Development of a treatment classification system and treatment strategy for ligamentous ossification disease-traditional and innovative surgical strategies

Abstract

Ligamentous ossification diseases like OPLL and OLF can cause severe neurological compromise. While whole-spine CT identifies ossified segments and MRI reveals cord compression/signal changes, treatment guidelines—especially for multi-level involvement—remain undefined, particularly with advancing anterior surgical techniques. In this retrospective study of 168 patients with ≥ 2-year follow-up, we classified cases into: Cervicothoracic (CT), Cervicolumbar (CL), Thoracolumbar (TL), and Cervicothoracolumbar (CTL) types. Diagnosis required CT-confirmed ossification plus cord compression/T2 signal change (cervical/thoracic) or OLF with Schizas grade ≥ C lumbar stenosis. Surgical prioritization emphasized clinical symptoms over signs, myelopathy over radiculopathy, and proximal over distal compression. Type-specific strategies included anterior/posterior decompression (ACAF/TACAF for CT-type), selective approaches (CL-type), and level-specific decompression (TL/CTL-types). All subtypes showed significant improvement in JOA (e.g., CT-subtype: 10.54 ± 2.19 to 15.15 ± 0.78), Nurick (e.g., 3.52 ± 1.24 to 1.48 ± 0.96), and ODI scores (e.g., 31.75 ± 8.50 to 16.50 ± 1.29). This strategy integrates clinical presentation with imaging criteria to guide level-specific surgical planning. Beyond radiological findings, symptomatology critically informs decision-making, enabling tailored decompression with validated functional outcomes across all ligamentous ossification subtypes.