Investigation of polyarthritis (summary)

This is a basic article for medical students and other non-radiologists

Polyarthritis (arthritis affecting several joints) is common, especially in older patients. Symptoms may range from mild pain and restriction to severe, debilitating disease with mutilated joints.

Assessment

Arthritis may be broadly split into degenerative and inflammatory types. The distinction between the two is often possible by taking a detailed history and examining the joints. 

Investigations

Further investigation of polyarthritis aims to confirm the diagnosis and assess severity. In both degenerative and inflammatory disease, x-rays are helpful to assess the involvement of the joint surfaces and the condition of the adjacent bones.

Radiological assessment in chronic joint disease and specifically in polyarthritis often employs x-rays of both sides to allow for comparison. 

Degenerative polyarthritis

Degenerative polyarthritis (osteoarthritis) most commonly affects the weight-bearing joints and are commonly seen on pelvic x-rays and AP x-rays of the knees. Common findings include joint space reduction, joint surface sclerosis and irregularity.

Inflammatory polyarthritis

Inflammatory polyarthritis is a broad group of diseases that includes rheumatoid arthritis. Is much less common in the weight-bearing joints and is much more commonly seen in the hands and feet. Inflammatory arthritis also results in joint space reduction but may cause erosions around the joint which is a feature of disease that will trigger escalation of treatment.

Common pathology

• osteoarthritis
• rheumatoid arthritis
• psoriatic arthropathy