Rheumatoid myopathy with rheumatoid arthritis of left elbow

This code signifies a muscle disease (myopathy) directly caused by rheumatoid arthritis, specifically affecting the left elbow. It indicates that the inflammatory process of rheumatoid arthritis has led to muscle weakness, pain, or dysfunction in the musculature surrounding the left elbow joint.

Apply this code when documentation clearly states a diagnosis of rheumatoid myopathy in a patient with rheumatoid arthritis, with the manifestation localized to the left elbow. Supporting documentation would include physician notes detailing muscle involvement (e.g., weakness, atrophy, pain) attributed to RA in the left elbow region, often alongside imaging or electromyography findings.

• Ensure the documentation explicitly links the myopathy to rheumatoid arthritis and specifies the left elbow.
• Do not use this code for general muscle pain or weakness in a patient with RA unless myopathy is diagnosed.
• Always sequence the underlying rheumatoid arthritis code (e.g., M05.xx) before this code, if applicable and not already inherent in the M05.422 code itself.