title: A Porcine Animal Model for Early Meniscal Degeneration - Analysis of Histology, Gene Expression and Magnetic Resonance Imaging Six Months after Resection of the Anterior Cruciate Ligament.
abstract: OBJECTIVE
  The menisci of the mammalian knee joint balance the incongruence between femoral condyle and tibial plateau and thus menisci absorb and distribute high loads. Degeneration processes of the menisci lead to pain syndromes in the knee joint. The origin of such degenerative processes on meniscal tissue is rarely understood and may be described best as an imbalance of anabolic and catabolic metabolism. A standardized animal model of meniscal degeneration is needed for further studies. The aim of the current study was to develop a porcine animal model with early meniscal degeneration.
  
  
  METHODS
  Resection of the anterior cruciate ligament (ACLR) was performed on the left knee joints of eight Göttingen minipigs. A sham operation was carried out on the right knee joint. The grade of degeneration was determined 26 weeks after the operation using histology and magnetic resonance imaging (MRI). Furthermore, the expression of 14 genes which code for extracellular matrix proteins, catabolic matrix metalloproteinases and inflammation mediators were analyzed.
  
  
  RESULTS
  Degenerative changes were detected by a histological analysis of the medial meniscus after ACLR. These changes were not detected by MRI. In terms of their gene expression profile, these degenerated medial menisci showed a significantly increased expression of COL1A1.
  
  
  CONCLUSIONS
  This paper describes a new animal model for early secondary meniscal degeneration in the Göttingen minipig. Histopathological evidence of the degenerative changes could be described. This early degenerative changes could not be seen by NMR imaging.
authors.affiliation: Department of Experimental Orthopedics and Trauma Surgery, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.|Department of Molecular Cell Biology, University Medical Centre Homburg, Saarland University, Homburg/Saar, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kreinest
authors.affiliation: Department of Experimental Orthopedics and Trauma Surgery, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Reisig
authors.affiliation: Department of Pathology, University Medical Centre Göttingen, Göttingen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Ströbel
authors.affiliation: Department of Radiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Dinter
authors.affiliation: Department of Radiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Attenberger
authors.affiliation: Department of Molecular Cell Biology, University Medical Centre Homburg, Saarland University, Homburg/Saar, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Lipp
authors.affiliation: Department of Experimental Orthopedics and Trauma Surgery, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schwarz
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D034421:Sus scrofa; D013552:Swine; D013556:Swine, Miniature; D013977:Tibia / Q000503:physiopathology / Q000601:surgery; D000070600:Tibial Meniscus Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*