ICS 11.040.40                          MHD 02

Reaffirmed 2022

NATIONAL FOREWORD

This Indian Standard (Part 4 ) (First Revision) which is identical with ISO 7206-4 : 2010 ‘Implants for surgery — Partial and total hip joint prostheses — Part 4: Determination of endurance properties and performance of stemmed femoral components’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Orthopaedic Instruments Implant and Accessories Sectional Committee and approval of the Medical Equipment and Hospital Planning Division Council.

IS 12375 (Part 4) was first published in 1993 by adopting ISO 7206-4 : 1989. This first revision has been taken up to align with the latest ISO 7206-4 brought out in 2010.

This part of standard covers some aspects which were not sufficiently described in earlier edition and some parts of the test method did not reflect the current test practices as shown below:

a) Test conditions for anteverted stems will result in a significant decrease of the medial-lateral bending forces. This reflects the “best case” test condition in comparison to “worst case” conditions for non-anteverted stems and will lead to test results not reflecting the high forces in the human body, because the rotated position is not considered.

b) Specific test conditions for stemmed femoral components with CT distance = 120 mm are not considered.

NOTE - The dimension CT is the distance between the centre of the femoral head, C, and the most distal point of the stem, T.

c) Changes in the potting level in comparison to earlier edition without changes in the corresponding performance standard.

In order to overcome these disadvantages this edition define the test conditions for three types of stem length, to describe the test procedure and stem axis definition particularly for anteverted stems more precisely and to harmonize the test conditions with the endurance performance.

This standard in some respects allows more accurate and easier handling by the test laboratories and defines a clear separation of stemmed femoral components into three categories:

a) stems with CT distance = 120 mm;

b) stems with CT distance 120 mm < CT = 250 mm; and

c) stems with CT distance > 250 mm.

It includes performance criteria for these components. This will lead to a higher acceptance of the test method and more reproducible test results.

The text of the ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions are however not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker while in Indian Standards, the current practice is to use a point (.) as the decimal marker.