Genetic Odyssey to Ossification of the Posterior Longitudinal Ligament in the Cervical Spine: A Systematic Review

Abstract

Despite numerous studies, the pathogenesis of ossification of the posterior longitudinal ligament (OPLL) is still unclear. Previous genetic studies proposed variations in genes related to bone and collagen as a cause of OPLL. It is unclear whether the upregulations of those genes are the cause of OPLL or an intermediate result of endochondral ossification process. Causal variations may be in the inflammation-related genes supported by clinical and updated genomic studies. OPLL demonstrates features of genetic diseases but can also be induced by mechanical stress by itself. OPLL may be a combination of various diseases that share ossification as a common pathway and can be divided into genetic and idiopathic. The phenotype of OPLL can be divided into continuous (including mixed) and segmental (including localized) based on the histopathology, prognosis, and appearance. Continuous OPLL shows substantial overexpression of osteoblast-specific genes, frequent upper cervical involvement, common progression, and need for surgery, whereas segmental OPLL shows moderate-to-high expression of these genes and is often clinically silent. Genetic OPLL seems to share clinical features with the continuous type, while idiopathic OPLL shares features with the segmental type. Further genomic studies are needed to elucidate the relationship between genetic OPLL and phenotype of OPLL.

Factors Associated With Repeat Surgery in Cervical Ossification of the Posterior Longitudinal Ligaments

“…Extensive research, including studies on OPLL types and genetics, is being conducted to conquer this disease. 29 If the likelihood of OPLL growth and subsequent reoperation could be accurately predicted by assessing the shape of OPLL before surgery, it would be possible to choose the initial surgery appropriately to reduce the probability of reoperation. It is hoped that ongoing advancements in artificial intelligence techniques will contribute to such research.…”

“…Cervical OPLL significantly impacts the quality of life over a patient’s lifetime. Extensive research, including studies on OPLL types and genetics, is being conducted to conquer this disease 29 . If the likelihood of OPLL growth and subsequent reoperation could be accurately predicted by assessing the shape of OPLL before surgery, it would be possible to choose the initial surgery appropriately to reduce the probability of reoperation.…”

Concentration-Dependent Efficacy of Recombinant Human Bone Morphogenetic Protein-2 Using a HA/β-TCP Hydrogel Carrier in a Mini-Pig Vertebral Oblique Lateral Interbody Fusion Model

“…Bone morphogenetic proteins (BMPs) are multifunctional growth factors belonging to the transforming growth factor-β superfamily that were discovered during the demineralization process of cortical bone, and are potent factors that induce bone and cartilage formation and bone regeneration [1][2][3][4][5]. BMP is currently used in various applications, such as the treatment of degenerative spinal disease and vertebral fractures, spine fusion, dental surgery, and facial surgery.…”

“…Spine surgeons have used BMP-2 for anterior cervical fusion as an off-label application, and the surgery showed a good fusion rate and a good prognosis. However, serious side effects, such as airway narrowing and death due to soft tissue inflammation and swelling, have also been reported [4,5,7,8].…”

Comparison of the outcome after anterior cervical ossified posterior longitudinal ligament en bloc resection versus posterior total laminectomy and fusion in patients with ossification of the cervical posterior longitudinal ligament: a prospective randomized controlled trial

“…Ossification of the posterior longitudinal ligament (OPLL) is a common cause of radiculopathy and myelopathy. 1 It often requires surgery to achieve decompression of the neural elements. 2 Anterior and posterior surgical approaches are currently the mainstays of treatment, both having advantages and disadvantages.…”