Nonrestrictive Fixation Strategy for Upper Cervical Spine Fractures Associated With Diffuse Idiopathic Skeletal Hyperostosis: A Case Report.

BACKGROUND: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by calcification and ossification of the anterior longitudinal ligament, forming multilevel bony bridges. This pathological change leads to spinal stiffness and produces a "long lever arm effect", making patients extremely prone to unstable upper cervical fractures even with low-energy injuries. Although traditional occipitocervical fusion or multilevel posterior fusion can provide stability, they can lead to a catastrophic loss of cervical mobility. We present a rare case of DISH in combination with Jefferson, hangman's, and C2 to C3 osteophyte fractures, along with a therapeutic strategy focused on functional preservation. CASE PRESENTATION: A 66-year-old man presented with cervical pain and limited mobility following a low-energy fall. Imaging confirmed the presence of a Gehweiler type III Jefferson fracture, a Levine-Edwards type IIa hangman fracture, and an associated C2 to C3 anterior osteophyte fracture, alongside characteristic features of DISH. A nonrestrictive fixation strategy was adopted to restore the stability of the fracture site while preserving part of the motor function of the upper cervical spine. C1-ring osteosynthesis was performed, and posterior long-segment internal fixation was applied to C2 to C4; the C1 construct was deliberately not linked to the subaxial construct. Postoperative assessments demonstrated adequate fracture healing, stable internal fixation, resolution of neck pain, and partial preservation of motor function in the upper cervical spine. CONCLUSIONS: For patients with DISH and complex upper cervical fractures, total segment fusion should not be pursued without careful consideration of functional outcomes. This case highlights a novel, deliberately uncoupled, segment-specific fixation strategy (coupling independent C1 ring fixation with a targeted subaxial construct). This approach fulfills local mechanical demands for fracture healing while maximizing the preservation of partial residual upper cervical motion.