Ossification of the Posterior Longitudinal Ligament in North American Patients: Does Presentation with Spinal Cord Injury Matter?

Sorafenib inhibits ossification of the posterior longitudinal ligament by blocking LOXL2-mediated vascularization

Ossification of the Posterior Longitudinal Ligament (OPLL) is a degenerative hyperostosis disease characterized by the transformation of the soft and elastic vertebral ligament into bone, resulting in limited spinal mobility and nerve compression. Employing both bulk and single-cell RNA sequencing, we elucidate the molecular characteristics, cellular components, and their evolution during the OPLL process at a single-cell resolution, and validate these findings in clinical samples. This study also uncovers the capability of ligament stem cells to exhibit endothelial cell-like phenotypes in vitro and in vivo. Notably, our study identifies LOXL2 as a key regulator in this process. Through gain-and loss-of-function studies, we elucidate the role of LOXL2 in the endothelial-like differentiation of ligament cells. It acts via the HIF1A pathway, promoting the secretion of downstream VEGFA and PDGF-BB. This function is not related to the enzymatic activity of LOXL2. Furthermore, we identify sorafenib, a broad-spectrum tyrosine kinase inhibitor, as an effective suppressor of LOXL2-mediated vascular morphogenesis. By disrupting the coupling between vascularization and osteogenesis, sorafenib demonstrates significant inhibition of OPLL progression in both BMP-induced and enpp1 deficiency-induced animal models while having no discernible effect on normal bone mass. These findings underscore the potential of sorafenib as a therapeutic intervention for OPLL.

Perioperative Complications of Laminoplasty in Degenerative Cervical Myelopathy -A Comparative Study Between Ossification of Posterior Longitudinal Ligament and Cervical Spondylotic Myelopathy Using a Nationwide Inpatient Database

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Laminoplasty (LAMP) is one of the effective methods to successfully achieve surgical decompression in patients with degenerative cervical myelopathy (DCM). However, little evidence exists regarding the perioperative complications in LAMP for patients with ossification of the longitudinal ligament (OPLL) compared with cervical spondylotic myelopathy (CSM). We aimed to investigate the perioperative complication rates and medical costs of DCM, including OPLL and CSM patients who underwent LAMP using a large national inpatient database.

METHODS

This study identified patients who underwent LAMP for OPLL and CSM from 2010 to 2016 using the Japanese Diagnosis Procedure Combination database. We compared the incidence of perioperative complications (systemic and local), reoperation rates, medical costs during hospitalization, and mortality were between the OPLL and CSM groups after propensity score matching.

RESULTS

This study included 22,714 patients (OPLL: 7485 patients, CSM: 15,229 patients). Consequently, 7169 pairs were matched. More perioperative systemic complications were detected in the OPLL group (one complication: 9.1% vs 7.7%; P = .002), especially for pneumonia (.5% vs .2%; P = .001) and dysphagia (.5% vs .2%; P = .004). The local complication rate was also higher in the OPLL group (paralysis: 1.1% vs .6%, P = .006; spinal fluid leakage: .4% vs .1%, P = .002). The hospitalization costs were approximately $2300 higher ($19,024 vs $16,770; P < .001) in the OPLL group.

CONCLUSIONS

More perioperative complications and higher medical costs were noted in patients with OPLL than in patients with CSM who underwent LAMP.