Osteoarthritis
(OA), also known as degenerative joint disease (DJD), is a process
of progressive deterioration of articular cartilage and formation of new bone
(osteophytes) at the joint surface. Primary osteoarthritis is age related
and associated with repetitive and/or high mechanical stress on a normal joint.
Secondary osteoarthritis is due to an underlying cause such as trauma, inflammatory,
metabolic, developmental, or connective tissue diseases.
Distribution:
Primary osteoarthritis of the hands typically targets the PIP, DIP,
scaphotrapeziotrapezoid and the 1st carpometacarpal joints. The knee, hip,
spinal, and 1st metatarsophalangeal joints are other areas which are commonly
involved. Additional joints can be affected in cases of secondary osteoarthritis.
Radiographic Findings: Affected joint spaces are narrowed with reactive
subchondral sclerosis (eburnation). Other classic radiographic findings include
osteophytes and subchondral cysts. Heberden's nodes at the DIP joints and
Bouchard's nodes at the PIP joints of the hands are areas of osteophyte formation
and soft tissue swelling associated with osteoarthritis. Intraarticular loose
bodies can also sometimes be seen. Erosive osteoarthritis is an inflammatory
arthritis primarily seen in peri- and post-menopausal women; the distribution
pattern in the hands is the same as in primary osteoarthritis. However, this
process is associated with osteoporotic changes and erosions at the center
of the involved articular surfaces which create a "gull-wing" deformity.
Differential: Erosive osteoarthritis of the hands can sometimes be mistaken for psoriatic arthritis, rheumatoid arthritis, or hemochromatosis. The distinguishing feature which may help to differentiate erosive OA from the other diseases is its involvement of the 1st carpometacarpal (trapeziometacarpal) joint. Primary osteoarthritis can be differentiated from rheumatoid arthritis by its lack of marginal erosions, and uniformity in joint space narrowing at the small hand joints; furthermore, RA rarely involves the DIP joints. Conditions which are associated with secondary osteoarthritis will often have radiographic findings related to the primary process. This may include diseases such as hyperparathyroidism, hemachromatosis, rheumatoid arthritis, etc. is a collagen vascular disease of unknown etiology otherwise known as progressive systemic sclerosis. There is a generalized disorder of the microvasculature which causes and vascular compromise of the skin and other organ systems. It is three to four times more common in women than men.
