Osteoarthritis Health Article

Primary osteoarthritis

Primary OA results from abnormal stress on weight-bearing joints, or normal stress affecting weakened joints. Primary OA most frequently affects the finger joints, the hips and knees, the cervical and lumbar spine, and the big toe. Some gene mutations appear to be associated with OA. Obesity also increases the pressure on the weight-bearing joints of the body. Finally, as the body ages, there is a reduction in the ability of cartilage to repair itself. In addition to these factors, some researchers have theorized that primary OA may be triggered by enzyme disturbances, bone disease, or liver dysfunction.

Secondary osteoarthritis

Secondary OA results from chronic or sudden injury to a joint. It can occur in any joint. Secondary OA is associated with the following factors:

• trauma to the body, including sports injuries
• repetitive stress injuries associated with certain occupations (i.e., the performing arts, construction or assembly line work, computer keyboard operation, etc.)
• repeated episodes of gout or septic arthritis
• poor posture or bone alignment caused by developmental abnormalities
• metabolic disorders

Diagnosis

The two most important diagnostic clues in the patient's history are the pattern of joint involvement and the presence or absence of fever, rash, or other symptoms outside the joints.

History and physical examination

When taking vital signs (i.e., blood pressure, weight, temperature), the patient's gait and arm and hand movement should be observed by the nursing staff or physician assistants; if pain is the chief complaint, the affected joint should be examined. After a brief examination, the nurse, nurse practitioner, or physician assistant should ask the length of time the pain has affected the patient and if there have been any limitations in his or her work or home life. The practitioner should record abnormal symptoms on the intake sheet for review by the physician. As part of the physical examination, the physician will evaluate swelling, limitations on the range of motion, pain on movement, and crepitus (i.e., cracking or grinding sound heard during joint movement). Osteoarthritis is often similar in presentation to rheumatoid arthritis, but lacks the presence of inflammation (until its very late stages) found in rheumatoid arthritis.