Meniscal body extrusion and cartilage coverage in middle-aged and elderly without radiographic knee osteoarthritis

Research output: Contribution to journalArticle


Objectives: To determine meniscal extrusion and cartilage coverage on magnetic resonance (MR) images and factors associated with these parameters in knees of middle-aged and elderly persons free from radiographic tibiofemoral osteoarthritis (OA). Methods: Seven hundred eighteen persons, free of radiographic tibiofemoral OA, aged 50–90 years from Framingham, MA, USA, were included. We measured meniscal extrusion on 1.5 T MRI of both knees to evaluate both medial and lateral meniscal body extrusion and cartilage coverage. We also determined meniscal morphology and structural integrity. The multivariable association with age, body mass index (BMI), and ipsilateral meniscal damage was also evaluated. Results: The mean meniscal body extrusion medially was 2.7 mm and laterally 1.8 mm. The tibial cartilage coverage was about 30% of ipsilateral cartilage surface (both compartments). The presence of ipsilateral meniscal damage was associated with more extrusion in only the medial compartment, 1.0 mm in men and 0.6 mm in women, and less cartilage coverage proportion, -5.5% in men and -4.6% in women. Conclusions: Mean medial meniscal body extrusion in middle-aged or older persons without radiographic tibiofemoral OA approximates the commonly used cutoff (3 mm) to denote pathological extrusion. Medial meniscal damage is a factor associated with medial meniscal body extrusion and less cartilage coverage. Key Points: • Medial meniscal extrusion in middle-aged/older persons without OA is around 3 mm. • Lateral meniscal extrusion in middle-aged/older persons without OA is around 2 mm. • Meniscal damage is associated with medial meniscal extrusion and less cartilage coverage.


External organisations
  • Boston University
  • Friedrich-Alexander University Erlangen-Nürnberg
  • Brigham and Women's Hospital / Harvard Medical School
  • Harvard University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Orthopedics
  • Radiology, Nuclear Medicine and Medical Imaging


  • Coverage, Knee, Magnetic resonance imaging, Meniscus, Osteoarthritis
Original languageEnglish
Pages (from-to)1848-1854
JournalEuropean Radiology
Issue number4
Early online date2018 Oct 2
Publication statusPublished - 2019
Publication categoryResearch

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