YY/T 0809.10-2022Implants for surgery-Partial and total hip-joint prostheses - Part 10: Determination of resistance to static load of modular femoral heads (English PDF)

Foreword

This document was drafted in accordance with the rules provided in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.

This document is Part 10 of YY/T 0809 Implants for surgery - Partial and total hip- joint prostheses. The following parts have been issued for YY/T 0809:

-- Part 1: Classification and designation of dimensions;

-- Part 2: Articulating surfaces made of metallic, ceramic and plastics materials;

-- Part 4: Determination of endurance properties and performance of stemmed femoral components;

-- Part 6: Endurance properties testing and performance requirements of neck region of stemmed femoral components;

-- Part 8: Endurance performance of stemmed femoral components with application of torsion;

-- Part 10: Determination of resistance to static load of modular femoral heads;

-- Part 12: Deformation test method for acetabular shells;

-- Part 13: Determination of resistance to torque of head fixation of stemmed femoral components.

This document replaces YY/T 0809.10-2014, Implants for surgery - Partial and total hip joint prostheses - Part 10: Determination of resistance to static load of modular femoral heads. Compared with YY/T 0809.10-2014, in addition to editorial changes, the main technical changes are as follows:

-- Add terms and definitions: bore (3.1), basic design control (3.5), 3D control elements (3.6), head/neck conical taper connection (3.10).

-- Modify the hardness requirement of the conical bore assemblies from 150 HBW ~ 200 HBW to a hardness of at least 150 HBW (see 5.1.3; 5.1.3 of the 2014 edition).

-- In YY/T 0809.10-2014, the copper ring load distributing device is optional. In this Part, the copper ring load distributing device must be used for the static compression test (see 7.3.1; 6.2.1 of the 2014 edition).

-- Add the requirement for preload, which shall be 0.1% of the maximum force of the testing machine or between 50 N and 200 N (see 7.3.2).

-- Modify the requirements for pullout speed (see 7.4.2; 6.3.2 of the 2014 edition).

-- Modify part of the content in Figure 2 and Figure 3 (see Figure 2 and Figure 3;

Figure 2 and Figure 3 of the 2014 edition).

-- Delete "Methods for cleaning test specimens" (see Appendix A of the 2014 edition).

-- Delete "If it is not applicable" [see 6.1.2b) and 6.2.2 of the 2014 edition] and "If the stroke rate is set for the testing machine, the reason and the value of the stroke rate shall be explained" [see 7d) of the 2014 edition], the loading mode is no longer preferred to the load control mode.

This document uses the redraft method to revise and adopt ISO 7206-10:2018 Implants for surgery - Partial and total hip-joint prostheses - Part 10: Determination of resistance to static load of modular femoral heads. Compared with ISO 7206-10:2018, the main technical differences are as follows:

-- Adjust the normative references with technical differences to adapt to the technical conditions of China. The adjustments are concentrated in Clause 2 "Normative references". The specific adjustments are as follows:

- Use GB/T 231.1 which modifies and adopts the international standard to replace

ISO 6506-1;

- Use GB/T 10610 which is equivalent to the international standard to replace

ISO 4288;

- Use GB/T 16825.1 which is equivalent to the international standard to replace

ISO 7500-1;

- Use YY/T 0809.1 which is equivalent to the international standard to replace ISO 7206-1.

-- Change "as shown in Figure 1a)" to "as shown in Figure 1b)" in c) of the "Test report", as it is an editorial error in ISO 7206-10:2018.

1 Scope

This document specifies methods of determining the compressive (fracture) or the tension (disassembly) loads required, under specific laboratory conditions, to cause failure of a modular head system.

This document applies to components made of metallic and non-metallic materials, such as femoral heads of partial or total hip-joint replacements of modular construction (i.e., a head/neck conical taper connection).

This document excludes methods of examining and reporting the test specimens.

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 version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

GB/T 231.1, Metallic materials - Brinell hardness test - Part 1: Test method (GB/T 231.1-2018, ISO 6506-1:2014, MOD)

GB/T 10610, Geometrical product specifications (GPS) - Surface texture: Profile method - Rules and procedures for the assessment of surface texture (GB/T 10610- 2009, ISO 4288:1996, IDT)

GB/T 16825.1, Metallic materials - Calibration and verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Calibration and verification of the force-measuring system (GB/T 16825.1-2008, ISO 7500-1:2004, IDT)

YY/T 0809.1, Implants for surgery - Partial and total hip joint prostheses - Part 1: Classification and designation of dimensions (YY/T 0809.1-2010, ISO 7206-1:2008, IDT)

It is capable of sustaining expected forces and constructed so that the line of force application passes through the center of the femoral head and is aligned with the neck axis as indicated in Figure 5. The design of the fixture used to pull against the head requires either an opening on one side or a modular design. This fixture shall be sufficiently rigid to prevent deformation which might apply a bending moment or torque to the neck.

6 Test specimens

6.1 Manufacture of the cones and bores used in femoral head modularity requires precision control in order that the cone and bore mate and lock consistently. Basic design controls include engagement length between the bore and the cone; bore surface roughness; cone surface roughness; and the three-dimensional (3D) control elements.

The 3D control elements include bore and cone circularity, bore and cone straightness, cone angle, bore angle, bore and cone concentricity, and bore and cone diameter at a reference point. Different manufacturers have different ways of controlling and measuring the basic design controls and 3D control elements they use in the manufacture of modular head systems. For this test, it is required that these parameters are always within the manufacturer's requirements. If the implant manufacturers are running the tests, all basic design controls and 3D control elements and tolerances should be reported for the specimens.

6.2 The alignment of the femoral cone and bore axis with the line of force application is important. If the applied force is not in line with the axis of the cone and the bore, it can affect the results of the test. It is more difficult to align the cone section of an actual femoral implant to the line of force application and maintain that alignment under large forces. It is acceptable to produce a simulated cone that has a flat base that makes that alignment easier. Those simulated cones shall be fabricated from the same material in the same metallurgical condition and be produced using the same fabrication methods as the actual femoral implant. They shall have all the same basic design controls and 3D control elements as actual implants. All basic design controls and 3D control elements used in the manufacture of test specimens shall be measured and recorded using the same techniques used in the production of actual implants.

6.3 All heads used in the tests shall be actual implants. The manufacturer shall ensure that the heads tested have all the same basic design controls and 3D control elements as actual implants. If tested under the control of the manufacturer, the basic design controls and 3D control elements for each test head shall be measured and recorded.