YY/T 0811-2021 English PDF (YYT0811-2021)

This Standard specifies relevant requirements and test methods for irradiation-crosslinked (extensively crosslinked) ultra-high molecular weight polyethylene fabricated (UHMWPE) forms for surgical implant applications. This Standard is applicable to pure resin powder required by GB/T 19701.1 or extensively irradiation-crosslinked UHMWPE products produced by molding compounds required by GB/T 19701.2. This Standard is only applicable to UHMWPE products that have been extensively irradiated by ¦Ã rays and electron beam ionizing radiation sources. This Standard does not apply to UHMWPE that has only been treated with gas plasma, ethylene oxide or ionizing radiation with a dose of less than 40kGy, that is, materials that have undergone routine sterilization only. NOTE 1: The exact relationship between the mechanical properties of the above articles and the in vivo performance has not been established. Although scientists are devoted to the study of the relationship between polymer structure, polymer properties and polymer design, the above relationship has not been satisfactorily explained.

YY/T 0811-2021
YY
PHARMACEUTICAL INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 11.040.40
C 35
Replacing YY/T 0811-2010
Extensively irradiation-crosslinked ultra-high molecular
weight polyethylene fabricated forms for surgical implant
applications
ISSUED ON: SEPTEMBER 06, 2021
IMPLEMENTED ON: SEPTEMBER 01, 2022
Issued by: National Medical Products Administration
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 6
4 Sampling ... 6
5 Relevant requirements for extensively crosslinked UHMWPE products ... 6 6 Biocompatibility ... 8
Annex A (informative) Basic principle ... 9
Bibliography ... 11
Extensively irradiation-crosslinked ultra-high molecular
weight polyethylene fabricated forms for surgical implant
applications
1 Scope
This Standard specifies relevant requirements and test methods for irradiation- crosslinked (extensively crosslinked) ultra-high molecular weight polyethylene fabricated (UHMWPE) forms for surgical implant applications.
This Standard is applicable to pure resin powder required by GB/T 19701.1 or extensively irradiation-crosslinked UHMWPE products produced by molding compounds required by GB/T 19701.2. This Standard is only applicable to UHMWPE products that have been extensively irradiated by γ rays and electron beam ionizing radiation sources.
This Standard does not apply to UHMWPE that has only been treated with gas plasma, ethylene oxide or ionizing radiation with a dose of less than 40kGy, that is, materials that have undergone routine sterilization only.
NOTE 1: The exact relationship between the mechanical properties of the above articles and the in vivo performance has not been established. Although scientists are devoted to the study of the relationship between polymer structure, polymer properties and polymer design, the above relationship has not been satisfactorily explained. The following mechanical tests are commonly used to assess the repeatability of manufacturing procedures and are suitable for comparative studies of different materials.
NOTE 2: The following warning text applies only to the test method part of Chapter 5. This Standard does not attempt to describe all the safety issues involved, even those related to its use. It is the responsibility of the user of this Standard to establish appropriate safety and operating practices, and to clarify the applicability of regulatory limitations prior to application. 2 Normative references
The following referenced documents are indispensable for the application 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. GB/T 16886.1, Biological evaluation of medical devices -- Part 1: Evaluation and testing within a risk management process
GB/T 16886.2, Biological evaluation of medical devices -- Part 2: Animal welfare requirements
GB/T 16886.3, Biological evaluation of medical devices -- Part 3: Tests for genotoxicity, carcinogenicity and reproductive toxicity
GB/T 16886.4, Biological evaluation of medical devices -- Part 4: Selection of tests for interactions with blood
GB/T 16886.5, Biological evaluation of medical devices -- Part 5: Tests for in vitro cytotoxicity
GB/T 16886.6, Biological evaluation of medical devices -- Part 6: Tests for local effects after implantation
GB/T 16886.7, Biological evaluation of medical devices -- Part 7: Ethylene oxide sterilization residuals
GB/T 16886.9, Biological evaluation of medical devices -- Part 9: Framework for identification and quantification of potential degradation products
GB/T 16886.10, Biological evaluation of medical devices -- Part 10: Tests for irritation and skin sensitization
GB/T 16886.11, Biological evaluation of medical devices -- Part 11: Tests for systemic toxicity
GB/T 16886.12, Biological evaluation of medical devices -- Part 12: Sample preparation and reference materials
GB/T 19701.1, Implants for surgery -- Ultra-high-molecular-weight polyethylene -- Part 1: Powder form
GB/T 19701.2, Implants for surgery -- Ultra-high-molecular-weight polyethylene -- Part 2: Moulded forms
GB/T 21461.2, Plastics -- Ultra-high-molecular-weight polyethylene (PE-UHMW) moulding and extrusion materials -- Part 2: Preparation of test specimens and determination of properties
YY/T 0772.4, Surgical implants - Ultra high molecular weight polyethylene - Part 4: Test method for oxidation index
YY/T 0814, Standard test method for evaluating trans-vinylene yield in irradiated ultra-high-molecular-weight polyethylene fabricated forms intended for surgical implants by infrared spectroscopy
YY/T 0815, Standard test method for measurement of enthalpy of fusion, percent crystallinity, and melting point of ultra-high-molecular weight polyethylene by means of differential scanning calorimetry
YY/T 1430, Standard test method for small punch testing of ultra-high molecular weight polyethylene used in surgical implants
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. 3.1 UHMWPE fabricated form
UHMWPE of any shape made of pure polymer powder for surgical implants before crosslinking, packaging and sterilization.
3.2 extensively crosslinked UHMWPE
Crosslinked UHMWPE material that is formed by receiving γ and/or electron beam ionizing radiation with a total dose exceeding 40kGy.
3.3 ionizing radiation
γ rays or high-energy electron radiation.
3.4 crosslinking
The process of generating chemical bonds between UHMWPE molecular chains by ionizing radiation.
4 Sampling
If applicable, each batch of powder and products shall be determined according to the requirements of this Standard. The sampling size and steps can be in accordance with the provisions of GB/T 21461.2 or the agreement between the buyer and the seller. 5 Relevant requirements for extensively crosslinked
UHMWPE products
5.1 Requirements for synthetics
The powder and molding compound for manufacturing extensively crosslinked UHMWPE materials shall meet the requirements of GB/T 19701.1 and GB/T 19701.2. 5.2 Physical requirements
Annex A
(informative)
Basic principle
A.1 This standard aims to provide the minimum necessary test methods for determining the physical, chemical and mechanical properties of radiation extensively crosslinked UHMWPE materials for orthopedic or spinal implants.
A.2 One of the purposes of this Standard is to provide guidance to regulatory authorities and surgical implant manufacturers through a set of standard test methods for determining the characteristics of extensively crosslinked UHMWPE materials. A.3 Even though it is now possible to identify test methods for characterizing extensively crosslinked UHMWPE, it is still not possible to specify acceptable minimum values for each test method. Because in most of the above-mentioned test methods, the correlation between the measured properties of the material and the clinical performance is currently unknown. Therefore, material manufacturers are required to formulate minimum standards for the production process of their extensively crosslinked UHMWPE materials. At the same time, use the test methods provided by this Standard to verify the production process.
A.4 Although the minimum test methods necessary for the verification of the production process of extensively crosslinked UHMWPE materials are listed in Table 1, they are not necessarily implemented as routine tests in quality control. Manufacturers need to be responsible for developing technical specifications for their materials, and decide which of the test methods listed in Table 1 will be routinely tested and implemented in the quality control program.
A.5 Fatigue resistance is an attribute we want extensively crosslinked UHMWPE to have. Table 2 lists the fatigue crack growth test methods used to test this property. The fatigue crack growth test described in ASTM E 647 is based on the principles of linear elastic fracture mechanics (e.g., assumed under plane strain conditions), but it is not strictly applicable to ductile polymers (such as UHMWPE, whether extensively crosslinked or not). Therefore, the interpretation of the current UHMWPE fatigue crack growth test data is still limited, because the test results are only applicable to samples with specific geometries. Furthermore, there is still debate in the theoretical community as to which of the extensively crosslinked UHMWPE properties, such as the Paris regime index and/or the initial value of ΔK, is most effective for determining in fatigue crack growth tests. If a more effective UHMWPE fatigue performance test is determined in the future, it may also be included in Table 1.
A.6 Free radical analysis is also considered an important test for extensively crosslinked