title: Calcium pyrophosphate crystal deposition in the ligamentum flavum of degenerated lumbar spine: histopathological and immunohistological findings.
abstract: We investigated the histological and immunohistochemical features of degenerative changes in the ligamentum flavum of the lumbar spine with calcium crystal deposition. We investigated degenerative changes in 270 ligamentum flavum specimens harvested from 198 patients who underwent decompressive surgeries for lumbar spinal canal stenosis. En bloc sections of the ligamentum flavum were examined histologically. We also examined immunoreactivity for transforming growth factor (TGF)-beta, vascular endothelial growth factor (VEGF), CD34, and CD68; immunoblot analysis for VEGF; and terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end-labeling (TUNEL) method. The ligamentum flavum showed fragmented and disorganized elastic fiber bundles with increased collagen fibrils in the matrix. Calcium deposition, which was identified as calcium pyrophosphate dihydrate crystals, was evident in 72 of 198 patients and in 99 of 270 samples, and was associated with appearance of hypertrophic chondrocytes and new blood vessel formation. Areas of calcium deposits were surrounded by abundant hypertrophic chondrocytes (with marked immunoreactivity to TGF-beta and VEGF) and a significant number of TUNEL-positive chondrocytes. Calcium crystal deposition in the lumbar ligamentum flavum progresses with reduction in elastic fibers and accumulation of collagen fibrils in the matrix as well as expansion of chondrometaplastic areas.
authors.affiliation: Department of Orthopaedics and Rehabilitation Medicine, Fukui University Faculty of Medical Sciences, Shimoaizuki 23, Matsuoka, Fukui 910-1193, Japan. yayama@u-fukui.ac.jp
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yayama
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Sato
authors.forename: Kenzo
authors.initials: K
authors.lastname: Uchida
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kokubo
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nakajima
authors.forename: Takaharu
authors.initials: T
authors.lastname: Takamura
authors.forename: Erisa
authors.initials: E
authors.lastname: Mwaka
authors.forename: Norbert
authors.initials: N
authors.lastname: Orwotho
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Baba
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002131:Calcium Pyrophosphate / Q000378:metabolism*; D016022:Case-Control Studies; D003460:Crystallization; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D017843:Ligamentum Flavum / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D008159:Lumbar Vertebrae / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D013128:Spinal Osteophytosis / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D013168:Spondylolisthesis / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D042461:Vascular Endothelial Growth Factor A; D002131:Calcium Pyrophosphate