Surgical Treatment of Dystrophic Spinal Curves Caused by Neurofibromatosis Type 1: A Retrospective Study of 26 Patients

Abstract

Dystrophic scoliosis in neurofibromatosis type 1 (NF-1) is difficult to treat. The purpose of this study was to review the clinical and radiological outcome of surgical treatment of dystrophic spinal curves in NF-1, for analyzing its efficacy, safety, and possible complications.This retrospective study consisted of 26 NF-1 patients with spinal deformities treated between 2003 and 2012 in our department. Preoperative X-ray, 3D-CT, and MRI were performed to evaluate the deformities of dystrophic scoliosis accurately. All patients were treated with posterior instrumented fusion alone using screws and hooks. According to the anatomical development situation of each patient's pedicles and the transverse processes, we chose different fixations and different fixed segments. The clinical and radiological outcomes of surgical correction were evaluated postoperatively.The average preoperative kyphosis was 43° (range 15-86°). The postoperative kyphosis had an average of 20° (range 10-39°) yielding 53% correction. At final follow-up, there was an average of 4.6% correction loss. The preoperative scoliosis Cobb angle had an average of 47° (range 35-96°). The postoperative scoliosis Cobb angle had an average of 21° (range 10-37°) yielding 55% correction. At final follow-up, there was an average of 6.6% correction loss. The apical vertebral body rotation was corrected by an average of 48%. At final follow-up, the score of the SRS-30 questionnaire ranged from 97 to 135 with an average of 109.In conclusion, the deformities of dystrophic scoliosis can be accurately determine through preoperative radiolographic evaluation, which plays an important role in guiding the correction of scoliosis program development. The results of this study demonstrate that satisfactory therapeutic effects can be achieved in the dystrophic scoliosis patients by preoperative meticulous surgical plans, intraoperative careful manipulation, and hybrid instrumentation.

FIGURE 1

Accurately determine the deformities of dystrophic scoliosis preoperatively through X ray (A), 3D-CT (B), and MRI (C).

FIGURE 2

(A) Preoperative 3D-CT showed the intracanal portion of dislocated rib head; (B) postoperative 3D-CT showed that the intracanal rib head has removed completely; the spinal canal was very broad and smooth.

FIGURE 3

A 9-year-old male with a dystrophic curve preoperative and follow-up AP X-rays (A) and 3D-CT (E) revealing a 36° scoliosis corrected down to 11° (C and G). Preoperative and follow-up lateral X-rays (B) and 3D-CT (F) revealing a 60° thoracic hypokyphosis corrected to 18° (D and H). Preoperative (I and J) and 2-year follow-up (K and L) photographs.