The primary goal of Neurofibromatosis deformity surgery is to stabilize the vertebral column and halt further progression of the deformity rather than perform perfect correction that could result in permanent neurologic sequelae 1).
The relentless progressive nature of dystrophic curves necessitates aggressive operative treatment, which often has a significant toll on the quality of life of affected patients through their early childhood. The bracing of dystrophic curves has been unsuccessful. Combined anterior/posterior spinal arthrodesis including the entire structural component of the deformity is indicated in most cases, particularly in the presence of associated sagittal imbalance. This should be performed using abundant autologous bone graft and segmental posterior instrumentation to minimize the risk of non-union and recurrence of the deformity 2).
If excessive angular kyphosis is present or if the vertebrae are weak due to the bony dysplasia, postoperative orthotic immobilization is recommended even if instrumentation has been successfully applied, in order to remove excessive strains at the proximal hook sites and prevent dislodgement of the instruments 3) 4)
»: Traditional growing rods provide good functional and deformity outcomes in patients with NF and EOS; magnetically controlled growing rods (MCGRs) also provide good deformity correction, although high rates of revision have been reported after their use 5).
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 6).
Halmai et al. reported on a series of 12 patients (11 with dystrophic and one with non dystrophic deformities) who underwent surgical treatment.
In the case of a nondystrophic curve, posterolateral instrumentation-assisted fusion was performed. A curvature correction of 70% was achieved in the frontal plane, and at the 2-year follow-up examination, neither bone dysplasia nor pseudarthrosis was observed. In the cases with dystrophic curves, preoperative traction for 3 weeks was applied; the anterior surgical release was then performed, as was two-stage posterior instrumentation-assisted fusion. In the cases of thoracic kyphoscoliosis in which this treatment protocol was performed, the mean scoliosis correction was 66%, whereas the mean decrease in kyphotic angle was 34.5 degrees. In the cases with thoracolumbar and lumbar curves, the mean correction in the frontal plane was 69.8 degrees, whereas the mean preoperative lumbar kyphosis of 42 degrees was corrected to a mean lordotic angle of 23 degrees. Postoperatively, no hook dislocation was detected. A neurological complication was observed in one case.
The surgical treatment of dystrophic curves always included 360 degrees fusion and the use of a tibial corticocancellous graft, which must be placed on the concave side of the curve in the frontal plane, the graft thereby providing biomechanical support 7).