CT-based morphological analysis of spinal fractures in patients with diffuse idiopathic skeletal hyperostosis.

Purpose: To clarify correlations between spinal fracture and delayed paralysis in patients with diffuse idiopathic skeletal hyperostosis (DISH) using computed tomography (CT) with multiplanar reformatting (CT-MPR). DISH increases susceptibility to unstable spinal fractures, leading to neurological deterioration. The pathomechanism of the neurological injury is unclear.

Methods: This multicenter retrospective study included 42 DISH patients (32 male; 10 female) treated for 45 spinal fractures during a 5-year period. The mean age at the time of injury was 77.1 ± 10.1 years. The cause of injury, delay in diagnosis, fracture location, and neurological status were recorded, and anterior- and posterior-column fractures, a fracture displacement over 3 mm, and posterior-column ankylosis were assessed using CT-MPR.

Results: Most fractures (73.8%) resulted from trivial trauma, such as falling from a standing or sitting position. Diagnosis was delayed in 47.6% of the patients, primarily due to delays in seeking medical attention (65.0%). Although 78.6% of the patients were neurologically intact at the time of injury, 54.8% developed paralysis, defined by a change in one or more Frankel-score levels during short-term follow-up. Of the fractures, 39.1% were in the vertebral body, and 60.9% were at the disc level. Fractures with posterior-column ankylosis were significantly associated with delayed paralysis.

Conclusions: CT-MPR was useful for evaluating spinal fractures and determining treatment in patients with DISH. Fractures associated with posterior-column ankylosis resulted in unstable three-column injuries that led to delayed neurological deterioration. Early surgical stabilization of such fractures is recommended to avoid delayed paralysis.