Oth rheumatoid arthritis with rheumatoid factor of left knee

This diagnosis code signifies a form of rheumatoid arthritis, an autoimmune disease causing chronic inflammation, specifically affecting the left knee. The "other" classification indicates that the presentation does not fit into the more specific categories of rheumatoid arthritis, and the presence of rheumatoid factor (RF) in the patient's blood is confirmed.

Apply this code when a patient presents with documented rheumatoid arthritis primarily affecting the left knee, and serological testing confirms the presence of rheumatoid factor. This is appropriate for cases where the specific type of rheumatoid arthritis (e.g., without organ involvement, with polyarticular involvement) is not further specified beyond the RF positivity and knee involvement. Documentation should clearly state "rheumatoid arthritis," "left knee involvement," and "rheumatoid factor positive."

• Ensure documentation specifies "left knee" and not just "knee" or "bilateral knees."
• Confirm the presence of rheumatoid factor (RF) in the patient's medical record.
• Do not use this code if the rheumatoid arthritis is specified as juvenile, with organ involvement, or other more specific types; select the appropriate subcategory.