|Arthropathy means joint disease. The disease may be localized to one joint, as with post-traumatic arthritis, or may affect multiple joints, as with osteoarthritis or rheumatoid arthritis. It may also be due to an underlying condition such as a bacterial infection (infectious, pyogenic, or septic arthritis). Neuropathic arthropathy refers to bone and joint changes that develop secondary to loss of sensation associated with various disorders, including diabetes, trauma, infection, pernicious anemia, spina bifida, or amyloidosis. Arthropathy is frequently associated with articular trauma, joint slippage (subluxation) and instability, or degenerative changes of the joint. The most common form of arthropathy is osteoarthritis, in which there is progressive loss of articular joint cartilage with reactive changes at the joint margins and subchondral bone, resulting in joint destruction. |
In fully developed arthropathy, joint destruction is accompanied by enlargement of the joint from swelling caused by synovial fluid joint effusion, and the development of bony overgrowth at the joint margins (osteophyte formation). Eventually, joint deformity increases as microfractures, ligamentous looseness (laxity), and decreased muscular support occur. Increased joint laxity and periarticular fractures may also result in small pieces of bone or cartilage (loose bodies) that fragment into the joint. This may result in a grating or grinding noise when the joint is moved (crepitus), although crepitus also has other causes.
Arthropathy may be the result of degenerative joint diseases such as facet joint arthropathy or knee osteoarthritis; bleeding into a joint (intra-articular hemorrhage) from trauma or hemophilia; neuropathic arthropathy secondary to diabetes or Charcot-Marie Tooth disease (Charcot joint); inflammatory joint disorders such as rheumatoid arthritis and ankylosing spondylitis; autoimmune disorders such as ulcerative colitis, Crohn's disease, systemic lupus erythematosus, and polymyalgia; septic disorders such as osteomyelitis and septic arthritis caused by bacterial or fungal infections; and crystal-depositing disorders such as gout or pseudogout.
Degenerative arthropathy may occur as the result of a single trauma to the joint, such as an acute shoulder dislocation or as the result of a healed fracture that occurred in or around the joint (intra-articular, periarticular fracture), in which case it is called post-traumatic arthritis. It can also occur secondary to malunion of a nearby fracture that results in altered biomechanics of the joint.
Neuropathic arthropathy is the rapid destruction of joints due to a loss of sensation associated with certain diseases, resulting in impaired position sense and pain perception. Although the exact pathophysiology of neuropathic arthropathy is not known, joint destruction appears to develop when the individual who has lost deep sensation is unable to feel multiple small episodes of joint trauma that occur with certain conditions. Among conditions that are most likely to result in neuropathic arthropathy are diabetes mellitus with diabetic neuropathy, syringomyelia, spinal cord and peripheral nerve tumors, and Charcot-Marie Tooth disease. Almost any joint may be affected by neuropathic arthropathy, depending upon the underlying disease, but the knee joint is involved most frequently. Usually one to three joints are affected, normally in an asymmetrical distribution.
Gout and other crystal-associated arthropathies are caused by the deposition of monosodium urate (MSU), calcium pyrophosphate dehydrate (CPPD), calcium apatite, and calcium oxylate crystals, inducing acute or chronic osteoarthritis or periarthritis. MSU (gout) and CPPD crystal deposition (pseudogout) may also lead to degenerative arthropathy via repeated, intermittent attacks of acute arthritis. This frequently occurs in large, peripheral joints, particularly in the lower extremity.
Joint damage resulting in arthropathy may occur from the inflammatory reaction of infectious arthritis. The joint may become infected via surgery, injection, insect or animal bite, trauma, abscess, osteomyelitis, or sepsis.
Individuals with diabetes or any underlying degenerative joint conditions are more likely to develop arthropathy.
Risk: Osteoarthritis is the most common type of arthropathy. It is more common in those over age 40 years and is a leading cause of disability in individuals over age 65 years (Moses). Between the ages of 40 and 70, women are more troubled with osteoarthritis than men; after age 70, the rates are the same (Brandt; Porter).
Incidence and Prevalence: The exact incidence of multiple arthropathies is not known because occurrence of arthropathy is so often secondary to an underlying disease. Osteoarthritis affects over 20 million individuals in the US and is the most common articular disease worldwide (Lozada). The incidence of rheumatoid arthritis is 1% in US and global populations (Smith). The overall incidence of neuropathic arthropathy is not known, but neuropathic arthropathy associated with diabetes is estimated at 15% of diabetic patients in the US and worldwide (Khan).