Lamina measurements with computed tomography for c2 translaminar screw fixation in pediatric and adult cases

AIM C2 translaminar fixation has been introduced to decrease the risks associated with C2 pedicle fixation. The aim of this study was to measure C2-related morphometric parameters in a Turkish population. 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±0.5mm and 4.6±0.5mm in Group 1, 5.3±0.8mm and 5.6±0.8 mm in Group 2, and 6.8±1.4mm and 7.0±1.5mm 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±0.8mm, 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±1.8mm, and 10.7±1.5mm in Group 3, respectively(p 0.05). The mean length of the C2 lamina was found to be 20.6±2.4mm in Group 1, 31.4±4.1 mm in Group 2, and 36.7±3.3mm in Group 3 (p 0.05). There was no significant difference between Group 2 and Group 3 in respect of mean lamina angle (44 o 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.