title: Meniscal degeneration in human knee osteoarthritis: in situ hybridization and immunohistochemistry study.
abstract: OBJECTIVE
  Meniscus injury is one of the causes of secondary osteoarthritis (OA). However, the role of meniscus is still unclear. Human meniscal distribution of cells and cartilage oligomeric matrix protein (COMP) and their changes in advanced OA were analyzed.
  
  
  METHODS
  Thirty-one medial menisci from patients with knee OA that underwent a total knee arthroplasty were studied. Normal meniscal tissue was obtained from partial arthroscopic meniscectomy. Meniscal samples were processed for histology, immunohistochemistry and in situ hybridization, for cell assessment including density, active divisions, apoptosis, COMP distribution and proteoglycan content.
  
  
  RESULTS
  Osteoarthritic menisci demonstrated areas of cell depletion and significant decrease in COMP immunostaining. Actively dividing cells were only found in the meniscectomy group, but not in the osteoarthritic group. Proteoglycan staining was less prominent in menisci from the osteoarthritis group.
  
  
  CONCLUSIONS
  Our results show a decreased cell population, with low COMP and altered matrix organization in osteoarthritis menisci that suggest an altered meniscal scaffold and potential impairment of meniscal function. These meniscal changes may be associated with the development of knee osteoarthritis.
authors.affiliation: Servicio de Cirugía Ortopédica y Traumatología, Hospital Infanta Sofía, Paseo de Europa, 34, 28702, San Sebastián de los Reyes, Madrid, Spain. lopezfranco_cot@yahoo.es.|Orthopaedic Surgery Department, Hospital Sur de Alcorcón, Madrid, Spain. lopezfranco_cot@yahoo.es.
authors.forename: Mariano
authors.initials: M
authors.lastname: López-Franco
authors.affiliation: Centro de Estudios y Servicios de Salud, Universidad Veracruzana, Veracruz, Mexico.
authors.forename: O
authors.initials: O
authors.lastname: López-Franco
authors.affiliation: Orthopaedic Surgery Department, Hospital Sur de Alcorcón, Madrid, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Murciano-Antón
authors.affiliation: Comparative Unit Pathology, Spanish National Research Centre, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Cañamero-Vaquero
authors.affiliation: Pathologic Anatomy Department, H Clínico San Carlos, Madrid, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Fernández-Aceñero
authors.affiliation: Rheumatology Department, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Herrero-Beaumont
authors.affiliation: Orthopaedic Surgery Department, Hospital La Paz, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Gómez-Barrena
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D019645:Arthroplasty, Replacement, Knee; D002114:Calcinosis / Q000473:pathology; D064236:Cartilage Oligomeric Matrix Protein / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008592:Menisci, Tibial / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology* / Q000601:surgery; D011509:Proteoglycans / Q000378:metabolism
chemical_list: D064236:Cartilage Oligomeric Matrix Protein; D011509:Proteoglycans
keywords: COMP; Immunohistochemistry; In situ hybridization; Knee osteoarthritis; Meniscus