Pedicle screw implantation in the thoracic and lumbar spine of 1-4-year-old children: evaluating the safety and accuracy by a computer tomography follow-up.

ABSTRACT

STUDY DESIGN: This was a retrospective clinical study. OBJECTIVE: To evaluate the safety and accuracy of pedicle screw placement in very young children and to observe its influence on vertebral and spinal canal growth. SUMMARY OF BACKGROUND DATA Although widely used, it is not known if pedicle screw fixation is safe and effective in very young children. METHODS: Sixteen children, with an average age of 34 months, had received pedicle screw fixation from January 2003 to January 2010. Candidates for surgery were those patients who had hemivertebra deformity (11 patients), eosinophilic granuloma disease with spinal cord compression, and neurological deficit (2 patients), or spinal tuberculosis accompanied with kyphotic deformity (3 patients). The location of involved vertebrae was between T2 and L5. A total of 74 pedicle screws were implanted using a modified free-hand technique. The safety and accuracy of this method, and the influence on vertebral growth, was evaluated using postoperative x-ray and computer tomography scans. RESULT: The average follow-up was 30.6 months. No patient had any neurological or radicular symptoms related to the placement of pedicle screws. Postoperative computer tomography scans demonstrated a malposition of 5 of the 74 pedicle screws (6.8%). Two screws breached the anterolateral cortical bone of the vertebral body. One screw breached the lateral cortical bone of the pedicle, 1 passed through the anterior vertebral margin by 3 threads, and a third was so laterally placed that it entered into disk space. There was no vessel, visceral complications, or any other adverse effects resulting from these misplacements. No screw was placed so medially that injured the spinal cord. No retardation of vertebral growth was observed in 7 patients who were followed up for at least 3 and up to 7 years. CONCLUSIONS: The results indicate that in very young children, pedicle screws can be safely implanted using a modified free-hand implantation technique.