ISO 19233-1:2017

INTERNATIONAL ISO
STANDARD 19233-1
First edition
2017-05
Implants for surgery — Orthopaedic
joint prosthesis —
Part 1:
Procedure for producing parametric
3D bone models from CT data of the
knee
Implants chirugicaux — Prothèses articulaires orthopédiques —
Partie 1: Mode opératoire de production de modèles paramétriques
d’os en 3D à partir de données de CT du genou
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
4 Principles . 2
5 Requirements . 2
5.1 Imaging conditions . 2
5.1.1 Medical imaging apparatus . 2
5.1.2 Region of interest . 2
5.1.3 Body position . 3
5.1.4 Field of view (FOV) . 3
5.1.5 Slice thickness and slice spacing . 3
5.1.6 Reconstruction kernel . 4
5.1.7 X-ray tube current . 4
5.1.8 X-ray tube voltage . 4
5.1.9 Precautions . 4
5.1.10 Leg alignment . 4
5.2 Software regulatory requirements . 5
5.3 Generation of bone models . 5
5.3.1 Segmentation methods for bone and cartilage region . 5
5.3.2 3D reconstruction . 6
5.3.3 Data format . 6
Annex A (informative) Method of the software validation . 7
Annex B (informative) CT scanning conditions . 8
Bibliography . 9
Foreword
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electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
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URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee
SC 4, Bone and joint replacements.
A list of all parts in the ISO 19233 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

Introduction
In accordance with its widespread use of medical X-ray computed tomography apparatus, three-
dimensional (3D) bone models reconstructed from digital tomographic images have been widely used
for various applications such as preoperative planning, surgical navigation, robotic surgeries, patient
matched instruments and personalized total knee joint prosthesis. However, the conditions of taking
tomographic images are different among hospitals and not internationally unified. To measure bones
accurately, precise 3D bone models reconstructed from tomographic images should be used. On the
other hand, since conditions of this reconstruction process are left up to operators’ and/or medical
institutions’ discretion, this document provides a standard way of reconstructing 3D bone models.
INTERNATIONAL STANDARD ISO 19233-1:2017(E)
Implants for surgery — Orthopaedic joint prosthesis —
Part 1:
Procedure for producing parametric 3D bone models from
CT data of the knee
1 Scope
This document provides requirements for capturing necessary bone geometries, when using a medical
X-ray computed tomography apparatus, to provide the information for applications such as preoperative
planning, surgical navigation, robotic surgeries, patient matched instruments and personalized total
knee joint prosthesis. The conditions to scan images of bones and the conditions to reconstruct three-
dimensional bone models are provided.
NOTE Requirements for the competence of testing laboratories appropriate to help to ensure the reliability
and accuracy of the computational measurements can be found in ISO/IEC 17025.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 7207-1, Implants for surgery — Components for partial and total knee joint prostheses — Part 1:
Classification, definitions and designation of dimensions
ISO 14971, Medical devices — Application of risk management to medical devices
ISO 21536, Non-active surgical implants — Joint replacement implants — Specific requirements for knee-
joint replacement implants
IEC 61223-2-6, Evaluation and routine testing in medical imaging departments — Part 26: Constancy
tests — Imaging performance of computed tomography X-ray equipment
IEC/TR 60788, Medical electrical equipment — Glossary of defined terms
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC/TR 60788, IEC 61223-2-6,
ISO 21536, ISO 7207-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1.1
3D bone model
bone model that is reconstructed based on CT images and made from 3D shape data in the computer
3.1.2
personalized artificial knee joint
knee joint prosthesis specifically designed for each patient
3.1.3
field of view
scanning field of view which includes the intended side of the lower limb
3.1.4
CT apparatus
X-ray computed tomography
technology that uses computer-processed x-rays to produce tomographic images (virtual “slices”) of
specific areas of the scanned object, allowing the user to see what is inside it without cutting it open
Note 1 to entry: Digital geometry processing is used to generate a three-dimensional (3D) image of an object
from two-dimensional (2D) radiographic images taken by the CT apparatus in a spiral path around a s
...