ISO 8549-4:2026

• Abstract:

  This document defined terms for the description of surgical limb amputations and amputation procedures. NOTE Traumatic limb loss and congenital limb deficiency are not included in this document.

• Status: Published
• Publication Date: 19-May-2026
• ICS: 01.040.11 - Health care technology (Vocabularies)
• ICS: 11.040.40 - Implants for surgery, prosthetics and orthotics
• Technical Committee: ISO/TC 168 - Prosthetics and orthotics
• Drafting Committee: ISO/TC 168 - Prosthetics and orthotics
• Current Stage: 6060 - International Standard published
• Start Date: 20-May-2026
• Due Date: 02-May-2026
• Completion Date: 20-May-2026

• Revises: ISO 8549-4:2020 - Prosthetics and orthotics — Vocabulary — Part 4: Terms relating to limb amputation
• Effective Date: 06-May-2023

ISO 8549-4:2026 is an International Standard from ISO that gives vocabulary for limb amputation in prosthetics and orthotics. It defines terms for surgical limb amputations and amputation procedures so clinicians, researchers, manufacturers, and other users can describe cases in the same way.

What does ISO 8549-4:2026 specify?

ISO 8549-4:2026 specifies terms for the description of surgical limb amputations and amputation procedures. Traumatic limb loss and congenital limb deficiency are outside its scope.

The document is organized as:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Index

Clause 3 is divided into four topics: general limb amputation, upper limb amputation levels, lower limb amputation levels, and amputation procedures. That structure matters in practice because the terminology is grouped by the body region and by the kind of event being described.

What are the key requirements of ISO 8549-4:2026?

ISO 8549-4:2026 is a terminology standard, so its main substance is the defined wording used to describe amputations. The important point for users is to record the limb, side, level, and procedure accurately, because the document repeatedly shows that a complete description depends on those details.

General limb amputation terms

Clause 3.1 defines the core terms for any limb amputation, including limb amputation, upper limb amputation, lower limb amputation, residual limb / residuum / stump, and level of amputation. In practice, these are the terms that support clinical notes, case reports, registries, and communication between teams.

Clause 3.1 also covers combinations such as unilateral upper and lower limb amputation, contralateral upper and lower limb amputation, bilateral upper limb amputation, bilateral lower limb amputation, triple amputation, and quadruple amputation. These terms matter when a record has to show how many limbs are involved and on which side.

Upper limb amputation levels

Clause 3.2 sets out the named upper-limb levels from partial hand amputation through wrist disarticulation, transradial amputation, elbow disarticulation, transhumeral amputation, shoulder disarticulation, and scapulothoracic disarticulation, also called forequarter amputation. This helps users describe the exact anatomical level rather than relying on vague wording.

For partial hand amputation, the document breaks the term down further into thumb amputation, phalangeal amputation, metacarpophalangeal disarticulation, metacarpal amputation, carpometacarpal disarticulation, and carpal amputation. The note to entry says a complete description requires the amputated bones and their levels, which is important for precise surgical and prosthetic documentation.

Lower limb amputation levels

Clause 3.3 does the same for the lower limb, from partial foot amputation through ankle disarticulation, transtibial amputation, knee disarticulation, transfemoral amputation, hip disarticulation, and transpelvic amputation. This gives a shared vocabulary for records, outcome studies, and prosthetic planning.

Partial foot amputation is also broken down into phalangeal, metatarsophalangeal disarticulation, metatarsal, tarsometatarsal disarticulation, and tarsal amputation. As with partial hand amputation, the document says the amputated bones and their levels must be identified for a full description.

Amputation procedures

Clause 3.4 defines procedural terms: initial amputation, initial upper limb amputation, initial lower limb amputation, revision amputation, two-stage amputation, and reamputation. These terms help distinguish a first operation from later surgery on the same limb.

The notes to entry are clinically useful. For example, the note on initial lower limb amputation says the description shall specify upper or lower limb and left or right side, while the note on two-stage amputation explains that the first stage may remove devitalized or infected parts and the second stage may involve revision, a higher level, and wound closure.

What terms does ISO 8549-4:2026 define?

ISO 8549-4:2026 defines the language used to describe amputations, and several terms are especially central:

• limb amputation - surgical removal of the whole or part of a limb.
• residual limb / residuum / stump - the portion of the limb remaining after an amputation.
• level of amputation - the joint or limb segment where the amputation is performed.
• partial hand amputation - amputation of the upper limb distal to the wrist joint.
• partial foot amputation - amputation of the lower limb distal to the ankle joint.
• revision amputation - surgery on a previously amputated limb without changing the amputation level.
• reamputation - amputation of an amputated limb to a higher level.

Who uses ISO 8549-4:2026?

ISO 8549-4:2026 is intended for all practitioners who deal with persons who have had a limb amputation. In practice, that includes surgeons, prosthetics and orthotics professionals, and other clinicians who need to describe cases clearly and compare them with other cases.

The introduction also names persons who have had an amputation, epidemiologists, researchers, manufacturers, and government and non-government organisations. These users need shared terminology for patient records, studies, product development, reporting, and communication across organisations.

What changed in ISO 8549-4:2026 from the previous edition?

ISO 8549-4:2026 is the third edition and cancels and replaces ISO 8549-4:2020. The foreword says the document has been technically revised.

The stated changes are:

• hyphens in anatomical terms, such as transpelvic, have been abandoned in line with other parts of the ISO 8549 series
• the term “amputee” has been removed and replaced with “person who have had an amputation”

What does the ISO 8549-4:2026 document contain?

ISO 8549-4:2026 contains front matter, a foreword, an introduction, three clauses, and an index. Clause 3 is the main body and contains the defined terms, grouped into four subclauses.

The entries use short notes to make the terminology more precise, especially where a full description must include the limb, side, bones, or level involved. The document also points users to ISO and IEC terminology databases, which supports consistent lookup and use of the terms in standardization work.

The index lists the preferred terms and synonym forms for quick navigation, which is useful when the document is used for coding, reporting, or terminology checking.

International
Standard
ISO 8549-4
Third edition
Prosthetics and orthotics —
2026-05
Vocabulary —
Part 4:
Terms relating to limb amputation
Prothèses et orthèses — Vocabulaire —
Partie 4: Termes relatifs à l'amputation de membres
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General limb amputation .1
3.2 Upper limb amputation levels .2
3.3 Lower limb amputation levels .3
3.4 Amputation procedures .4
Index . 5

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 168, Prosthetics and orthotics.
This third edition cancels and replaces the second edition (ISO 8549-4:2020), which has been technically
revised.
The main changes are as follows:
— the use of hyphens in anatomical terms, such as transpelvic, has been abandoned in line with other parts
of the ISO 8549 series;
— the term “amputee” has been removed from the standard and replaced with “person who have had an
amputation”.
A list of all parts in the ISO 8549 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document provides an internationally accepted terminology which describes the full range of limb
amputation levels and procedures.
This is intended for the use of all practitioners dealing with persons who have had a limb amputation to
describe their clinical experiences and compare them with the experience of others.
It can also be of value to other stakeholders, including persons who have had an amputation, epidemiologists,
researchers, manufacturers, and government and non-government organisations.

v
International Standard ISO 8549-4:2026(en)
Prosthetics and orthotics — Vocabulary —
Part 4:
Terms relating to limb amputation
1 Scope
This document defined terms for the description of surgical limb amputations and amputation procedures.
NOTE Traumatic limb
...