Benefits and Risks of Subsection Laminectomy with Pedicle Screw Fixation for Ossification of the Ligamentum Flavum of the Thoracic Spine: A Retrospective Study of 30 Patients

Background: This study aimed to evaluate the effectiveness of subsection laminectomy with pedicle screw fixation (SLPF) for the treatment of ossification of the ligamentum flavum of the thoracic spine. Material/Methods: Thirty patients (age, 40-71 years) with ossification of the ligamentum flavum of the thoracic spine underwent SLPF (13 men, 17 women). Operative time, intraoperative blood loss, preoperative and postoperative change in thoracic kyphosis, and perioperative complications were recorded. The Japanese Orthopedic Association (JOA) score for severity of myelopathy and the American Spinal Injury Association (ASIA) motor and sensory impairment scale were used before and after surgery. Results: Mean operative time for SLPF was 208.4 +/- 38.3 min and mean intraoperative blood loss was 689.3 +/- 171.7 ml. The mean JOA score significantly increased from 5.7 +/- 1.9 before surgery to 8.8 +/- 2.2 at one month after surgery and 9.3 +/- 2.7 at the last follow-up (P<0.01). Postoperative improvement in neurological function increased by 68.3 +/- 14.4%. The postoperative ASIA grades significantly improved compared with the preoperative grades (P<0.01). The mean local Cobb angle significantly decreased from 17.8 +/- 4.3 degrees before surgery to 15.4 +/- 3.6 degrees at one month after surgery and 15.8 +/- 3.8 degrees at the last follow-up (P<0.01). Three patients (10%) had operative cerebrospinal fluid (CSF) leak. Postoperatively, one patient had neurological deterioration, two patients had deep venous thrombosis (DVT), and one patient developed a wound infection. Conclusions: SLPF was an effective procedure for the treatment of ossification of the ligamentum flavum of the thoracic spine.