title: Synovial cytokine expression in ankle osteoarthritis depends on age and stage.
abstract: OBJECTIVE
  Aim of the study was the analysis of cytokine expression in ankle osteoarthritis (OA) hypothesizing age-dependent regulation patterns.
  
  
  METHODS
  Forty-nine patients undergoing an arthroscopy of the ankle with different stages of chronic OA were prospectively included in a clinical trial comparing the group <18 years (n = 9, Ø15.1 ± 2.0 years) with the older patients (≥18 years, n = 40, Ø36.5 ± 11.9). Lavage fluids were analysed by ELISA for levels of aggrecan, BMP-2/7, IGF-1/R, bFGF, CD105, MMP-13, and IL-1β. Additionally, clinical parameters and scores (FFI, CFSS, AOFAS) were evaluated and supplemented by radiographic scores [Kellgren-Lawrence Score (KLS) for conventional X-rays, Ankle Osteoarthritis Scoring System (AOSS) for MRI].
  
  
  RESULTS
  In contrast to distribution of gender and BMI (p < 0.005), parameters characterizing the cartilage defect as ICRS grading, size, and duration of symptoms were not dependent on age. The incidence of osteochondritis dissecans (OCD) was higher in the group <18 years (p < 0.006), but the average degree of OCD grading was not different. KLS and AOSS were significantly higher in the group ≥18 years (p < 0.02). Correlating with the higher degree of OA in the elderly, clinical function measured by FFI and AOFAS was statistically significantly worse (p < 0.05). Intra-articular concentrations of aggrecan (3.1-fold), bFGF (8.7-fold), BMP-7 (2.7-fold), and CD105 (1.5-fold) were statistically significantly higher in the group ≥18 years (p < 0.03).
  
  
  CONCLUSIONS
  Confirming the hypothesis, increased synovial levels of aggrecan, bFGF, BMP-7, and CD105 were found in patients over 18 years. This correlated with a higher stage of OA determined by radiographic changes or deteriorated function and may offer starting points for new diagnostics and interventional strategies.
  
  
  METHODS
  II.
authors.affiliation: Department of Orthopaedic Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg i.Br., Germany. hagen.schmal@freenet.de.
authors.forename: Hagen
authors.initials: H
authors.lastname: Schmal
authors.affiliation: Department of Orthopaedic Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg i.Br., Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Henkelmann
authors.affiliation: Department of Orthopaedic Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg i.Br., Germany.
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Mehlhorn
authors.affiliation: Department of Orthopaedic Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg i.Br., Germany.
authors.forename: Kilian
authors.initials: K
authors.lastname: Reising
authors.affiliation: Department of Orthopaedic Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg i.Br., Germany.
authors.forename: Gerrit
authors.initials: G
authors.lastname: Bode
authors.affiliation: Department of Orthopaedic Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg i.Br., Germany.
authors.forename: Norbert P
authors.initials: NP
authors.lastname: Südkamp
authors.affiliation: Department of Orthopaedic Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, 79106, Freiburg i.Br., Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Niemeyer
mesh_terms: D000328:Adult; D000375:Aging / Q000378:metabolism*; D000842:Ankle; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D001182:Arthroscopy; D016207:Cytokines / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D011446:Prospective Studies; D011859:Radiography; D013582:Synovial Fluid / Q000378:metabolism*
chemical_list: D016207:Cytokines