MR imaging of erosions in interphalangeal joint osteoarthritis: is all osteoarthritis erosive?

Skeletal Radiol. 2007 Aug;36(8):737-45. doi: 10.1007/s00256-007-0287-5. Epub 2007 May 12.


Objective: Erosive osteoarthritis is usually considered as an inflammatory subset of osteoarthritis (OA). However, an inflammatory component is now recognised in all subsets of OA, so this subgroup of erosive or inflammatory OA is more difficult to conceptualise. The aim of this study was to compare routine CR and MRI to investigate erosion numbers and morphology to determine whether hand OA in general is a more erosive disease than previously recognised.

Design and methods: Fifteen patients with clinical (OA) of the small joints of the hand underwent MRI of one of the affected proximal interphalangeal (PIP) or distal interphalangeal (DIP) joints. Conventional radiographs (CR) of the hand were also obtained. The MR images were reviewed by two observers for the presence of central and marginal erosions. The site and morphology of any erosions was recorded. CR images of the same hand joint were scored independently for central and marginal erosions by the same observers.

Results: There was 100% agreement between the observers for scoring erosions on CR. Agreement for the MRI scores was also excellent (kappa = 0.84). MRI detected 37 erosions, of which only 9 were seen on CR. The increase in sensitivity using MRI was much greater for marginal erosions (1 detected on CR, 19 on MRI) than for central erosions (8 on CR, 18 on MRI). Using MRI 80% of joints examined showed 1 or more erosions compared with 40% using CR. If only marginal erosions were considered 80% of joints were still considered erosive by MRI criteria, but only 1 showed evidence of erosion on CR. Morphologically central erosions appeared to represent areas of subchondral collapse and pressure atrophy. In contrast, marginal erosions resembled those seen in inflammatory arthritides.

Conclusion: Erosions, and particularly marginal erosions typical of those seen in inflammatory arthritis, are a more common feature of small joint OA than conventional radiographs have previously indicated.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Contrast Media / administration & dosage
  • Disease Progression
  • Female
  • Finger Joint / diagnostic imaging
  • Finger Joint / pathology*
  • Gadolinium DTPA
  • Humans
  • Image Enhancement / methods
  • Imaging, Three-Dimensional
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Imaging / statistics & numerical data*
  • Male
  • Middle Aged
  • Observer Variation
  • Osteoarthritis / diagnosis*
  • Predictive Value of Tests
  • Radiography
  • Sensitivity and Specificity
  • Severity of Illness Index


  • Contrast Media
  • Gadolinium DTPA