Surgical challenges and functional outcomes in dystrophic cervical kyphosis in Neurofibromatosis -1: an institutional experience.

Objective: Dystrophic cervical kyphosis secondary to neurofibromatosis 1 (NF1) is rarely reported. The primary objective is to highlight the clinical presentation and surgical outcomes based on clinical and biomechanical parameters. The secondary objective is to highlight the early and late complications of these surgeries.

Methods: The hospital records of six patients operated between 2008 and 2018 were retrospectively reviewed with a minimum follow-up of 24 months. Besides demographics information, radiological findings and operative details, the outcome measures reported were neurological (MJOA score, Nurick scale), pain (VAS score) and operative complications.

Results: The mean age of patients was 15.1 years (8-32 years). The average kyphotic vertebra involved-3.6 bodies (range 2-5 bodies) with four patients showing intraspinal anomaly-neurofibromas, dural ectasia. Clinically, patients improved postoperatively with-VAS (pre vs. post-: 6.6 vs. 2.6, p - < 0.05), MJOA score (pre vs. post: 10.3 vs. 13.3, p - < 0.05), Nurick grade (pre vs. post: 3.5 vs. 2.1, p - < 0.05). There was significant deformity correction from 66.8° to 20.7° (p value < 0.031), mean T1 Slope (pre vs. post - 1.8 ± 20.4 to 0.6 ± 12.8, p value - < 0.43). Mean blood loss encountered was 1800 ± 434.6 cc; however, patients with paraspinal neurofibromas reported greater blood loss. Late complications included pseudoarthrosis (1), C5 palsy (1) and junctional kyphosis (1). Vertebral dysplasia and erosions continued in all patients post-operatively.

Conclusions: Antero-posterior approach provides circumferential decompression and better sagittal balance correction. Cervical spine must be screened in all NF-1 patients and followed up regularly to assess for dystrophic changes.