Factors for a Good Surgical Outcome in Posterior Decompression and Dekyphotic Corrective Fusion with Instrumentation for Thoracic Ossification of the Posterior Longitudinal Ligament: Prospective Single-Center Study.

BACKGROUND: Surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL) is still challenging, and factors for good surgical outcomes are unknown. OBJECTIVE: To identify factors for good surgical outcomes with prospective and comparative study. METHODS: Seventy-one consecutive patients who underwent posterior decompression and instrumented fusion were divided into good or poor outcome groups based on ≥50% and <50% recovery rates for the Japanese Orthopaedic Association score. Preoperative, intraoperative, and postoperative findings were compared in the 2 groups, and significant factors for a good outcome were analyzed. RESULTS: Patients with a good outcome (76%) had significantly lower nonambulatory rate and positive prone and supine position tests preoperatively; lower rates of T-OPLL, ossification of the ligamentum flavum, high-intensity area at the same level, thoracic spinal cord alignment difference, and spinal canal stenosis on preoperative magnetic resonance imaging; lower estimated blood loss; higher rates of intraoperative spinal cord floating and absence of deterioration of intraoperative neurophysiological monitoring; and lower rates of postoperative complications (P < .0005). In multivariate logistic regression analysis, negative prone and supine position test (odds ratio [OR]: 17.00), preoperative ambulatory status (OR: 6.05), absence of T-OPLL, ossification of the ligamentum flavum, high-intensity area at the same level (OR: 5.84), intraoperative spinal cord floating (OR: 4.98), and lower estimated blood loss (OR: 1.01) were significant factors for a good surgical outcome. CONCLUSION: This study demonstrated that early surgery is recommended during these positive factors. Appropriate surgical planning based on preoperative thoracic spinal cord alignment difference, as well as sufficient spinal cord decompression and reduction of complications using intraoperative ultrasonography and intraoperative neurophysiological monitoring, may improve surgical outcomes.