Circumferential Thoracic Cord Compression Due to Combined Ossified Yellow Ligament and Ossified Posterior...

Thoracic myelopathy caused by combined ossified yellow ligament (OYL) and ossified posterior longitudinal ligament (OPLL) is exceptionally rare and presents unique diagnostic and surgical challenges. We report a 45-year-old female with rapidly progressive gait disturbance and severe myelopathy found to have circumferential spinal cord compression at T3-T4 due to simultaneous dorsal OYL and ventral OPLL. MRI and CT imaging were essential in defining the extent of compression and ossification. Considering the morbidity of anterior thoracic exposure, a tailored posterior-only approach incorporating laminectomy, OYL excision, costotransversectomy-assisted partial OPLL decompression, and instrumented stabilization was performed, achieving adequate circumferential release. The patient demonstrated meaningful neurological recovery, improving from Nurick Grade 5 to Grade 3 within three months. This case highlights the importance of early recognition, comprehensive imaging, and individualized posterior-based strategies in managing complex upper thoracic stenosis caused by dual ossified pathologies.