Qualitative radiographic diagnosis of osteo-arthritis of the knee joint in the C57BL mouse.

Experiments were performed to assess the diagnostic value of radiography in osteo-arthritis (OA) of the knee joint in C57Bl mice. Comparative histological and radiographic examination of knee joints from 96 animals showed that if the classical diagnostic criteria (narrowing of the joint space, sclerosis of the subchondral bone, deformation of the joint epiphyses) are applied, OA is not readily detectable by radiography. If these criteria are extended to include radiographic changes in the menisci (enlargement, deformation, increased and/or heterogeneous density), the frequency of detection is much improved. However, except in the severest forms of OA, radiography does not afford a satisfactory means of distinguishing between various degrees of severity. The qualitatively evaluated data nevertheless do suggest that quantitative radiographic diagnosis of OA of the murine knee joint may be useful, both for improving the detection rate and for discriminating various degrees of OA.