title: Hypertrophy of the ligamentum flavum in lumbar spinal canal stenosis is associated with increased bFGF expression.
abstract: OBJECTIVE
  A prospective study was undertaken to investigate basic fibroblast growth factor (bFGF) expression in hypertrophic ligamentum flavum (LF) from patients with lumbar spinal canal stenosis (LSCS) and to determine whether there was a correlation of bFGF expression with LF thickness.
  
  
  METHODS
  Twenty patients with lumbar spinal canal stenosis were enrolled in this study. bFGF mRNA and protein expressions in LF were analyzed using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA), respectively. The thickness of LF was measured by axial T1-weighted magnetic resonance imaging.
  
  
  RESULTS
  Expression of bFGF was substantially higher in the hypertrophic LF group than in the control group (P < 0.001) as quantified by quantitative real-time PCR. In immunohistochemical study, bFGF was positively stained on the fibroblasts within hypertrophic LF compared to nonpathologic LF of controls. Subsequent ELISA analysis revealed that bFGF concentration in the hypertrophic LF group was remarkably higher than that in the control group (P = 0.003). The thickness of LF in the hypertrophic LF was significantly greater than that in the control group (P < 0.001). LSCS patients with greater severity of LF hypertrophy had significantly higher bFGF levels in the LF tissues (P < 0.001). Furthermore, the bFGF concentration exhibited a positive correlation with the LF thickness (r = 0.974, P < 0.001).
  
  
  CONCLUSIONS
  These findings suggest that the increased expression of bFGF is associated with the hypertrophy of ligamentum flavum in patients with LSCS.
authors.affiliation: Department of Orthopaedics, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Rama IV road, Patumwan, Bangkok 10330, Thailand. sittisak.h@chula.ac.th
authors.forename: Sittisak
authors.initials: S
authors.lastname: Honsawek
authors.forename: Jariya
authors.initials: J
authors.lastname: Poonpukdee
authors.forename: Chookiet
authors.initials: C
authors.lastname: Chalermpanpipat
authors.forename: Sunchai
authors.initials: S
authors.lastname: Payungporn
authors.forename: Worawat
authors.initials: W
authors.lastname: Limthongkul
authors.forename: Wicharn
authors.initials: W
authors.lastname: Yingsakmongkol
authors.forename: Voranuch
authors.initials: V
authors.lastname: Thanakit
authors.forename: Vinai
authors.initials: V
authors.lastname: Parkpian
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D006801:Humans; D006984:Hypertrophy; D007150:Immunohistochemistry; D017843:Ligamentum Flavum / Q000378:metabolism* / Q000473:pathology*; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012333:RNA, Messenger / Q000378:metabolism; D012720:Severity of Illness Index; D013130:Spinal Stenosis / Q000378:metabolism / Q000473:pathology*
chemical_list: D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2