M06.0 - Rheumatoid arthritis without rheumatoid factor
M06.06 - Rheumatoid arthritis without rheumatoid factor, knee
M06.061 - Rheumatoid arthritis without rheumatoid factor, right knee
M06.062 - Rheumatoid arthritis without rheumatoid factor, left knee
M06.069 - Rheumatoid arthritis without rheumatoid factor, unspecified knee