Diagnostic imaging of osteoarthritis.

Osteoarthritis is a common orthopedic problem in the small animal patient. In most cases, the degenerative changes in the joint are secondary to some predisposing cause. The objective of diagnostic imaging is to define the extent and nature of the degenerative changes and to identify the responsible underlying abnormality. To achieve this, appropriate imaging procedures should be used. Although conventional radiography is the most common method used to evaluate osteoarthritis, there has been an increase in the application of other imaging technologies during the past several years. These modalities can provide the clinician with additional information that can improve case management. The radiographic changes that accompany osteoarthritis are reviewed, and indications for the various imaging modalities are outlined. The causes and presentation of osteoarthritis of the major diarthrodial joints of the appendicular skeleton are described.