Surgical Results of Patients with Myelopathy due to Ossification of the Ligamentum Flavum with Ossification of the Posterior Longitudinal Ligament or a Vertebral Fracture at the Same Level of the Thoracic Spine: A Retrospective Comparative Study

STUDY DESIGN: Retrospective and comparative study. PURPOSE: We assessed surgical treatment outcomes in patients with thoracic myelopathy due to ossification of the ligamentum flavum (OLF), and OLF combined with ossification of the posterior longitudinal ligament (OPLL) or vertebral fracture (VF) at the same level. OVERVIEW OF LITERATURE: OLF and OPLL cause severe thoracic myelopathy. Osteoporotic VF commonly occurs at the thoracolumbar junction. There have been no investigations of thoracic myelopathy due to OLF and VF. METHODS: Forty patients were divided among three groups: the OLF group (n=23): myelopathy due to OLF, the OLF+OPLL group (n=12): myelopathy due to OLF and OPLL, and the OLF+VF group (n=5): myelopathy due to OLF and VF. We recorded OLF, OPLL, and VF sites and operative procedures. Each patient’s neurological status, according to the Japanese Orthopaedic Association (JOA) score, and walking ability were evaluated pre- and postoperatively. RESULTS: Patients in the OLF+OPLL group were significantly younger than those in the other two groups. The preoperative JOA score was significantly lower in the OLF+VF than OLF group. The final JOA score was significantly lower in the OLF+VF than OLF and OLF+OPLL groups. The JOA score recovery rate was significantly lower in the OLF+VF than OLF group. Final walking ability was significantly worse in the OLF+OPLL and OLF+VF groups than in the OLF group and significantly worse in the OLF+VF than OLF+OPLL group. CONCLUSIONS: Thoracic myelopathy due to OLF+VF occurs primarily in older females, who also exhibit worse preoperative and postoperative neurological status, and worse walking ability, than patients with thoracic myelopathy due to OLF or OLF+OPLL.

Thoracic Myelopathy Caused by Ossified Ligamentum Flavum: Case Report

A rare case of thoracic myelopathy caused by the ossification of hypertrophied ligamentum flavum is presented. A fourty-year old male complained of decreased pain, temperature, touch sense at right lower limb, weak urinary stream, poor penile erection, and constipation. CT revealed an ovoid, homogeneously high density at the site of left T10-11 ligamentum flavum, which compressed the spinal cord posterolaterally. MR imaging showed significant spinal cord compression on the left posterolateral aspect at T10-11 level by a well-defined purely low-intensity signal lesion. Simple spine X-rays did not show any abnormality. T10 total laminectomy and removal of the ossified ligamentum flavum resolved his neurological dysfunction. Clinical summary of the case is presented and the corresponding literature are reviewed.