Guideline for C1 Lateral Mass and C2 Pedicle Screw Choices in Children Younger Than 6 Years.

Abstract

Prospective study. To analyze the most feasible choice of C1 lateral mass (C1LM) and C2 pedicle (C2P) screw in upper cervical surgeries for children younger than 6 years. The C1LM and C2P screw technique is a stable cervical vertebrae internal fixation method in upper cervical surgery. Some tomographic studies have indicated the feasibility of insertion of C1LM and C2P screws in children. Their results, however, varied widely, and no consensus was achieved regarding C1LM and C2P screw choices for different ages in the pediatric population, sex, and laterality. The computed tomography images of 250 patients (age 2-6 yr) were 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 inner 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. Statistical differences were found between different ages, sex, and laterality for C1LM length (P < 0.001) and C2P length (P < 0.001). Screws of different sizes were recommended for each age group, sex, and laterality, with a feasibility percentage. 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. This information can be particularly helpful for preoperative planning for C1-C2 internal fixation. 3.