1. 2020;23;E475-E486Translaminar Osseous Channel–Assisted Full-Endoscopic Flavectomy Decompression of Thoracic Myelopathy Caused by Ossification of the Ligamentum Flavum: Surgical Technique and Results
   Retrospective Study
   Jun Ao, MD, Ansu Wang, MS, Jianpu Qin, MS, Jialin He, MS, Lei Liu, MS, Menghan Cai, MS, Qian Du, MD, Wei-Jun Kong, MD, Zhijun Xin, MD, and Wen-Bo Liao, MD.

BACKGROUND: Previous surgical procedures for the treatment of thoracic myelopathy (TM) due to ossification of the ligamentum flavum (OLF) were accompanied  by significant trauma and risk.

OBJECTIVES: Report a novel minimally invasive technique, translaminar osseous channel–assisted posterior percutaneous full-endoscopic flavectomy (p-PEF), as an alternative surgical strategy for the treatment of OLF-related TM.

STUDY DESIGN: A retrospective cohort study.

SETTING: A center for spine surgery and pain medicine.

METHODS: Thirteen patients with TM caused by isolated OLF who underwent translaminar osseous channel–assisted p-PEF were retrospectively analyzed. Preoperative and postoperative radiographic findings and clinical results were compared to confirm the efficacy of the procedure and perioperative complications were investigated to evaluate the technical safety.

RESULTS: All 13 patients with 23 isolated ossified sites were successfully treated with the translaminar osseous channel–assisted p-PEF technique and no additional internal fixation was needed. With an average follow-up of 29.2 months (range, 24–36 months), no local instability was detected. The preoperative and final follow-up cross-sectional area of the stenotic dural sac was 47.87 ± 8.98 mm2 and 130.47± 19.07 mm2, respectively (P < 0.0001). The mean modified Japanese Orthopaedic Association score was significantly improved from 3.54 ± 1.26 points preoperatively to 9.07 ± 1.48 points at final follow-up (P < 0.0001). The Visual Analog Scale scores of thoracolumbar backaches were 5.3 ± 1.2 before surgery and 0.69 ± 0.75 at final follow-up (P = 0.001). No serious complications ensued.

LIMITATIONS: This was a retrospective study with several limitations, including the lack of a control group, small number of included samples and unavoidable nature of the single-center study design.

CONCLUSIONS: Translaminar osseous channel–assisted p-PEF technique, with less tissue trauma and impact on the stability of the spine, can provide adequate decompression and satisfying outcomes in the treatment of OLF-related TM and should be considered as an alternative procedure for isolated OLF.

KEY WORDS: Translaminar osseous channel, percutaneous full-endoscopic flavectomy, thoracic myelopathy, ossification of ligamentum flavum, minimally invasive spine surgery