Myxomatous degeneration of the ligamentum flavum of the lumbar spine

Abstract

Study design: Report of two cases of acute lumbar nerve root compression caused by myxomatous degeneration of the ligamentum¯avum. Objective: To report a rare cause of acute lumbar nerve root compression. Setting: Orthopaedic department, Osaka, Japan. Summary of background data: Two patients, both 50-year-old men presenting with signs and symptoms suggestive of acute lumbar nerve root compression were found to have a ligamentum¯avum mass. The masses were removed and the patients regained normal function postoperatively. Methods: To reveal the nature of the mass, histopathological studies were made. Continuous sections were prepared from the removed mass lesions. The sections were stained with hematoxylin and eosin, van Gieson's stain, azan stain, periodic acid Schi reaction, Alcian blue stain and von Kossa's stain. Results: Histological examination revealed myxomatous degeneration of the ligamentum avum. No elastic ®bers were found at the degeneration site. Di use mucopolysaccharide deposition was found at the degeneration site, however, no cyst was found. Collagen ®bers were not increased. Hypertrophy or ossi®cation of the ligamentum¯avum was not recognized in the sections. At a follow-up examination over 2 years later, the patients were free of symptoms and the ®ndings of a neurological examination were normal. Conclusion: Two cases of myxomatous degeneration of the ligamentum¯avum of the lumbar spine were reported, which have seldom been described as the cause of acute lumbar nerve root compression. Spinal Cord (2001) 39, 488 ± 491

Effect of ligamenta flava hypertrophy on lumbar disc herniation with contralateral symptoms and signs: a clinical and morphometric study

“…Fibrosis is the main cause of ligamentum flavum hypertrophy and is induced by mechanical stress which increases with the aging process [15]. There are a lot of reports about hypertrophied ligamentum flavum and its contribution to spinal stenosis and radiculopathy, but no reports about compression of roots resulting in radiculopathy of pure hypertrophied ligament without ossification, haematoma, pseudo-cystic or myxomatous degeneration of the ligamentum flavum [16–22]. …”

Cyst of the Ligamentum Flavum-Case Report-

“…Of course, the dynamics of the spine exert the greatest exercise loading on the joint, but some exercise loading is also exerted on the surrounding tissues such as the PLL and ligamentum flavum. 9,21,23,32,34) No reports have described the appearance of these cysts in any region other than the mobile spine. The T2-10 vertebrae mainly act with the ribs to form the thorax and are not generally considered to be part of the mobile spine.…”

“…3,4,6,8,28,30,34) Ligamentum flavum cyst is a type of juxtafacet cyst. 5,6,15,19,20) Cyst of the posterior longitudinal ligament (PLL) or the facet joint are also types of juxtafacet cyst.…”

Unusual Appearance of Lumbar Facet Synovial Cyst and Differential Diagnosis

“…In this manner, the discussion of the reported case must include ligamentum flavum calcification, ossification, hematoma, myxomatous or pseodocystic degeneration, and neoplasms such as schwannoma or neurofibroma with cystic degeneration and/or hemorrhage, as well as complicated juxtafacet joint cysts (ganglion, synovial cyst, ligamentum flavum cyst), instead of arachnoid cysts and perineural (Tarlov) cysts (2)(3)(4)(5). The mass had similar signal intensity on T1-weighted images and decreased signal intensity on T2weighted images in relation to the vertebral medullary body.…”