Surgical Treatment of the Intraspinal Rib Head Dislocation in Children With Dystrophic Scoliosis Secondary to Type 1 Neurofibromatosis

Abstract

Background: The purpose of this study was to explore the surgical treatment of intraspinal rib head dislocation (IRH) in children with dystrophic scoliosis secondary to type 1 neurofibromatosis (NF1-DS).

Methods: From 2006 to 2019, 32 of 128 patients with NF1-DS were found to have IRH and enrolled in this study. There were 19 boys and 13 girls with an average age of 8.8±2.6 years. Patients were divided into 2 groups: group A (n=25) without IRH resection and group B (n=7) with IRH resection. The intraspinal rib proportion (IRP), apical vertebra rotation, apical vertebral translation, main thoracic curve Cobb angle, trunk shift and thoracic kyphosis, lumbar lordosis, and sagittal vertebral axis were measured before and after the operation. Spinal injury was graded based on the American Spinal Injury Association (ASIA) Impairment Scale.

Results: The study group had a total of 42 IRH. The mean follow-up duration was 46.1±28.7 months. The preoperative IRP in both groups was similar (35.5±14.3% vs. 31.2±15.3%, P=0.522). The postoperative IRP was lower in group B (18.5±11.2% vs. 0%, P=0.002). The IRP in group A decreased from preoperative (31.2±15.3%) to postoperative (18.5±11.2%) (P<0.05). There was no significant difference in the apical vertebra rotation, apical vertebral translation, main thoracic curve Cobb angle, trunk shift, thoracic kyphosis, lumbar lordosis, and sagittal vertebral axis between the 2 groups before surgery and after surgery. Four patients with nerve injury caused by the IRH had full neurological recovery postoperatively. All patients were ASIA grade E at the last follow-up.

Conclusions: The surgical treatment of IRH in children with NF1-DS should be determined on the basis of the presence of preoperative neurological symptoms. This study supports the practice of correcting spinal deformities only in patients with mild or no spinal cord injury. If there are obvious neurological symptoms, IRH resection is necessary to relieve spinal cord compression to recover nerve function.

Level of evidence: Level III.