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Year : 2016  |  Volume : 64  |  Issue : 4  |  Page : 837--838

Is instability the nodal point of pathogenesis for both cervical spondylotic myelopathy and ossified posterior longitudinal ligament?

Atul Goel 
 Department of Neurosurgery, Seth G.S. Medical College and K.E.M. Hospital, Mumbai, Maharashtra, India

Correspondence Address:
Atul Goel
Department of Neurosurgery, Seth G.S. Medical College and K.E.M. Hospital, Mumbai, Maharashtra

How to cite this article:
Goel A. Is instability the nodal point of pathogenesis for both cervical spondylotic myelopathy and ossified posterior longitudinal ligament?.Neurol India 2016;64:837-838

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Goel A. Is instability the nodal point of pathogenesis for both cervical spondylotic myelopathy and ossified posterior longitudinal ligament?. Neurol India [serial online] 2016 [cited 2022 Jul 5 ];64:837-838
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With interest, I read the recent article by Gupta and Rajshekhar [1] and the Editorial Debate by Muzumdar, Muthukumar, and Sengupta [2],[3],[4] regarding the treatment of ossified posterior longitudinal ligament (OPLL) and multilevel cervical spondylotic degenerative myelopathy. Gupta and Rajshekhar present their experience with three-level corpectomy and subsequent fixation-stabilization using iliac crest graft for both these clinical entities. We wish to present our recently published thoughts on the subjects.

The studies regarding pathogenesis of multilevel cervical spondylotic degeneration has been disc-centric for over a century. This is more because the disc and its height alterations were more easily observed on plain radiographs that formed the bottom-line of investigations for several decades. The classic description of the beginning of pathogenesis of spondylosis has been related to reduction in the disc space height due to age-related decrease in its “water” content. The pathological association of spondylotic degeneration such as disc bulge into the spinal canal, osteophyte formation, and ligamental thickening is attributed to additional or associated alterations. The overall consequence of the entire spectrum of alterations is reduction in the spinal and root canal dimensions. Improved computer-based investigations such as computerized tomography scanning and magnetic resonance imaging showed the cord compression and its effects on the cord parenchyma rather clearly. In general, the disease process is considered to be a stable anomaly and the treatment is focused on “decompression” of the compressing elements of disc, osteophytes, and ligaments. The aim of surgery is to widen the spinal and root canal dimensions aiming to make the root and cord “breathe” easily and fully. The issue of instability arises when the decompressive surgery either from the anterior approach by single or multilevel discectomy and/or corpectomy; or from the posterior approach by laminectomy or laminoplasty is expected to have destabilizing effects either in the immediate postoperative phase or as a delayed consequence.

We recently proposed an alternative hypothesis regarding the pathogenesis of degenerative spondylosis that can have revolutionary effects on the treatment.[5],[6],[7] We proposed that the primary nodal point of pathogenesis of spondylotic disease is instability of the spine that is manifested at the facets. The instability is of “vertical” type wherein the superior facets slip over the inferior facets resulting in their listhesis or telescoping.[5] Although retrolisthesis of facets has been identified in spinal degeneration, it has been considered to be the effect of disc space reduction and degeneration rather than a primary phenomenon. Instability of the spine is related to lifelong standing human posture, muscle weakness that is secondary to muscle abuse, disuse, or injury resulting in slipping or listhesis of facets. Due to the oblique profile of cervical and dorsal spinal facets and the vertical profile of lumbar facets, identification of listhesis or instability at this level is difficult or impossible even with modern imaging techniques. We speculated that listhesis of facets results in reduction in the vertical height and buckling of the ligamentum flavum and posterior longitudinal ligament; osteophyte formation and disc space reduction and herniation are all secondary and probably protective responses to instability.[5],[6],[7] Based on this hypothesis, we earlier proposed facet distraction using “Goel facet spacer” and aimed at distraction arthrodesis of the facets.[8],[9],[10],[11] We reported that our technique resulted in reduction in the bulging of ligamentum flavum and posterior longitudinal ligament and restoration in the disc space height. We identified that with the proposed technique, there is a potential for reduction in the size of the osteophytes that may not necessarily be resected.[6] The procedure resulted in reduction of listhesis and directly increased the spinal and root canal dimensions without removal of any part of the disc, ligaments, bones, or osteophytes.[5],[6],[7] We reported remarkable clinical improvement following the treatment. As we mature in our understanding of spinal degeneration, we identify that more than neural deformation or compression, it is repeated microinjuries to the neural structures due to instability that is the cause of symptoms.[7] We proposed that “only stabilization” of the affected spinal segments may be the optimum mode of surgical treatment.[12],[13],[14],[15] Consequently, we resorted to transarticular method of spinal segmental fixation and identified that this surgical treatment forms the most stable and most firm form of spinal fixation.[14] Over the years, we have identified satisfactory clinical outcome following such treatment. The treatment thus changed from decompression of the neural structures to fixation and stabilization.

Multilevel OPLL has traditionally been considered to be a “stable” disease process. Ossification of ligaments has been speculated to add to the stability. We recently identified that pathogenesis of OPLL may also be related to instability and resorted to “only-fixation” by the transarticular technique and demonstrated satisfactory outcomes in this otherwise formidable surgical problem.[16],[17],[18] No form of decompression that involved removal of any part of bone or soft tissue was performed and the ossified part of the ligaments was not even handled during the surgery. Although the OPLL presents a grotesque radiological image and cord compression, instability and microtrauma related to instability appear to be the prime cause of symptoms. It appears that understanding the fact that instability is the primary issue in the pathogenesis of disease and maturation of symptoms in OPLL, can lead to a rational, quick, and relatively safe surgical conduct.

Although the results of multilevel corpectomy and subsequent iliac crest stabilization as shown by Gupta and Rajshekhar have been satisfactory, the positive results seem to be related to the long-term experience of the senior author.[1] Even then, there have been serious complications of dysphagia and cerebrospinal fluid fistulae.

Over the years, with our evolving experience, we are convinced that treatment that involves transarticular fixation and aiming at arthrodesis without any form of decompression can be a relatively simple and quick form of treatment that is rational and philosophical for both single and multilevel cervical spondylotic degeneration and OPLL. Identification of the presence of facetal instability during surgery by direct observation of the status of facets and manual handling of bones forms an important parameter. Our long-term experience in the handling of facets of the craniovertebral junction and of the subaxial spine assisted in decision-making.[19],[20]

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Conflicts of interest

There are no conflicts of interest.


1Gupta A, Rajshekhar V. Functional and radiological outcome in patients undergoing three-level corpectomy for multilevel cervical spondylotic myelopathy and ossified posterior longitudinal ligament. Neurol India 2016;64:90-6.
2Muzumdar D. Surgery for multilevel cervical spondylotic myelopathy and ossified posterior longitudinal ligament. Neurol India 2016;64:16-8.
3Muthukumar N. Multilevel cervical myelopathy due to cervical spondylosis/ossification of posterior longitudinal ligament – A complex problem. Neurol India 2016;64:19-22.
4Sengupta DK. Functional and radiological outcome in patients undergoing a three-level corpectomy for multilevel cervical spondylotic myelopathy and ossified posterior longitudinal ligament. Neurol India 2016;64:23-4.
5Goel A. Vertical facetal instability: Is it the point of genesis of spinal spondylotic disease? J Craniovertebr Junction Spine 2015;6:47-8.
6Goel A. Is it necessary to resect osteophytes in degenerative spondylotic myelopathy? J Craniovertebr Junction Spine 2013;4:1-2.
7Goel A. Not neural deformation or compression but instability is the cause of symptoms in degenerative spinal disease. J Craniovertebr Junction Spine 2014;5:141-2.
8Goel A. Facet distraction-arthrodesis technique: Can it revolutionize spinal stabilization methods? J Craniovertebr Junction Spine 2011;2:1-2.
9Goel A. Facet distraction spacers for treatment of degenerative disease of the spine: Rationale and an alternative hypothesis of spinal degeneration. J Craniovertebr Junction Spine 2010;1:65-6.
10Goel A, Shah A. Facetal distraction as treatment for single- and multilevel cervical spondylotic radiculopathy and myelopathy: A preliminary report. J Neurosurg Spine 2011;14:689-96.
11Goel A, Shah A, Jadhav M, Nama S. Distraction of facets with intraarticular spacers as treatment for lumbar canal stenosis: Report on a preliminary experience with 21 cases. J Neurosurg Spine 2013;19:672-7.
12Goel A. 'Only fixation' as rationale treatment for spinal canal stenosis. J Craniovertebr Junction Spine 2011;2:55-6.
13Goel A. Only fixation for cervical spondylosis: Report of early results with a preliminary experience with 6 cases. J Craniovertebr Junction Spine 2013;4:64-8.
14Goel A. Alternative technique of cervical spinal stabilization employing lateral mass plate and screw and intra-articular spacer fixation. J Craniovertebr Junction Spine 2013;4:56-8.
15Goel A. Can decompressive laminectomy for degenerative spondylotic lumbar and cervical canal stenosis become historical? J Craniovertebr Junction Spine 2015;6:144-6.
16Goel A, Nadkarni T, Shah A, Rai S, Rangarajan V, Kulkarni A. Is only stabilization an ideal treatment of OPLL? Report of early results with a preliminary experience with 14 cases. World Neurosurg 2015;84:813-9.
17Goel A. Ossified posterior longitudinal ligament (OPLL): Evaluation of 'only fixation' as rationale treatment option. Int J Neurol Neurosurg 2015;7:45-7.
18Goel A. Spinal fixation as treatment of ossified posterior longitudinal ligament. J Craniovertebr Junction Spine 2015;6:99-101.
19Goel A, Desai KI, Muzumdar DP. Atlantoaxial fixation using plate and screw method: A report of 160 treated patients. Neurosurgery 2002;51:1351-6.
20Goel A, Laheri VK. Plate and screw fixation for atlanto-axial dislocation (Technical report). Acta Neurochir (Wien) 1994;129:47-53.