Surgical outcomes of posterior thoracic interbody fusion for thoracic disc herniations

Surgical strategy for thoracic disc herniation (TDH) remains controversial. We have performed posterior thoracic interbody fusion (PTIF) by bilateral total facetectomies with pedicle screw fixation. The objectives of this retrospective study are to demonstrate the surgical outcomes of PTIF for TDH. We enrolled 11 patients who underwent PTIF for myelopathy due to TDH and were followed for at least 1 year. The mean age at surgery was 55.2 years and the average period of follow-up was 4.3 years. The levels of operation were T10-T11 in three cases, T12-L1 in three, and T2-T3, T3-T4, T9-T10, T11-T12, and T10-T12 in one case, respectively. The pre- and postoperative clinical status was evaluated according to the modified Frankel grade and the Japanese Orthopaedic Association (JOA) score modified for thoracic myelopathy. Additionally, postoperative complications were assessed. Local kyphosis at the operated segment and status of fusion were evaluated using plain radiographs and computed tomography. Improvement of at least one modified Frankel grade was observed in all but one patient. Average pre- and postoperative JOA scores were 4.9 and 8.8 points, respectively. The average recovery rate was 61 %. Bony union was observed in ten cases. One patient's postsurgical outcome resulted in pseudoarthrosis, which required revision surgery due to kyphosis deterioration. Cerebrospinal fluid leakage was observed in one patient postoperatively with neither neurological deficit nor evidence of infection. PTIF has produced satisfactory outcomes for myelopathy due to TDH. Therefore, PTIF is one of the surgical treatments of choice for patients with TDH causing myelopathy.