title: Persisting high levels of synovial fluid markers after cartilage repair: a pilot study.
abstract: Local attempts to repair a cartilage lesion could cause increased levels of anabolic and catabolic factors in the synovial fluid. After repair with regenerated cartilage, the homeostasis of the cartilage ideally would return to normal. In this pilot study, we first hypothesized levels of synovial fluid markers would be higher in patients with cartilage lesions than in patients with no cartilage lesions, and then we hypothesized the levels of synovial fluid markers would decrease after cartilage repair. We collected synovial fluid samples from 10 patients before autologous chondrocyte transplantation of the knee. One year later, a second set of samples was collected and arthroscopic evaluation of the repair site was performed. Fifteen patients undergoing knee arthroscopy for various symptoms but with no apparent cartilage lesions served as control subjects. We measured synovial fluid matrix metalloproteinase-3 (MMP-3) and insulinlike growth factor-I (IGF-I) concentrations with specific activity and enzyme-linked immunosorbent assays, respectively. The levels of MMP-3 and IGF-I were higher in patients having cartilage lesions than in control subjects with no cartilage lesions. One year after cartilage repair, the lesions were filled with repair tissue, but the levels of MMP-3 and IGF-I remained elevated, indicating either graft remodeling or early degeneration.
  
  
  METHODS
  Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors: Department of Orthopaedics and Traumatology, Helsinki University Hospital, Peijas Hospital, Helsinki, Finland. anna.vasara@fimnet.fi
authors: Anna I
authors: AI
authors: Vasara
authors: Yrjö T
authors: YT
authors: Konttinen
authors: Lars
authors: L
authors: Peterson
authors: Anders
authors: A
authors: Lindahl
authors: Ilkka
authors: I
authors: Kiviranta
mesh_terms: D000293:Adolescent; D000328:Adult; D001182:Arthroscopy; D015415:Biomarkers / Q000378:metabolism*; D001847:Bone Diseases / Q000378:metabolism / Q000601:surgery; D019902:Chondrocytes / Q000637:transplantation*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007718:Knee Injuries / Q000378:metabolism / Q000601:surgery*; D008297:Male; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D008592:Menisci, Tibial / Q000378:metabolism* / Q000601:surgery*; D008875:Middle Aged; D010865:Pilot Projects; D011379:Prognosis; D013582:Synovial Fluid / Q000378:metabolism*; D000070600:Tibial Meniscus Injuries; D014182:Transplantation, Autologous; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007334:Insulin-Like Growth Factor I; D019278:Matrix Metalloproteinase 3