Ossification of the ligamentum flavum (OLF) is a phenomenon where there is a formation of ossific-calcific components in the ligamentum flavum. It is recognised causes of myelopathy (especially in the thoracic and to a lesser degree the cervical region).
The condition as a whole is uncommon. There is a higher prevalence in East Asian ethnic groups (especially Japan).
Both intrinsic (genetic and dietary factors) and extrinsic causes (biomechanical alterations) have been postulated. The spinal cord tends to usually get compressed from the posterior side and patients, therefore, tend to show symptoms such as loss of balanced walking (similar to posterior cord syndrome).
In the cervical region, it can uncommonly be associated with ossification of the posterior longitudinal ligament 9.
Treatment and prognosis
Management options vary from being conservative to surgical decompression. Some authors propose a laminectomy combined with lateral fusion at the treatment of choice 8. The postoperative outcome is generally considered good 8.
History and etymology
It is thought to have been first reported by Polgar on a lateral radiograph 1.
- 1. Ahn DK, Lee S, Moon SH et-al. Ossification of the ligamentum flavum. Asian Spine J. 2014;8 (1): 89-96. doi:10.4184/asj.2014.8.1.89 - Free text at pubmed - Pubmed citation
- 2. Fong SY, Wong HK. Thoracic myelopathy secondary to ligamentum flavum ossification. Ann. Acad. Med. Singap. 2004;33 (3): 340-6. Pubmed citation
- 3. Kang KC, Lee CS, Shin SK et-al. Ossification of the ligamentum flavum of the thoracic spine in the Korean population. J Neurosurg Spine. 2011;14 (4): 513-9. doi:10.3171/2010.11.SPINE10405 - Pubmed citation
- 4. Sanghvi AV, Chhabra HS, Mascarenhas AA et-al. 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. 2011;20 (2): 205-15. doi:10.1007/s00586-010-1423-9 - Free text at pubmed - Pubmed citation4.
- 5. Miyakoshi N, Shimada Y, Suzuki T et-al. Factors related to long-term outcome after decompressive surgery for ossification of the ligamentum flavum of the thoracic spine. J. Neurosurg. 2003;99 (3 Suppl): 251-6. Pubmed citation
- 6. Kotani Y, Takahata M, Abumi K et-al. Cervical myelopathy resulting from combined ossification of the ligamentum flavum and posterior longitudinal ligament: report of two cases and literature review. Spine J. 2013;13 (1): e1-6. doi:10.1016/j.spinee.2012.10.038 - Pubmed citation
- 7. Wang W, Kong L. Ossification of ligamentum. J Neurosurg Spine. 2007;6 (1): 96. doi:10.3171/spi.2007.6.1.20 - Pubmed citation
- 8. Kang KC, Lee CS, Shin SK et-al. Ossification of the ligamentum flavum of the thoracic spine in the Korean population. J Neurosurg Spine. 2011;14 (4): 513-9. doi:10.3171/2010.11.SPINE10405 - Pubmed citation
- 9. Guo Q, Ni B, Yang J et-al. Simultaneous ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum causing upper thoracic myelopathy in DISH: case report and literature review. Eur Spine J. 2011;20 Suppl 2 (S2): S195-201. doi:10.1007/s00586-010-1538-z - Pubmed citation