Case of diffuse idiopathic skeletal hyperostosis and cervical ossification of the anterior longitudinal ligament causing progressive dysphagia plus ossification of the posterior longitudinal ligament contributing to compressive myelopathy

Background: Cervical diffuse idiopathic skeletal hyperostosis (DISH) combined with ossification of the anterior longitudinal ligament (OALL) and ossification of the posterior longitudinal ligament (OPLL) can collectively and respectively cause dysphagia and cervical myelopathy. Case Description: A 69-year-old male presented with progressive dysphagia and quadriparesis (modified Japanese Orthopedic Association [mJOA] score: 11). Radiographic imaging confirmed DISH with continuous flowing ossification from C3 to C6 and marked OALL causing esophageal compression, alongside multilevel OPLL causing severe cervical spinal cord compression. The patient underwent single-stage, sequential circumferential decompression and fusion (anterior C3–C6 discectomy and fusion combined with posterior C3–C6 laminectomy and lateral mass screw fixation). Postoperatively, dysphagia completely resolved, and neurological function improved, with the mJOA score increasing from 11 to 14. Conclusion: Coexisting DISH/OALL and OPLL can simultaneously induce severe dysphagia and cervical myelopathy. In such complex cases, circumferential decompression and fusion may improve or resolve both the dysphagia and myelopathy.