Videoradiographic analysis of the range of motion in unilateral experimental knee joint arthritis in rats

Arthritis Res Ther. 2011 May 27;13(3):R79. doi: 10.1186/ar3342.


Introduction: The translational and predictive value of animal models highly depends on the validity of respective readout parameters. In arthritis research, there has been a shift from sole threshold testing for pain-related behavior, as well as from swelling and histology assessment for inflammation, toward an analysis of joint function as indicated, for instance, by an increasing number of studies on gait abnormalities. Clinically, the range of motion (ROM) of the affected joint plays a major role in diagnosis and the assessment of treatment benefits. This parameter, however, is only insufficiently detected by currently used analytic systems in animals.

Methods: Here we used high-resolution videoradiographic analysis to assess ROM in experimental knee joint arthritis in rats. This parameter is described during the 21-day course of antigen-induced arthritis in rats. Furthermore, the therapeutic effects of antinociceptive (morphine) and anti-inflammatory (dexamethasone) treatment on ROM are documented. To obtain additional information on the implications of ROM in animal models, correlations were performed to measure pain-related behavior and inflammation.

Results: The study animals showed a significant reduction in ROM of the inflamed knee joint in the acute phase of arthritis. This was accompanied by an increase in knee joint movement on the contralateral side, indicating a compensational mechanism. Both morphine and dexamethasone treatment increased and thus normalized ROM. Changes in ROM were further stage-dependently correlated with weight bearing and joint swelling, that is, with both pain-related behavior and signs of inflammation.

Conclusions: The dynamic ROM observed in freely moving rats in our model of knee joint arthritis might serve as a parameter for global disease activity and might thus represent a promising readout parameter for preclinical assessment regarding the overall efficacy not only of antiarthritic but also of antinociceptive compounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesics, Opioid / pharmacology
  • Anatomic Landmarks / diagnostic imaging
  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Arthralgia / diagnostic imaging
  • Arthralgia / drug therapy
  • Arthralgia / physiopathology
  • Arthritis, Experimental / diagnostic imaging*
  • Arthritis, Experimental / drug therapy
  • Arthritis, Experimental / physiopathology
  • Arthrography / instrumentation
  • Arthrography / methods*
  • Arthrography / standards
  • Dexamethasone / pharmacology
  • Disease Models, Animal
  • Female
  • Knee Joint / diagnostic imaging*
  • Knee Joint / physiopathology
  • Morphine / pharmacology
  • Motor Activity / physiology
  • Predictive Value of Tests
  • Range of Motion, Articular / physiology*
  • Rats
  • Rats, Inbred Lew
  • Reproducibility of Results
  • Video Recording / instrumentation
  • Video Recording / methods*
  • Video Recording / standards


  • Analgesics, Opioid
  • Anti-Inflammatory Agents
  • Morphine
  • Dexamethasone