Clinical results of ossification of the posterior longitudinal ligament (OPLL) of the thoracic spine treated by anterior decompression

Study Design: A retrospective study. Objective: To evaluate surgical outcomes and prognostic factors of thoracic ossification of the posterior longitudinal ligament (OPLL) treated by anterior decompression. Summary of Background Data: The results of surgery for thoracic myelopathy caused by OPLL have been recognized as unfavorable. Anterior decompression is the logical treatment option for thoracic OPLL, but it is technically demanding and is associated with a high rate of complications. Methods: Nineteen patients who underwent anterior decompression were included in this study. Modified Japanese Orthopedic Association (JOA) scores and recovery rates were used to evaluate the outcomes. The relationship between the recovery rate and the following factors was investigated statistically: age, sex, duration of symptoms, preoperative JOA score, the degree of stenosis, the extent of decompression, the type of OPLL, the presence of signs of dural penetration, the presence of cerebrospinal fluid leakage, the presence of high signal intensity in the cord, and the presence of coexisting pathologies requiring surgical intervention. Results: The final outcome was excellent in 4 (21.1%) patients good in 2 (10.5%), fair in 7 (36.8%), unchanged in 4 (21.1%), and worsened in 2 (10.5%). The only statistically significant factor affecting outcomes was the preoperative JOA score. The complications included 2 (10.5%) patients with neurologic deterioration and 6 (31.6%) patients with cerebrospinal fluid leakage. Conclusions: We evaluated the outcomes and factors affecting the surgical outcomes of 19 patients with thoracic OPLL treated with anterior decompression. In this small series, we found that some patients undergoing anterior decompression for thoracic OPLL clinically improved, however, a significant percentage did not. Anterior decompression is technically demanding and is associated with a high rate of complications. When poor preoperative JOA scores and immediate postoperative neurologic deterioration are present, poor outcomes may be expected.