Treatment of dystrophic scoliosis in neurofibromatosis Type 1 with one-stage posterior pedicle screw technique

Abstract

Background context

Corrective surgery for dystrophic scoliosis in neurofibromatosis Type 1 (NF-1) is challenging. There are various surgical methods, all with unsatisfactory outcomes.

Purpose

The purpose of the study was to evaluate the clinical outcomes of the treatment of dystrophic scoliosis in NF-1 with one-stage posterior pedicle screw approach.

Study design

This is a retrospective clinical study.

Patient sample

Sixteen patients with dystrophic scoliosis in NF-1 underwent one-stage posterior surgery with pedicle screw system.

Outcome measurement

We used preoperative and postoperative whole-spine radiographs to determine coronal and sagittal Cobb angles (curve correction); distance between apex vertebra and central sacral vertical line (DAC), pelvic obliquity, and shoulder tilt (coronal balance improvement); and sagittal vertical axis and pelvic tilt angle (sagittal balance improvement). We assessed the fusion rate using fusion segment computed tomography scan.

Methods

Patients underwent surgery with or without osteotomy according to spinal flexibility. Fusion segment selection method of fusion segments selection which mean fusing from one or two levels proximal to upper end vertebra to one or two levels distal to the lower end vertebra (EV+1 or 2) or stable vertebrae fusion. There were no study-specific conflict of interest–associated biases.

Results

The average follow-up time was 40.9 months. Mean scoliosis and kyphosis improved from 83.2° to 27.6° and 58.5° to 26.8°, respectively; at the last follow-up, it was 30.4° and 27.4°, respectively. Mean DAC, pelvic obliquity, and shoulder tilt improved from 53.0 to 23.9, 8.1 to 4.9, and 9.8 to 7.5 mm, respectively. Sagittal vertical axis and pelvic tilt angle improved from −5.8 to 1.6 mm and 17.9° to −5.8°, respectively. During follow-up, mean coronal and sagittal correction losses were 2.8° and 0.7°, respectively. Two EV+1 or 2 patients had decompensation. No pseudoarthrosis was identified.

Conclusions

The one-stage posterior pedicle screw approach is safe and effective in the treatment of dystrophic scoliosis in NF-1. Posterior vertebral column resection is recommended if flexibility is less than 35%. Stable vertebrae fusing is recommended.