Computed tomographic morphometric analysis of the pediatric occipital condyle for occipital condyle screw placement.

Study Design. This study is a computed tomographic (CT)-based morphometric analysis of the pediatric occipital condyles as related to occipital condyle screw placement. Objective. To quantify reference data concerning the dimensions of the immature occipital condyles to guide the placement of occipital condyle screw. Summary of Background Data. To the best of our knowledge, no published study has provided insight into the anatomy of occipital condyle of the pediatric population with different age groups. Methods. Sixty-nine pediatric patients were divided into 4 age groups, and their occipital condyles were studied on CT scans. Condylar length, width, height, sagittal angle, and sagittal angle lengths were measured on Philips Brilliance 16 CT. Results. The mean pediatric coronal height, sagittal length, and axial width noted statistically significant age-related differences were 9.0 mm, 21.3 mm, and 9.8 mm, respectively. The mean sagittal angle for all patients was 27.2 +/- 5.1 degrees (range, 15.1-41.0 degrees). In 82.6% (114/138) of the occipital condyles, the anatomy could accept the occipital condyle screw (width >= 8 mm and height >= 6.5 mm). Conclusion. Our investigation provides insight into the anatomy of occipital condyle of the pediatric population with different age groups. As the pediatric occipital condyles have sufficient occipital bone for appropriate fixation or fusion, the occipital condyle screws fixation is a feasible technique for children. Even so, given the evolution of this technique being still in its infancy and the complexity inherent to the craniovertebral junction, a careful radiological analysis of occipital condyle must be required in preoperative planning and feasibility determination.