Other reactive arthropathies, unspecified knee

This code signifies an inflammatory joint condition affecting the knee, not caused by direct infection of the joint itself, but rather as a reaction to an infection elsewhere in the body. It encompasses various forms of reactive arthritis where the specific type is not further identified.

Apply this code when documentation indicates reactive arthropathy of an unspecified knee, and the underlying cause or specific type of reactive arthritis (e.g., Reiter's syndrome, post-dysenteric) is not specified. This code is appropriate when the knee is the primary site of symptoms for the reactive process.

• Ensure documentation specifies "unspecified knee" if only one knee is affected and laterality is not noted, or if both knees are affected but laterality is not differentiated.
• Avoid using this code if a more specific type of reactive arthropathy (e.g., Reiter's disease) or a specific infectious agent causing the reactive arthritis is documented.
• Always look for an underlying infectious process that may be coded separately as the primary diagnosis, with this code serving as a secondary diagnosis.