Anterior corpectomy and fusion for severe ossification of posterior longitudinal ligament in the cervical spine

Approach-related complications after decompression for cervical ossification of the posterior longitudinal ligament

The surgical management of compressive cervical ossification of the posterior longitudinal ligament (OPLL) can be challenging. Traditionally, approach indications for decompression of cervical spondylotic myelopathy have been used. However, the postoperative complication profile after cervical OPLL decompression is unique and may require an alternative approach paradigm. The authors review the literature on approach-related OPLL complications and suggest a management strategy for patients with single- or multiple-segment OPLL with or without greater than 50% canal stenosis.

Ossification of the posterior longitudinal ligament: a review

Ossification of the posterior longitudinal ligament (OPLL) is most commonly found in men, the elderly, and Asian patients. There are many diseases associated with OPLL, such as diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, and other spondyloarthropathies. Several factors have been reported to be associated with OPLL formation and progression, including genetic, hormonal, environmental, and lifestyle factors. However, the pathogenesis of OPLL is still unclear. Most symptomatic patients with OPLL present with neurological deficits such as myelopathy, radiculopathy, and/or bowel and bladder symptoms. There are some reports of asymptomatic OPLL. Both static and dynamic factors are related to the development of myelopathy. Plain radiography, CT, and MR imaging are used to evaluate OPLL extension and the area of spinal cord compression. Management of OPLL continues to be controversial. Each surgical technique has some advantages and disadvantages, and the choice of operation should be made case by case, depending on the patient's condition, level of pathology, type of OPLL, and the surgeon's experience. In this paper, the authors attempt to review the incidence, pathology, pathogenesis, natural history, clinical presentation, classification, radiological evaluation, and management of OPLL.

Cervical spinal canal stenosis: the differences between stenosis at the lower cervical and multiple segment levels

The lower cervical segments are commonly the level responsible for cervical spondylotic myelopathy; however, we rarely encounter stenosis at the upper cervical segment in a clinical setting. We assumed that there might be some differences between the pathogenetic mechanisms underlying the development of cervical canal stenosis at different segments. We performed positional MRI in the weight-bearing position for 295 consecutive symptomatic patients. All subjects were classified into four groups (A: normal; B: C3-4 stenosis; C: C5-6 stenosis; D: two-level cervical segments stenosis, stenosis at C3-4 and C5-6). Age, sagittal cervical canal diameter, cervical intervertebral disc degeneration, cervical cord compression, and cervical mobilities were evaluated for each group. Group B showed a narrow cervical spinal canal structure at the C3 to C4 pedicle levels, while groups C and D showed narrow structures at the C4 to C6 pedicle levels in the cervical spine. Additionally, the sagittal cervical canal diameters at all pedicle levels, except C7, in group D were significantly smaller than those observed in group C. We demonstrated the differences in the pathogenetic processes for the development of cervical spinal canal stenosis between C3-4, C5-6, and two-level cervical segments stenosis. Our results suggest that the developmental morphological structure of the cervical spinal canal plays an important role in the development of cervical canal stenosis at different segments. Moreover, individuals with sagittal cervical canal diameters of less than 13 mm may be exposed to an increased risk for future development of cervical spinal canal stenosis at the upper cervical segments following stenosis at the lower cervical segments.

Is ossification of posterior longitudinal ligament an enthesopathy?

The purpose of this study was to investigate the relationship of ossification of posterior longitudinal ligament (OPLL) with enthesis, the site where the posterior longitudinal ligament (PLL) attaches to the vertebral body, by multi-detector CT reconstruction images. Twenty-nine patients with OPLL were studied. According to the plaques' continuity to the vertebral body, OPLL plaques were classified into two categories: "free" and "contiguous". A "broken sign" was defined as a crack between two plaques. The sites where each "contiguous" plaque attached to the vertebral body were then analysed. There were 78 ossified plaques in total, and six were "free". There were eight cases with a "broken sign", including six "free" ones. The site where all 72 "contiguous" plaques attached to the vertebral body included the zone where the PLL enthesis was situated, while other zones were included in only part of the plaques. Our conclusion was that there might be no real "free type" ossified plaques, and OPLL could start from enthesis, which indicated OPLL could be a kind of enthesopathy.

Full-endoscopic anterior decompression versus conventional anterior decompression and fusion in cervical disc herniations

Anterior cervical decompression and fusion (ACDF) is the standard for cervical discectomies. With the full-endoscopic anterior cervical discectomy (FACD) a minimally invasive procedure is available. The objective of this prospective, randomised, controlled study was to compare the results of FACD with those of ACDF in mediolateral soft disc herniations. A total of 103 patients with ACDF or FACD were followed up for two years. In addition to general parameters specific measuring instruments were used. Postoperatively 85.9% of the patients no longer had arm pain, and 10.1% had occasional pain. There were no significant clinical differences between the decompression with or without fusion. The full-endoscopic technique afforded advantages in operation technique, rehabilitation and soft tissue injury. The recorded results show that FACD is a sufficient and safe alternative to conventional procedures when the indication criteria are fulfilled. At the same time, it offers the advantages of a minimally invasive intervention.