Monoarthritis, not elsewhere classified, unspecified knee

This code signifies inflammation of a single, unspecified knee joint, where the underlying cause is not specified or classifiable elsewhere. It represents a localized arthritic condition affecting only one knee, without further diagnostic specificity regarding its etiology.

Apply this code when documentation clearly indicates monoarthritis of a knee, but the specific type (e.g., infectious, crystal-induced, post-traumatic) is not identified. This is appropriate when the physician's assessment points to a single inflamed knee joint without a definitive diagnosis beyond "monoarthritis."

• Avoid using this code if a more specific diagnosis for the monoarthritis is available (e.g., gouty arthritis, septic arthritis).
• Ensure the documentation specifies "knee" and "monoarthritis" without further etiological detail.
• Consider querying the provider for a more specific diagnosis if the clinical picture suggests a particular type of monoarthritis.