Feasibility of atlantal lateral mass and axoid pedicle screw insertion in children younger than 6 years

Abstract

Objective To analyze the feasibility of C1 lateral mass (C1LM) and C2 pedicle (C2P) screw insertion in atlantoaxial fixation surgeries for children younger than 6 years. Methods The computed tomography images of 250 patients (age 2-6 years) were randomly collected and studied. The inner diameter and length for each C1LM and C2P were measured in axial view. Height was measured in sagittal view. Screw choice was considered feasible when a sample maintained an additional 0.5 mm bone cortex at the transverse diameter, length, and height at the same time. Analyses with the Student t test were performed for age, sex, and laterality. The screw choice was evaluated with a feasibility percentage. Results The length and transverse diameter of the whole C1LM in children aged 2-6 years were (21.12±2.94) mm and (7.35±1.41) mm, respectively. The overall C2P length, transverse diameter and height were (19.77±2.92), (5.30±1.02), and (5.39±0.85) mm, respectively. The feasibilities of 3.5 mm diameter screw insertion for atlantoaxial vertebrae at different ages, genders, and side children were above 88.00%, and up to 92.12% or more in children older than 3. Conclusion The use of a 3.5-mm lateral mass and pedicle screw in 2- to 6-year-old children was feasible in the majority of cases. Age, sex, and laterality should all be considered when choosing screw sizes in pediatric upper cervical surgeries. Key words: Atlantoaxial; C1 Lateral Mass; C2 Pedicle; Tomographic Study