Classification of osteoarthritis

Osteoarthritis is a common cartilage condition and a major cause of pain and disability in older adults. Primary osteoarthritis results from changes over time often linked to factors such as age, obesity, and a family history of osteoarthritis. Secondary osteoarthritis is caused by other conditions that damage cartilage.¹

**Types of osteoarthritis**
Primary osteoarthritis	Secondary osteoarthritis
It is usually limited to one or a small number of joints.	It may be limited to a small number of joints if injury-related, or it may be in joints throughout body if disease-related.
It is seen in spine, thumbs, knees and top two sets of finger joints.	It is seen in wrists, shoulders, ankles, and the middle set of finger joints.
No specific inflammatory or metabolic condition known to be associated with arthritis is present.	Conditions that cause damage to cartilage may be present, such as: Inherited diseases of iron, calcium, or copper storage, such as hemochromatosis, hyperparathyroidism, or Wilson's disease. Neurologic disorders that result in the loss of nerve function. Congenital diseases that cause an imbalance in the joints. Bone disorders that affect joints.
There is no history of specific injury or trauma.	There may be a history of injury to joints, such as fractures and tears, or history of trauma to joints, such as repetitive heavy lifting or kneeling.

References

Citations

Wise C (2005). Osteoarthritis. In DC Dale, DD Federman, eds., ACP Medicine, section 15, chap. 10. New York: WebMD.

Credits

Author	Robin Parks, MS
Editor	Kathleen M. Ariss, MS
Associate Editor	Pat Truman, MATC
Primary Medical Reviewer	E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer	Stanford M. Shoor, MD - Rheumatology
Last Updated	April 20, 2007