Study design: Retrospective radiograph and chart review.

Objectives: To assess the safety, efficacy, and complications after posterior spinal arthrodesis with instrumentation for thoracolumbar kyphosis in the pediatric achondroplast.

Summary of background data: The conventional approach of anterior and posterior arthrodesis has achieved minimal correction, avoided instrumentation, and had a high risk of neurologic deterioration. To the current authors' knowledge, there are only two reports of successful instrumentation with pedicle screw fixation for kyphosis in pediatric achondroplasts; the outcome of such procedures remains largely unknown.

Methods: The current authors evaluated the results of posterior spinal arthrodeses with instrumentation performed between 1998 and 2001 on 12 consecutive patients (mean age, 12 years). Indications for arthrodesis were concomitant laminectomy for neurologic symptoms or progressive deformity. Arthrodesis methods included anterior and posterior arthrodesis (5 patients) and posterior arthrodesis only (7 patients). Intraoperative somatosensory-evoked potentials, pedicle screw stimulation, and/or a wake-up test were used to confirm neurologic status in all patients.

Results: Successful fusion was obtained in all patients. No intraoperative or postoperative neurologic deterioration was encountered. Mean improvement in kyphotic deformity was 50%. Complications included three instrumentation fractures (2 patients) and one dural leak. Parents rated outcome as excellent (4), good (6), and fair (2). No patients have subsequently experienced deformity progression.

Conclusions: Spinal arthrodesis with vertebral body and/or pedicle screw instrumentation was a reliable technique for treating thoracolumbar kyphosis in achondroplasia and did not precipitate any of the neuromonitoring difficulties or neurologic deficits that have been reported in previous studies.