MATERIAL and METHODS: The computed tomography (CT) images of three groups (Group 1: paediatric cases aged 1-6 years, Group 2: age7-16 years, and Group 3: adult cases), who had cervical spine CT were used to measure some morphometric parameters for safe C2 translaminar screw fixation. The measured parameters included thickness, height and length of the C2 lamina on both sides and the C2 lamina-midline angle.

RESULTS: C2 lamina thickness at the thinnest point on the right and left sides was found to be 4.4 ± 0.5 mm and 4.6 ± 0.5 mm in Group 1, 5.3 ± 0.8 mm and 5.6 ± 0.8 mm in Group 2, and 6.8 ± 1.4 mm and 7.0±1.5 mm in Group 3, respectively (p>0.05). The height of the C2 lamina at the thinnest point on the right and left sides was found to be 5.8 ± 0.8 mm, and 5.8 ± 0.7 mm in Group 1,10.4 ± 1.4 mm and 10.6 ± 1.4 mm in Group 2, and 10.6 ± 1.8 mm, and 10.7 ± 1.5 mm in Group 3, respectively (p>0.05). The mean length of the C2 lamina was found to be 20.6 ± 2.4 mm in Group 1, 31.4 ± 4.1 mm in Group 2, and 36.7 ± 3.3 mm in Group 3 (p<0.05). There was no significant difference between Group 2 and Group 3 in respect of mean lamina angle (44º vs 45º) but it was lower in Group 1 (35º).

CONCLUSION: This study revealed the appropriateness of C2 anatomy for safe C2 translaminar screw fixation. Keywords : C2, C2 translaminar screw fixation, Morphometric analysis