Liu Xiao, Zhu Bin, Liu Xiaoguang, Liu Zhongjun, and Dang Gengting

Background: The treatment strategies for multilevel T-OPLL (three or more segments) were rarely reported.This study is to investigate the clinical outcomes and complications of circumferential decompression for multilevel ossification of the posterior longitudinal ligament (OPLL) of the thoracic spine and compare two different methods in the management of the OPLL.

Methods: Data of sequentially-treated patients who received surgical treatment for thoracic spinal stenosis caused by multilevel OPLL from January 2005 to February 2012 were retrospectively reviewed. Based on the surgical approaches applied, the patients were divided into 2 groups: group A :patients who received posterior decompression, and group B :patients who received circumferential decompression via the posterior approach. Group B were furtherdivided into two subgroups; in subgroup 1(resection group), the OPLL was completely resected,while in subgroup 2, the OPLL was floated(floating group).

Results: A total of 49 patients were included in the study. Fourteen patients with single posterior decompression were included in Group A, 35 patients who received circumferential decompression and were included into Group B, In Group B, 29 patientshad complete resection of the ossified PLL whilethe other six received a flotation procedure.The follow-up data was available in 39 patients. Mean JOA scores improved from 5.4±1.8 to 7.5±2.8 in Group A and from 3.7±1.8 to 7.9±2.4 in Group B. Main complications included cerebrospinal fluid (CSF) leakage and postoperative neurologic deterioration (ND). 23 of 25 cases with postoperative CSF leakage achieved a complete recovery at last follow-up and 12 of the 15 cases with ND achieved some neurological improvement at last follow-up.

Conclusions: Circumferential decompression via the posterior approach is an effective surgical method for thoracic spinal stenosis caused by multilevel OPLL of the thoracic spine. Patients who have received complete resection of the ossified PLL may have better recovery rate than the “floating” group.