A kyphectomy technique with reduced perioperative morbidity for myelomeningocele kyphosis.

STUDY DESIGN: The lumbar sacropelvis in 11 patients with myelomeningocele and kyphosis was treated with a subtraction kyphectomy technique and posterior instrumentation. The results of this procedure in the 11 patients were evaluated and compared with previous results.

OBJECTIVE: To examine critically their experience using the subtraction (decancellation) vertebrectomy technique combined with posterior instrumentation for myelomeningocele kyphosis, the authors reviewed the charts of 18 myelomeningocele patients who underwent surgery for lumbar kyphosis between 1994 and 1998.

SUMMARY OF BACKGROUND: The benefits of restoring sagittal spinal alignment in myelomeningocele patients with severe lumbar kyphosis deformity to achieve postural stability and improved sitting balance generally are accepted. The optimal method of deformity correction, the extent of instrumentation, and the role of limited arthrodesis remain undefined.

METHODS: Of the 18 patients considered, 11 met the inclusion criteria of having undergone reconstruction using a subtraction (decancellation) vertebrectomy technique, preservation of the thecal sac, limited arthrodesis with posterior transpedicular lumbosacral instrumentation, and a minimum follow-up evaluation of 2 years. The study considered the age of the patient, number of levels fused, estimated blood loss, preoperative deformity, immediate postoperative correction, magnitude of correction, and maintenance of correction at latest follow-up assessment.

RESULTS: The average age at the time of the index procedure was 6 years (range, 3-12 years). The average preoperative kyphosis was 88 degrees (range, 50-149 degrees ). Immediately after surgery, the average curve measurement was 3 degrees lordosis (range, 50 degrees to 50 degrees ). The average magnitude of postoperative sagittal plane deformity correction was 91 degrees (range, 43-126 degrees ). Finally, the magnitude of correction maintained at the final follow-up assessment averaged 66 degrees (range, 22-114 degrees ). This represented an average loss of correction at 2 years of 24 degrees (range, 0-84 degrees ). There were no deaths, episodes of acute-onset hydrocephalus, vascular complications, or chronic deep wound infections.

CONCLUSIONS: The subtraction (decancellation) vertebrectomy technique with preservation of the dural sac is a safe and efficacious technique for correction and stabilization of myelomeningocele kyphosis in young patients. Morbidity is reduced, as compared with that of excision techniques. Restoration of sagittal alignment at the time of initial correction and stabilization to achieve a balanced spine led to acceptable results.