Outcomes of spinal cord injury following cervical fracture in ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis (DISH): A prospective cohort study

Abstract

Introduction: The ankylosed spine is prone to increased fractures risk even after minor trauma. The lower cervical spine is most frequently injured, and fractures of the ankylosed spine tend to precipitate spinal cord injury (SCI). The objective of the current study is to assess the incidence, management, and outcomes of patients with ankylosis of the spine sustaining a cervical fracture with associated SCI over a 7-year period.

Material and methods: Prospective cohort study. Patients referred to the institution with a cervical fracture associated with SCI on a background of AS or DISH from 2009 to 2017 were reviewed. Demographics, mechanism of injury, fracture type, neurological level of injury, time to surgery, surgical management, neurological status (AIS), spinal cord independence measure (SCIMIII) scale at admission and discharge, and hospital length of stay. In September 2019 the summative data was analyzed using NDI, VAS, SV-QLI/SCI and length of survival were analyzed for statistical significance. Pathological fractures and dementia were excluded.

Results: 1613 patients with traumatic SCI were admitted in this period of whom 37 (12 AS and 25 DISH) met the inclusion criteria (mean age 65 years AS; 67 DISH). Fracture-dislocation was the most frequent fracture type (33% AS patients, 24% DISH patients). C4 was the most common neurological level of injury. SCIMIII score at admission was 1 point and 59 at discharge. AIS at admission was A (50%). At time of discharge no patient had neurologically deteriorated. Post-discharge mortality was 58% in AS patients and 32% in DISH patients (p=0.13).

Conclusions: Both AS and DISH patients have high levels of disability and mortality associated with trauma to the cervical spine. Despite their distinct clinical differences, in this cohort there were no statistically significant differences between AS and DISH patients regarding fracture type, SCIMIII, AIS, hospital stay, mortality, VAS, and SV-QLI/SCI after cervical fracture over 7 years follow-up.

Keywords: Ankylosing spondylitis; Cervical spine; Columna cervical; Diffuse idiopathic skeletal hyperostosis; Espondilitis anquilosante; Fractura; Fracture; Hiperostosis idiopática difusa; Lesión medular; Spinal cord injury.