BS ISO 14242-2:2016 pdf download.Implants for surgery — Wear of total hip-joint prostheses — Part 2: Methods of measurement
1 Scope
This part of ISO 14242 specifies methods of assessment of wear of the acetabular component of total hip-joint prostheses using gravimetric techniques and changes in dimensional form of components tested in accordance with ISO 14242-1 or ISO 14242-3 as appropriate.
NOTE Some investigators have experienced problems with organic deposits affecting the results of measurements, especially with hard/hard combinations. No specific precautions are included in this part of
ISO 14242, but cleaning techniques adopted is intended to be suitable for the soils produced.
2 Normative reference
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 14242-1, Implants for surgery — Wear of total hip-joint prostheses — Part 1: Loading and displacement parameters for wear-testing machines and corresponding environmental conditions for test
ISO 14242-3, Implants for surgery — Wear of total hip-joint prostheses — Part 3: Loading and displacement parameters for orbital bearing type wear testing machines and corresponding environmental conditions for test
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 wear
material loss from components of the prosthetic joint due to combined movement and loading
4 Gravimetric method
4.1 Principle
The test specimen is soaked in a lubricant. It is repeatedly removed from the lubricant, cleaned, dried and weighed until a steady rate of fluid sorption is established. The test specimen is assessed subsequently for wear by testing for loss in mass in a knee-hip simulator. A loaded, non-articulating control specimen is intended to allow for fluid sorption and undergoes the same procedure for reference purposes.
4.2 Reagents and materials
4.2.1 Fluid test medium, in accordance with ISO 14242-1 or ISO 14242-3 as appropriate.
4.2.2 Control specimen, in accordance with ISO 14242-1 or ISO 14242-3 as appropriate.
4.2.3 Propan-2-ol.
4.3 Apparatus
4.3.1 Balance, with an accuracy of ±0,1 mg, of sufficient capacity for the mass of the test specimen.
4.3.2 Ultrasonic cleaner.
4.3.3 Vacuum drying system, capable of achieving a vacuum of at least 13,33 Pa.
4.3.4 Filtered inert-gas jet, e.g. nitrogen.
4.4 Preparation of test specimen for gravimetric measurements
4.4.1 Soak the test specimen and control specimen in the fluid test medium (4.2.1) for 48 h ± 4 h.
4.4.2 Remove the test specimen and control specimen from the fluid test medium (4.2.1) and clean in the ultrasonic cleaner (4.3.2).
A typical cleaning regime in the ultrasonic cleaner is as follows:
a) vibrate for 10 min in deionized water;
b) rinse in deionized water;
c) vibrate for 10 min in a mixture of ultrasonic cleaning detergent in deionized water at the concentration recommended by the detergent manufacturer;
d) rinse in deionized water;
e) vibrate for 10 min in deionized water;
f) rinse in deionized water;
g) vibrate for 3 min in deionized water;
h) rinse in deionized water;
i) dry in a vacuum drying chamber (4.3.3).
Care should be taken to avoid abrasion in the ultrasonic cleaner which could lead to change in mass.
BS ISO 14242-2:2016 pdf download
