of vertebral body endplates:For the same intervertebral space, the sagittal length of upper endplate>lower endplate, but the difference is not statistically significant. For the same vertebral body, the sagittal length of lower endplate>upper endplate, and the differences are statistically significant.5. Endplate angle of vertebral body:Both the upper and lower endplate angles take in descending order from C2to C7. Apart from the C2/3segment, other segments, including C3/4, C4/5, C5/6, C6/7, the endplate angle of lower endplate> upper endplate, and the differences are statistically significant. For the same vertebral body, the angle of upper endplate> the lower one, and the differences are statistically significant.6. Endplate radius of curvature:Both the upper and lower endplate radius of curvature ascending respectively from C2to C7. For the same intervertebral space, the curvature radius of lower endplate> the upper one, and the differences are statistically significant. For the same vertebral body, the radius of upper endplate> the lower one, and the differences are significant.7. The vertebral-upper-facet angle:The angles take on U-shaped distribution, the C7>C3>C6>C4>C5. When the angle of C7is compared with C3, C4, C5and C6, there are statistically significant differences.Conclusion:Trough the measurement of a number of anatomical data in cervical lateral X-ray, the trends and differences of the different segments of anatomic parameters are understood. And then the information provide some theoretical reference for the designation of cervical artificial disc prosthesis, including diameter, height, the shape and curvature of endplate and the shape of prosthesis, so that the prosthesis could better able to restore disc space height, match well with the endplate. All these things can better scatter stress, reduce or avoid a variety of late complications after prosthesis implantation, and improve the clinical efficacy of the cervical artificial disc replacement.