Outcomes of Surgical Treatment for Thoracic Myelopathy A Single-institutional Study of 73 Patients

Study Design. Retrospective study. Objective. The aim was to investigate the clinical outcomes in patients with thoracic myelopathy in a single institution and to identify prognostic factors for poor outcomes. Summary of Background Data. Because of the rarity of thoracic myelopathy, a few studies have analyzed a large number of clinical results for patients with thoracic myelopathy treated in a single institution. Methods. Seventy-one patients who underwent surgical treatment for thoracic myelopathy between 2000 and 2011 in a single institution were included in this analysis. We investigated the patients' characteristics, surgical outcomes, and prognostic factors for poor outcomes. Results. Of the 73 patients, eight patients had disc herniation (DH) or spinal stenosis (SS), 10 patients had ossification of the posterior longitudinal ligament (OPLL), 40 patients had ossification of the ligamentum flavum (OLF), and 15 patients had OPLL + OLF. The mean patient age at the time of surgery was 61.9 years. Thoracic myelopathy was caused by OPLL and/or OLF in 65 patients (89%). Fifty-eight patients underwent laminectomy, eight patients underwent laminectomy and posterior fusion, four patients underwent OPLL extirpation and posterior fusion, and three patients underwent OPLL extirpation. The mean Japanese Orthopedic Association Scoring System scores before surgery and at the final follow-up examination were 6.0 +/- 1.8 and 7.7 +/- 2.0 points, respectively, yielding a mean recovery rate of 30% +/- 43%. The JOA score improved significantly postoperatively (P < 0.05). Risk factors for poor outcomes were longer preoperative symptom duration, preoperative JOA score<7, and OPLL and/or OLF. Large blood loss volume was significantly associated with a worse postoperative JOA score. Conclusion. A considerable degree of neurological recovery was observed after surgical treatment in patients with thoracic myelopathy. Prognostic factors for poor outcomes were longer preoperative duration of symptoms, worse preoperative symptoms, OPLL and/or OLF, and large volume of intraoperative bleeding.