A study of measurement of unpaired and paired parameters of axis vertebra in males

Pathan F J¹, Rubeena Hashmi^2*

Abstract               Background: Axis vertebra (C2) is atypical in its shape and morphological characteristics and forms an integral part of the craniovertebral junction Aims and Objectives: Study of measurement of unpaired and paired parameters of axis vertebra in males. Methodology: This was a cross-sectional study carried out in the apparently normal individuals undergone MRI for neck included into the study over a six month period i.e. January 2018 to June 2018 in the six month period 50 males were included into study. We have done morphometric analysis of Axis Vertebra with respect to Body Axis – AP and Transverse diameter, Ant. height, Post. Height; Dense of axis –AP, Transverse diameter, Vertical height; Vertebral canal–AP and Transverse diameter etc. The paired parameters like Pedicle, Superior articular facet, Inferior articular facet, Lateral mass, Foramina transversarium, Lamina etc. was measured and data entered excel sheets and analyzed by excel software for windows. Result: In our study we have found in males the Body of Axis the Mean±SD in mm - AP diameter was -13.2± 0.42; Transverse was 17.96±0.87; Ant. height was 9.64± 0.38; Post. Height was 9.06± 0.56. In Dense axis it was, AP diameter -7.61 ±0.19, Transverse- 7.60 ± 0.20; Vertical-15.79 ± 0.87; Vertebral canal – AP Was 12.40 ± 0.55, Transverse was 18.64 ± 0.77. The measurement on Lt. and Rt. Respectively of Pedicle -Length was 27.98± 4.12 and 27.87± 3.45 Width was 6.98± 2.87 and 6.54± 3.12 ; Height was 8.78±2.61 and 8.74 ± 3.42 ; Median angle -8.12±1.32 and 8.18± 3.42; Superior articular facet AP-diameter was 16.21±1.65 and 16.31±1.81; Trans. Diameter was 14.63±2.13 and 14.42±1.45; Superior angle of SAF was 78.81±4.35O and 78.62±3.75. Conclusion: It can be concluded from our study that parameters of Axis vertebra on unpaired and paired i.e. Rt. and Lt. side is definitely useful for the diagnosis, surgical management and understanding the pathology cervical neck etc.

Key Word: paired parameters of axis vertebra, unpaired parameters of axis vertebra, Pedicle, Dense, Body of axis vertebra, Morphometry of axis vertebra.

INTRODUCTION

Axis vertebra (C2) is atypical in its shape and morphological characteristics and forms an integral part of the craniovertebral junction^1-3. It has various distinct anatomical features like dens or odontoid process, two lateral masses with obliquely oriented articulating facets, transverse processes with foramina transversarium d spinous process. It is related to various vita and a usually bi structures like the cervico-medullary junction, cranial nerves, cervical spinal nerve roots and vertebral arteries. Various pathological processes like congenital skeletal dysplasias, trauma, infection, neoplasm etc. affect the axis vertebra^2-6 So the details of measurements are necessary and different in males and females for the various surgical procedures at neck so we have done so we have done a Study of measurement of unpaired and paired parameters of axis vertebra in males.

METHODOLOGY

This was a cross-sectional study carried out in the apparently normal individuals undergone MRI for neck included into the study over a six month period i.e. January 2018 to June 2018 in the six month period 50 males were included into study. We have done morphometric analysis of Axis Vertebra with respect to Body Axis – AP and Transverse diameter, Ant. height, Post. Height; Dense of axis –AP, Transverse diameter, Vertical height; Vertebral canal – AP and Transverse diameter etc. The paired parameters like Pedicle, Superior articular facet, Inferior articular facet, Lateral mass, Foramina transversarium, Lamina etc. was measured and data entered excel sheets and analyzed by excel software for windows.

RESULT

Table 1: Morphometric analysis of Axis Vertebra in the male patients (n=50)

 In males the Body of Axis the mean±SD in mm - AP diameter was -13.2± 0.42; Transverse was 17.96±0.87; Ant. height was 9.64± 0.38; Post. Height was 9.06± 0.56. In Dense axis it was, AP diameter -7.61 ±0.19, Transverse- 7.60 ± 0.20; Vertical-15.79 ± 0.87; Vertebral canal – AP Was 12.40 ± 0.55, Transverse was 18.64 ± 0.77

Table 2: Distribution of the paired parameters of pedicle and articular facets(n=50)

The measurement on Lt. and Rt. Respectively of Pedicle -Length was 27.98± 4.12 and 27.87± 3.45 Width was 6.98± 2.87 and 6.54± 3.12 ; Height was 8.78±2.61 and 8.74 ± 3.42 ; Median angle -8.12±1.32 and 8.18± 3.42; Superior articular facet AP-diameter was 16.21±1.65 and 16.31±1.81; Trans. Diameter was 14.63±2.13 and 14.42±1.45; Superior angle of SAF was 78.81±4.35^O and 78.62±3.75 ^O; Inferior articular facet was AP-diameter was 9.56 ±1.42 and 9.75±1.98; Trans. Diameter 9.75±2.12 and 9.85±1.63; Lateral mass was 7.92± 2.36 and 7.86±1.31; Foramina transversarium Height was 6.54±1.65 and 6.47±1.57; Width was 5.32± 1.32 and 5.27± 0.95; Lamina Length was 14.21± 1.25 and 13.54±3.27; Height was 14.01± 1.28 and 12.34±2.58; Thickness was 9.02± 3.12 and 5.69± 1.35

DISCUSSION

Axis, the second cervical vertebra, forms a pivot on which the atlas rotates carrying the head to allow greater range of motion at the atlantoaxial joints^{7, 8}. The lateral masses of axis have good cancellous bone quality beneath the articular surface of facets that makes this area a good site for insertion of an internal fixation device⁹. The elements of pedicle and pedicle axis are critical to the structural anatomy of axis vertebra which are important to normal function and also for cases of pathology or fractures when surgical intervention is required^10,11. The superior articular facets (SAF) of axis differ from other vertebral facets which make this region more prone to vertebral artery injury during screw fixation¹². In axis vertebrae the SAF lies in proximity to the body and medial aspect of the axis of the pedicle whereas SAF of other vertebrae are lying in proximity to the junction of pedicle and lamina and also the vertebral artery foramen is lying partially or completely in the undersurface of axis while in other vertebrae the vertebral artery foramen is located entirely in relation to foramen transversarium^13,14. This unusual location of vertebral artery foramen makes the vertebral artery more prone to injury during screw fixation¹⁵.  In our study we have found in males the Body of Axis the mean±SD in mm - AP diameter was -13.2± 0.42; Transverse was 17.96±0.87; Ant. height was 9.64± 0.38; Post. Height was 9.06± 0.56. In Dense axis it was, AP diameter -7.61 ±0.19, Transverse- 7.60 ± 0.20; Vertical-15.79 ± 0.87; Vertebral canal – AP Was 12.40 ± 0.55, Transverse was 18.64 ± 0.77  The measurement on Lt. and Rt. Respectively of Pedicle -Length was 27.98± 4.12 and 27.87± 3.45  Width was 6.98± 2.87 and 6.54± 3.12 ; Height was 8.78±2.61 and 8.74 ± 3.42 ; Median angle -8.12±1.32 and 8.18± 3.42; Superior articular facet AP-diameter was 16.21±1.65 and 16.31±1.81; Trans. Diameter was 14.63±2.13 and 14.42±1.45; Superior angle of SAF was 78.81±4.35^O and 78.62±3.75 ^O; Inferior articular facet was AP-diameter was 9.56 ±1.42 and 9.75±1.98; Trans. Diameter  9.75±2.12 and 9.85±1.63; Lateral mass was 7.92± 2.36 and 7.86±1.31; Foramina transversarium Height was 6.54±1.65 and 6.47±1.57; Width was 5.32± 1.32 and 5.27± 0.95; Lamina Length was 14.21± 1.25 and 13.54±3.27; Height was 14.01± 1.28 and 12.34±2.58; Thickness was 9.02± 3.12 and 5.69± 1.35  These findings are similar to Shilpa Gosavi¹⁶ et al they found the mean antero posterior diameter of body of axis vertebra was 14.77±1.33mm. The external height of lateral mass on right side was 8.77 ±1.43 mm, 8.28±1.26mm on the left side. The height of dens was 14.86±1.54mm and average transverse diameter was 9.28mm.

CONCLUSION

It can be concluded from our study that parameters of Axis vertebra on unpaired and paired i.e. Rt. and Lt. side is definitely useful for the diagnosis, surgical management and understanding the pathology cervical neck etc.

REFERENCES