Deterioration of operative correction in dystrophic spinal neurofibromatosis

Of 28 patients with dystrophic spinal deformity resulting from neurofibromatosis who were treated surgically since 1968, 25 were studied regarding the outcome of spinal deformity at a mean follow-up of 9.7 years after surgery (mean age at follow-up, 21.5 years).

This study sought factors that contribute to curve deterioration despite successful spinal fusion for dystrophic spinal deformity in patients with neurofibromatosis. SUMMARY OF BACKGROUND DATA/METHODS: All patients had the following radiographs: standing anteroposterior and lateral, lateral bending, flexion and extension views of the spine, and radiographs of both tibiae. Patients who had large peripheral neurofibromata or evidence of long-bone deformity at other sites had radiographs of these anatomic regions. Spinal radiographs obtained pre-operatively, 6-12 months post-operatively, and at final follow-up were measured for spinal curvatures, vertebral height, and vertebral and disc wedging.

For analysis, the patients were divided into three groups according to deformity: 1) scoliosis, 2) ky-phoscoliosis (with kyphosis > 50 degrees) and 3) hyperkyphosis (with kyphosis > 50 degrees and sharply angulated over three vertebrae). Mean deterioration was: scoliotic group, 12 degrees (range, 0 degree-52 degrees); kyphoscoliotic group, 7 degrees (range, 0 degree-35 degrees); hyperkyphosis group, 38 degrees (range, 20 degrees-60 degrees). All patients in the latter group had anterior and posterior spinal fusion.

Spinal deformity in these patients tended to progress despite the achievement of spine arthrodesis in those with hyperkyphosis and short curves. The study shows that vertebral subluxation, disc wedging, and peripheral skeletal dystrophy are additional prognostic features that predict the progression of deformity after arthrodesis of the spine.