GB/T 12417.2-2025Non-active surgical implants - Osteosynthesis and joint replacement implants - Part 2: Particular requirements for joint replacement implants (English PDF)

3.1 Artificial Ligament

Implants used to strengthen or replace the body’s natural ligaments, including their necessary fixation devices.

3.2 Joint Replacement Implants

Implants used to provide similar function to natural human joints and connect with the corresponding bone, including auxiliary implant components and materials.

3.3 Mean Centre

The position inside the sphere head that has the smallest average distance from a set of points evenly distributed on the surface of the sphere.

3.4 Radial Separation Value

The maximum difference between the average radius of the sphere and the distance from a point on the sphere to the mean centre.

NOTE. The unit is micrometers (µm).

5.1 General

To achieve the intended performance, the manufacturer shall formulate design attributes in accordance with the requirements of Clause 5 of YY/T 0640-2016, and also consider the following aspects.

a) the adhesion strength and durability of surface treatments and surface coatings;

b) wear on articular surfaces and other surfaces;

c) the stability of the implant when the minimum and maximum relative movements between bones are permitted;

d) avoidance of cutting or rubbing tissue while performing functions, except in cases of implantation and removal of implants;

e) creep resistance and fracture characteristics, especially when related to ligaments.

NOTE 1.Methods for assessing wear on articular surfaces and other surfaces are described in standards such as YY/T 0651.2, YY/T 1426.1, YY/T 1426.2, and YY/T 1426.3.

NOTE 2.More specific requirements may appear in other standards, such as standards for hip replacement implants.

5.2 Surface Finishing of Metallic or Ceramic Implants Actively Connected to

Ultra-High Molecular Weight Polyethylene (UHMWPE)

For the surfaces of metallic or ceramic components that are actively connected to the UHMWPE in total joint replacements, the surface roughness (Ra) shall not exceed 0.1 µm (according to

7.2.2).

5.3 Surface Finishing of Metallic or Ceramic Implants for Partial Joint

Replacements

For the articular surfaces of metallic or ceramic components in partial joint replacements, the surface roughness (Ra) shall not exceed 0.5 µm (according to 7.2.2).

5.4 Convex Spherical Metallic or Ceramic Surfaces Actively Connected to

UHMWPE

For metallic or ceramic components that are actively connected to the UHMWPE in total joint replacements, if the articular surface is convex spherical, its surface roughness (Ra) shall not exceed 0.05 µm, and the radial separation value shall not exceed 10 µm (according to 7.2.2 and

7.2.3).

5.5 Surfaces of Spherical Metallic or Ceramic Implants for Partial Joint

Replacements

For spherical metallic or ceramic components in partial joint replacements, the articular surface roughness (Ra) shall not exceed 0.5 µm, and the radial separation value shall not exceed 100

µm (according to 7.2.2 and 7.2.3).

5.6 Surfaces of Concave Spherical UHMWPE Components

For the surfaces of concave spherical UHMWPE components in total joint replacements, the articular surface roughness (Ra) shall not exceed 2 µm, and the radial separation value shall not exceed 200 µm (according to 7.2.2 and 7.2.3).

6.1 General

The requirements of Clause 6 of YY/T 0640-2016, and the particular requirements of 6.2, apply to this document.

NOTE 1.Appendix A lists materials that have been validated and approved for use in manufacturing implants or for use with implants.

NOTE 2.Appendix B lists mating materials that have been validated, approved and unapproved for use as articular surfaces of implants.

NOTE 3.Clause 6 of YY/T 0640-2016 stipulates that materials should be selected from those that have proven suitable for clinical use in similar application scenarios. For the purposes of this document, proof of material availability must be provided, along with implantation records of at least 500 implants and at least 5 years of successful clinical use data.

6.2 Different Metals or Alloys

In certain application scenarios, where two different metals or alloys, or two identical metals or alloys in different metallographic states, are brought into contact, and non-articular surface contact is intended, the material combination used shall not produce unacceptable galvanic effects.

NOTE. Appendix C lists the approved and unapproved metallic combinations for the non-articular contact surfaces of implants.

7.1 General

Joint replacement implants shall be evaluated to demonstrate that they achieve the intended performance. The evaluation shall comply with the particular requirements of Clause 7 and 7.2 to 7.4 of YY/T 0640-2016.The evaluation shall be conducted using components that fully represent the final implantation state.

7.2 Preclinical Evaluation

7.2.1 General

Preclinical evaluation considerations include.

a) biocompatibility of previously unused materials;

b) mechanical loads and related motion conditions of the implant when it functions as described in YY/T 0640-2016;

c) fatigue testing of high-stress components meeting the requirements of YY/T 0809.4 and YY/T 0810.1;

d) wear testing of joint contact surfaces meeting the requirements of YY/T 0651.1, YY/T

0651.2, YY/T 1426.1, etc.;

e) the suitability of the implant’s dimensions and shape to the intended population;

NOTE. The suitability of the implant’s dimensions and shape to the intended population is demonstrated by the following methods. cadaver implantation; imaging systems such as

X-ray, computed axial tomography (CAT), and magnetic resonance imaging; or by referring to corresponding implants that have been clinically validated (see NOTE 3 in 6.1).

f) the adhesion strength and durability of the coating if a coating is present.

7.2.2 Surface roughness measurement

The surface roughness shall be measured according to one of the methods given in GB/T 3505.

7.2.3 Sphericity measurement

The radial separation value shall be measured according to a method proven to be accurate and repeatable.

7.3 Clinical Studies

Clinical studies shall be conducted in accordance with the general requirements of ISO 14155.

7.4 Post-Market Follow-Up

Post-market performance of joint replacement implants shall be evaluated.

NOTE. Appropriate methods include survival analysis (with revision as the endpoint) and clinical evaluation. If available, relevant information from joint replacement registrations shall be considered.

8.1 General

The requirements of Clause 8 of YY/T 0640-2016, and the particular requirements of 8.2 to 8.4, apply to this document.

8.2 Metallic Surfaces

All metallic components shall be polished using iron-free polishing agents. Clean, degrease, rinse, and dry all components, and visually inspect the joint surfaces with normal or corrected vision. The surface shall be free of any defects that could affect implant functions, and shall also be free of finishing deposits and other contaminants.

NOTE. Defects affecting functions include oxide scale, stab marks, small notches, scratches, cracks, dents, burrs, and other defects.

8.3 Plastic Surfaces

The articular surfaces of plastic components shall not be prepared using non-removable abrasives or polishing agents. Clean, degrease (if necessary), rinse, and dry the components,

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