Myositis ossificans progressiva, left thigh

This code signifies a rare, progressive genetic disorder characterized by the formation of bone in muscles, tendons, ligaments, and other connective tissues, specifically affecting the left thigh. This heterotopic ossification leads to significant pain, swelling, and progressive loss of joint mobility.

Apply this code when documentation explicitly states a diagnosis of myositis ossificans progressiva (also known as fibrodysplasia ossificans progressiva) and specifies the left thigh as the affected anatomical site. This diagnosis is typically confirmed through clinical examination, imaging studies (X-rays, CT scans), and genetic testing.

• Ensure the documentation clearly distinguishes between myositis ossificans progressiva (a genetic disorder) and myositis ossificans traumatica (a localized, non-progressive condition).
• Verify the specific anatomical site (e.g., left thigh) is documented to ensure accurate laterality coding.
• Consider additional codes for associated symptoms or complications, such as pain (e.g., M79.652 for pain in left thigh), if documented.