title: Quantitative measures of meniscus extrusion predict incident radiographic knee osteoarthritis--data from the Osteoarthritis Initiative.
abstract: OBJECTIVE
  To test the hypothesis that quantitative measures of meniscus extrusion predict incident radiographic knee osteoarthritis (KOA), prior to the advent of radiographic disease.
  
  
  METHODS
  206 knees with incident radiographic KOA (Kellgren Lawrence Grade (KLG) 0 or 1 at baseline, developing KLG 2 or greater with a definite osteophyte and joint space narrowing (JSN) grade ≥1 by year 4) were matched to 232 control knees not developing incident KOA. Manual segmentation of the central five slices of the medial and lateral meniscus was performed on coronal 3T DESS MRI and quantitative meniscus position was determined. Cases and controls were compared using conditional logistic regression adjusting for age, sex, BMI, race and clinical site. Sensitivity analyses of early (year [Y] 1/2) and late (Y3/4) incidence was performed.
  
  
  RESULTS
  Mean medial extrusion distance was significantly greater for incident compared to non-incident knees (1.56 mean ± 1.12 mm SD vs 1.29 ± 0.99 mm; +21%, P < 0.01), so was the percent extrusion area of the medial meniscus (25.8 ± 15.8% vs 22.0 ± 13.5%; +17%, P < 0.05). This finding was consistent for knees restricted to medial incidence. No significant differences were observed for the lateral meniscus in incident medial KOA, or for the tibial plateau coverage between incident and non-incident knees. Restricting the analysis to medial incident KOA at Y1/2 differences were attenuated, but reached significance for extrusion distance, whereas no significant differences were observed at incident KOA in Y3/4.
  
  
  CONCLUSIONS
  Greater medial meniscus extrusion predicts incident radiographic KOA. Early onset KOA showed greater differences for meniscus position between incident and non-incident knees than late onset KOA.
authors: Institute of Anatomy, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Department of Orthopedics, BHS Linz, Linz, Austria. Electronic address: katja.emmanuel@bhs.at.
authors: K
authors: K
authors: Emmanuel
authors: Clinical Epidemiology Research & Training Unit, Boston University School of Medicine, Boston, MA, USA.
authors: E
authors: E
authors: Quinn
authors: Clinical Epidemiology Research & Training Unit, Boston University School of Medicine, Boston, MA, USA.
authors: J
authors: J
authors: Niu
authors: Quantitative Imaging Center (QIC), Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Boston Imaging Core Lab (BICL), Boston, MA, USA.
authors: A
authors: A
authors: Guermazi
authors: Quantitative Imaging Center (QIC), Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: F
authors: F
authors: Roemer
authors: Institute of Anatomy, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Chondrometrics GmbH, Ainring, Germany.
authors: W
authors: W
authors: Wirth
authors: Institute of Anatomy, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Chondrometrics GmbH, Ainring, Germany.
authors: F
authors: F
authors: Eckstein
authors: Clinical Epidemiology Research & Training Unit, Boston University School of Medicine, Boston, MA, USA; NIHR Biomedical Research Unit at the University of Manchester, Manchester, UK.
authors: D
authors: D
authors: Felson
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D054850:Osteophyte / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography
keywords: Incident knee osteoarthritis; Meniscus extrusion; Meniscus position; Meniscus position risk factor for knee osteoarthritis