M05.8 - Other rheumatoid arthritis with rheumatoid factor
M05.86 - Other rheumatoid arthritis with rheumatoid factor of knee
M05.861 - Other rheumatoid arthritis with rheumatoid factor of right knee
M05.862 - Other rheumatoid arthritis with rheumatoid factor of left knee
M05.869 - Other rheumatoid arthritis with rheumatoid factor of unspecified knee