monoarticular

Monoarticular is an adjective used in anatomy and medicine to describe something that involves or affects a single joint. The term derives from Greek monos, meaning “one,” and arthron, meaning “joint,” with the medical suffix -ic. In clinical practice, monoarticular is used to characterize conditions that involve only one joint, as opposed to oligoarticular (two to four joints) and polyarticular (five or more joints).

In rheumatology and orthopedics, distinguishing monoarticular from multiarticular disease helps guide diagnosis and management. Monoarticular arthritis specifically affects a single joint, though the underlying cause can range from injury to infection or crystal deposition. Common examples include septic arthritis, gout or other crystal arthropathies presenting with a single joint attack, trauma, or localized osteoarthritis.

In anatomy, monoarticular also describes muscles that cross a single joint, in contrast to biarticular muscles that cross two joints. For example, the vastus lateralis is a monoarticular muscle crossing only the knee, whereas the gastrocnemius is biarticular, acting across both the knee and ankle joints.

Overall, the term conveys the scope of involvement—whether a disease or structure affects one joint or crosses more than one—and is a useful classification in clinical assessment and anatomical description.