BS ISO 7206-6:2013 pdf free download.Implants for surgery —Partial and total hip jointprostheses – Part 6: Endurance properties testing andperformance requirements of neck region of stemmed femoral components.
4Principle of the test method
The test specimen is embedded in a solid medium.For modular stems, the protruding part of the testspecimen is immersed in a fluid test medium. A cyclic load is applied to the head of the test specimenuntil one of the conditions mentioned in 8.10 occurs.
5 Materials
5.1 Embedding medium, i.e., a casting medium, which shall:a) not crack or break under the load applied during testing;b)not exhibit excessive deformation or creep;
c)be reproducible in strength and other characteristics.
The media that appear satisfactory are acrylic bone cement (see ISo 5833), filled epoxy casting resin,and liquid metal as an amorphous metal alloy.The media should have a modulus of elasticity between2 00o N/mm2 and 6 000 N/mm2.
5.2 Fluid test medium, a 9,0 g/l solution of analytical grade sodium chloride (NaCl) in distilled ordeionized water of grade 3, as specified in IS0 3696.
6Apparatus
6.1Testing machine, has the following characteristics:
a) ability to apply a cyclic load in accordance with Clause 8, at the chosen frequency;
b)tolerance in applied load is not greater than± 2 % at maximum load applied,as specified in ISO 4965;c)dynamic loading waveform is sinusoidal at the primary frequency;
d) instrumentation to monitor the values of the maximum and minimum loads and the vertical
deflection of the head of the test specimen with an uncertainty lower than ± 0,4 mm to stop themachine if deflection exceeds a prescribed value and to record the corresponding number of cyclesor the elapsed time of operation.
6.2Specimen holders, has a construction anddimensions to suit the testing machine and testspecimens.An example of a suitable holder is shown in Figure A.1.
In a few cases (circular or slightly elliptical cross-sections of stem), an additional rotationalstabilizationmay be used.This stabilization should fix only to the distal stem.
6.3 Fluid container,for tests on modular stemmed femoral components where the containersurrounding the test specimen is used to contain the test fluid together with a means of heating it.
6.4Gripping device, used to grip the test specimen by the head or neck, which retains the specimen inthe orientation specified in 8.4.An example of a suitable device is shown in Figure A.2.
6.5A means of loading the test specimen, shall be employed which maintains loading through thecentre of the head of the specimen, along the axis of the testing machine.
lt shall also incorporate a low-friction mechanism that in the horizontal plane minimizes loads notcoincident with the axis of the testing machine.BS ISO 7206-6 pdf download.