ICD-10 codes

How an ICD-10 code is built

A code consists of a letter and digits. The letter is the chapter: M — diseases of the musculoskeletal system, S — injuries, G — diseases of the nervous system. The two digits after the letter are the category (for example M17 — knee osteoarthritis), and the digit after the point specifies the variant (M17.1 — other primary knee osteoarthritis).

Many countries use national versions with extra characters. Germany uses ICD-10-GM: a fifth digit gives the location, the letters G, V, Z or A give the certainty of the diagnosis (confirmed, suspected, condition after, excluded), and R, L or B give the side (right, left, both).

The World Health Organization adopted ICD-11 in 2022, but reports and invoices in most countries, including Germany, still use ICD-10. The tables below give ICD-10 codes at category and subcategory level.

Knee: ICD-10 codes

Shoulder: ICD-10 codes

Foot and ankle: ICD-10 codes

What to know about codes

• The doctor chooses the code. The same diagnosis can be coded differently by different doctors — for example low back pain as M54.5, or M51.2 if a disc protrusion is the cause.
• M19.0 is used for osteoarthritis of the shoulder, ankle and other joints; national versions add a digit for the specific joint.
• A code in a report does not mean that the diagnosis is final: in German documents the letter V only means “suspected”.
• A code does not tell you whether surgery is needed. A doctor decides this from your images and an examination — send your report for a second opinion.

What to prepare for a free review

• Images: MRI, ultrasound or X-ray (DICOM files or photos of the screen) and their reports.
• When and how the pain started, where exactly it hurts, what makes it worse or better.
• Treatment so far: injections, physiotherapy, surgery — and how it helped.
• Other conditions and medications, especially blood thinners.

With this information, a partner-clinic physician can say whether further tests are needed and which treatment options suit you.