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  • Radiographic parameters affecting the degree of thoracic myelopathy in the patients with ossification of ligament flavum

    Final Number:

    Byung Jou Lee MD

    Study Design:

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2017 Annual Meeting - Late Breaking Science

    Introduction: Thoracic ossification of the ligamentum flavum (OLF) is a common cause of thoracic myelopathy. The measurement method for the thickness of the ligamentum flavum is not standardized, which causes confusion. We hypothesized that the area of OLF is a key morphologic parameter in the diagnosis of thoracic myelopathy due to OLF.

    Methods: A total of 203 patients who met the inclusion criteria were enrolled between January 1999 and December 2016. We measured the thickness of OLF (TOLF), cross sectional area of OLF (AOLF), anteroposterior canal diameter (APD), cross sectional area of the spinal canal (ASC), and the ratio of each of these parameters at the maximum thickness level. We divided the patients into two groups according to the presence or absence of thoracic myelopathy. We analyzed the relationship between the degree of ossification and myelopathy.

    Results: The best cut off point of ratio of AOLF was 33.00%, with 87.1% sensitivity, 87.3% specificity and AUC of 0.934 (95% CI, 0.899 – 0.969). The sensitivity and specificity of the ratio of AOLF were higher than those of other parameters. Postoperative clinical outcome was the best with 1.37 ± 0.82 of difference between post- JOA score and pre-JOA score, when patients with ratio of AOLF more than 40% and less than 45% underwent decompressive laminectomy for thoracic myelopathy due to OLF

    Conclusions: The ratio of AOLF was the most important parameter. Thus, to predict thoracic myelopathy due to OLF, the treating doctor should more carefully analyze the ratio of AOLF than other parameters. If the ratio of AOLF is > 33%, then the patient may be at a risk for myelopathy later in life, even if there is no myelopathy at present and surgical treatment is recommended before OLF take up half of the spinal canal.

    Patient Care: we can predict thoracic myelopathy due to OLF

    Learning Objectives: The aim of this study is to investigate radiographic parameters affecting the degree of thoracic myelopathy in the patients with OLF

    References: 1. Ahn DK, Lee S, Moon SH, Boo KH, Chang BK, Lee JI: Ossification of the ligamentum flavum. Asian Spine J 8:89-96, 2014 2. Aizawa T, Sato T, Sasaki H, Kusakabe T, Morozumi N, Kokubun S: Thoracic myelopathy caused by ossification of the ligamentum flavum: clinical features and surgical results in the Japanese population. J Neurosurg Spine 5:514-519, 2006 3. Baba H, Tomita K, Kawahara N, Kikuchi Y, Imura S: Spinal cord evoked potentials in thoracic myelopathy with multisegmental vertebral involvement. Spine (Phila Pa 1976) 17:1291-1295, 1992 4. Feng F, Sun C, Chen Z: A diagnostic study of thoracic myelopathy due to ossification of ligamentum flavum. Eur Spine J 24:947-954, 2015 5. He S, Hussain N, Li S, Hou T: Clinical and prognostic analysis of ossified ligamentum flavum in a Chinese population. J Neurosurg Spine 3:348-354, 2005 6. Inamasu J, Guiot BH: A review of factors predictive of surgical outcome for ossification of the ligamentum flavum of the thoracic spine. J Neurosurg Spine 5:133-139, 2006 7. Kang KC, Lee CS, Shin SK, Park SJ, Chung CH, Chung SS: Ossification of the ligamentum flavum of the thoracic spine in the Korean population. J Neurosurg Spine 14:513-519, 2011 8. Karavelioglu E, Kacar E, Gonul Y, Eroglu M, Boyaci MG, Eroglu S, et al: Ligamentum flavum thickening at lumbar spine is associated with facet joint degeneration: An MRI study. J Back Musculoskelet Rehabil 29:771-777, 2016 9. Kim YU, Park JY, Kim DH, Karm MH, Lee JY, Yoo JI, et al: The Role of the Ligamentum Flavum Area as a Morphological Parameter of Lumbar Central Spinal Stenosis. Pain Physician 20:E419-E424, 2017 10. Kolte VS, Khambatta S, Ambiye MV: Thickness of the ligamentum flavum: correlation with age and its asymmetry-an magnetic resonance imaging study. Asian Spine J 9:245-253, 2015 11. Koyanagi I, Imamura H, Fujimoto S, Hida K, Iwasaki Y, Houkin K: Spinal canal size in ossification of the posterior longitudinal ligament of the cervical spine. Surg Neurol 62:286-291; discussion 291, 2004 12. Kuh SU, Kim YS, Cho YE, Jin BH, Kim KS, Yoon YS, et al: Contributing factors affecting the prognosis surgical outcome for thoracic OLF. Eur Spine J 15:485-491, 2006 13. Lee RA, van Zundert AA, Breedveld P, Wondergem JH, Peek D, Wieringa PA: The anatomy of the thoracic spinal canal investigated with magnetic resonance imaging (MRI). Acta Anaesthesiol Belg 58:163-167, 2007 14. Liu N, Chen Z, Qi Q: Correlation between spinal canal encroachment and neurologic deficits in thoracic ossification of ligamentum flavum. CHINESE JOURNAL OF ORTHOPEDICS 27:481, 2007 15. Matsumoto Y, Harimaya K, Doi T, Kawaguchi K, Okada S, Inoguchi A, et al: Clinical characteristics and surgical outcome of the symptomatic ossification of ligamentum flavum at the thoracic level with combined lumbar spinal stenosis. Arch Orthop Trauma Surg 132:465-470, 2012 16. Matsunaga S, Sakou T: OPLL: disease entity, incidence, literature search, and prognosis. OPLL, 2nd edn. Springer, Tokyo:11-17, 2006 17. Min JH, Jang JS, Lee SH: Clinical results of ossification of the posterior longitudinal ligament (OPLL) of the thoracic spine treated by anterior decompression. J Spinal Disord Tech 21:116-119, 2008 18. Miyakoshi N, Shimada Y, Suzuki T, Hongo M, Kasukawa Y, Okada K, et al: Factors related to long-term outcome after decompressive surgery for ossification of the ligamentum flavum of the thoracic spine. J Neurosurg 99:251-256, 2003 19. Moon BJ, Kuh SU, Kim S, Kim KS, Cho YE, Chin DK: Prevalence, Distribution, and Significance of Incidental Thoracic Ossification of the Ligamentum Flavum in Korean Patients with Back or Leg Pain : MR-Based Cross Sectional Study. J Korean Neurosurg Soc 58:112-118, 2015 20. Munns JJ, Lee JY, Espinoza Orias AA, Takatori R, Andersson GB, An HS, et al: Ligamentum flavum hypertrophy in asymptomatic and chronic low back pain subjects. PLoS One 10:e0128321, 2015 21. Nishiura I, Isozumi T, Nishihara K, Handa H, Koyama T: Surgical approach to ossification of the thoracic yellow ligament. Surg Neurol 51:368-372, 1999 22. Okada K, Oka S, Tohge K, Ono K, Yonenobu K, Hosoya T: Thoracic myelopathy caused by ossification of the ligamentum flavum. Clinicopathologic study and surgical treatment. Spine (Phila Pa 1976) 16:280-287, 1991 23. Park BC, Min WK, Oh CW, Jeon IH, Kim SY, Kyung HS, et al: Surgical outcome of thoracic myelopathy secondary to ossification of ligamentum flavum. Joint Bone Spine 74:600-605, 2007 24. Park JY, Chin DK, Kim KS, Cho YE: Thoracic ligament ossification in patients with cervical ossification of the posterior longitudinal ligaments: tandem ossification in the cervical and thoracic spine. Spine (Phila Pa 1976) 33:E407-410, 2008 25. Prasad SS, O'Malley M, Caplan M, Shackleford IM, Pydisetty RK: MRI measurements of the cervical spine and their correlation to Pavlov's ratio. Spine (Phila Pa 1976) 28:1263-1268, 2003 26. Safak AA, Is M, Sevinc O, Barut C, Eryoruk N, Erdogmus B, et al: The thickness of the ligamentum flavum in relation to age and gender. Clin Anat 23:79-83, 2010 27. Sairyo K, Biyani A, Goel V, Leaman D, Booth R, Jr., Thomas J, et al: Pathomechanism of ligamentum flavum hypertrophy: a multidisciplinary investigation based on clinical, biomechanical, histologic, and biologic assessments. Spine (Phila Pa 1976) 30:2649-2656, 2005 28. Sanghvi AV, Chhabra HS, Mascarenhas AA, Mittal VK, Sangondimath GM: Thoracic myelopathy due to ossification of ligamentum flavum: a retrospective analysis of predictors of surgical outcome and factors affecting preoperative neurological status. Eur Spine J 20:205-215, 2011 29. Shiokawa K, Hanakita J, Suwa H, Saiki M, Oda M, Kajiwara M: Clinical analysis and prognostic study of ossified ligamentum flavum of the thoracic spine. J Neurosurg 94:221-226, 2001 30. Sun C, Chen Z: Clinical diagnosis of myelopathy resulted from thoracic ossification of the ligamentum flavum associated with cervical spondylosis. J Spine Surg 5:18-21, 2007 pain physician 2017;20:E419-E424: The role of the ligamentum flavum area as a morphological parameter of lumbar spinal stenosis

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