Osteoarthritis is an important cause of disability in our society, affecting millions and resulting in limitations on activity. It is primarily a disease of articular cartilage, either from distant injury or degeneration. However many other changes are seen in additional tissues about the knee. Imaging offers a noninvasive means of assessing the degree of damage to the knee joint and the effectiveness of therapy or behavior modification.
Many imaging methods are available to assess the degenerative knee. Conventional radiography can be used to detect gross loss of cartilage and other soft tissues, evident as narrowing of the distance between the bony components of the joint, but it does not image soft tissue directly.1 Secondary changes such as osteophyte formation can be seen, but conventional radiography is insensitive to early chondral and meniscal damage. Fractures, as in the case of an osteochondral defect, can be detected with limited sensitivity, but chondral defects or cartilage delamination cannot be seen. Arthrography, alone or combined with conventional radiography, CT scanning, or MR imaging, is mildly invasive and provides information limited to the contour of the cartilage surface…
Marrow Edema
Bone marrow edema is an indication that the bone has been subjected to stress, and may be the result of trauma or tissue stress that exceeds the ability of the overlying tissue to protect the subchondral…
Cartilage in the Degenerative Knee
High-grade cartilage lesions that have been present for a while often have areas of overlying marrow edema. Fast spin-echo…
Meniscal Tears and Extrusion
Damage to the knee meniscus may precede or follow damage to the articular cartilage in osteoarthritis. In cases of osteoarthritis, the meniscus is often…
Osteophytes
Osteophyte formation is common in osteoarthritis, and osteophytes are frequently seen on…
Joint Bodies and Subchondral Cysts
Bodies in the synovial joint are frequently calcified and filled with fatty marrow. Detection of these bodies can be difficult on MRI, and comparison with…
Conclusion
This article was edited from MR Imaging of the Degenerative Knee by the same author. The complete unabridged version, including all of its images and references, is available at the Apple iBooks Store. See other MSK and Joint articles here.
REFERENCES
- Hunter DJ, Guermazi A. Imaging techniques in osteoarthritis. PM R. 2012 May;4(5 Suppl):S68-74.
- Wick MC, Jaschke W, Klauser AS. Radiological imaging of osteoarthritis of the knee. Radiologe. 2012 Oct 7.