title: Differences in levels of inflammatory mediators in meniscal and synovial tissue of patients with meniscal lesions.
abstract: BACKGROUND
  Meniscal injuries are a risk factor for osteoarthritis (OA). While a mechanical pathway between meniscal injury and OA has been described, the biological effects of inflammation on this pathway have yet to be clarified. The aim of our study was to compare levels of specific inflammatory mediators, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nerve growth factor (NGF), in injured and uninjured meniscal tissue and related knee joint synovium.
  
  
  METHODS
  Tissue samples were obtained from 19 patients, 31.1 ± 13.6 years old, who underwent arthroscopic partial meniscectomy. For analysis, tissue samples were categorized into the following groups: injured meniscal site (IM), non-injured meniscal site (NIM), synovium 'nearest' the lesion (NS), and synovium from the opposite knee compartment, 'farthest' synovium (FS). Levels of inflammatory mediators were determined using enzyme-linked immunosorbent assay and between-group differences (IM and NIM; NS and FS) were evaluated using the Wilcoxon signed-rank test. The association between pre-operative pain score and the level of each inflammatory mediator was evaluated using Spearman's correlation.
  
  
  RESULTS
  Higher levels of TNF-α and IL-6 were identified in the IM tissue, compared to NIM (p <0.05). IL-6 levels were also higher in the NS compared to the FS (p <0.05). There was no correlation between pre-operative pain score and level of each inflammatory mediator.
  
  
  CONCLUSIONS
  Our outcomes confirm a local increase in inflammatory mediator levels, in both meniscal and synovial tissue, which could contribute to development of OA. Management of these biological effects of meniscal injury might be warranted.
authors.affiliation: Funabashi Orthopaedic Hospital Sports Medicine Center, Funabashi, Chiba, Japan. togura@fff.or.jp.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ogura
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. miyako_rush634@yahoo.co.jp.
authors.forename: Miyako
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. sakuma-cib@umin.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakuma
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. kyamauchi@chiba-u.jp.
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Yamauchi
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. sorita@chiba-u.jp.
authors.forename: Sumihisa
authors.initials: S
authors.lastname: Orita
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. masayuki008@aol.com.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyagi
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. ishikawa_tetsuhiro@yahoo.co.jp.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. kamodahiroto@gmail.com.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kamoda
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. y.oikawa-1979@hotmail.co.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Oikawa
authors.affiliation: Funabashi Orthopaedic Hospital Sports Medicine Center, Funabashi, Chiba, Japan. kanisawa@fff.or.jp.
authors.forename: Izumi
authors.initials: I
authors.lastname: Kanisawa
authors.affiliation: Funabashi Orthopaedic Hospital Sports Medicine Center, Funabashi, Chiba, Japan. ktakahashi@fff.or.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Funabashi Orthopaedic Hospital Sports Medicine Center, Funabashi, Chiba, Japan. hsakai@fff.or.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sakai
authors.affiliation: Funabashi Orthopaedic Hospital Sports Medicine Center, Funabashi, Chiba, Japan. t-naga@sirius.ocn.ne.jp.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Nagamine
authors.affiliation: Funabashi Orthopaedic Hospital Sports Medicine Center, Funabashi, Chiba, Japan. hfukuda@fff.or.jp.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Fukuda
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. 19501114@faculty.chiba-u.jp.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. sohtori@faculty.chiba-u.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohtori
authors.affiliation: Funabashi Orthopaedic Hospital Sports Medicine Center, Funabashi, Chiba, Japan. a-tsuchiya@fff.or.jp.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tsuchiya
keywords: Inflammatory mediator; Meniscal injury; Osteoarthritis; Synovium