Imaging of Musculoskeletal Disorders Osteoarthritis
Key features of osteoarthritis
Joint space narrowing
Osteophytes
Articular irregularity and/or sclerosis
Sub-cortical cysts (geodes)
Intra-articular loose bodies
Note: Erosions are NOT a feature
Osteoarthritis can affect any synovial joint. The hands, wrists, hips, knees, and feet are most commonly involved.
Osteoarthritis results in characteristic X-ray appearances including joint space narrowing, formation of osteophytes (bone spurs), articular surface cortical irregularity and/or sclerosis, and formation of sub-cortical cysts (geodes).
These features can be seen in isolation but commonly two or more signs are present.
Note: Erosions are not a feature of osteoarthritis and if seen should raise the suspicion of an inflammatory arthritis such as rheumatoid arthritis.
Although sub-cortical bone cysts are a characteristic finding of osteoarthritis, they are only visible in approximately one third of X-rays of osteoarthritic joints
This hip joint is narrowed and large osteophytes have formed
Note: These cysts may be called ‘sub-chondral cysts’, ‘sub-cortical cysts’, or 'geodes' – any of these terms are acceptable
Large osteophytes (arrowheads) have formed at the joints of the fingers
These osteophytes correspond to the clinical finding of bony swelling at the distal interphalangeal joints (Heberden’s nodes) and the proximal interphalangeal joints (Bouchard’s nodes)
The joints are severely narrowed (arrows)
Large sub-cortical cysts have also formed in this patient with severe osteoarthritis of the finger joints
