YY/T 1655-2019Implants for osteosynthesis—Standard test method for measuring fretting corrosion of osteosynthesis plates and screws (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard is prepared using the redrafting method with reference to ASTM F897-13 "Test Method for Fretting Corrosion of Plate and Bone Screws".

1 Scope

This standard specifies a contact area for determining the bone plate and bone screw in osteosynthesis (fracture internal fixation) due to occurrence A screening test method for the amount of metal loss caused by fretting corrosion. The test was performed in the manner of clinical use of the implant. Testing machine makes bones The plate and bone screws move relative to each other to simulate a form of motion that may occur during clinical use.

This standard can be used to test the fretting corrosion of metal plates and metal bone screws of the same or different alloy compositions, also suitable for testing Metal-non-metal combination. This standard can also be used for the study of wear and degradation of non-metallic materials. In addition, this standard can be used as saline and a grading screening test method for the corrosive action of protein solutions, or for classifying the ability of metal-metal combinations to resist fretting corrosion, or To study other material combinations.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

YY 0017 bone cement implant metal plate

YY 0018 bone cement implant metal bone screw

3 Overview of test methods

A two-hole plate is attached to the two plastic rods by a bone screw, and a resilient gasket is placed between the bone plate and the rod to place it in a glass In the glass beaker, the beaker is sealed with an elastic rubber cap. The assembly is steam sterilized and then the sterile solution is injected through the rubber cap to the burn cup. Mounting the assembly to a micro-motion device that produces a rocking motion, causing a slight periodicity of the mating surfaces of the plate and the screw Displacement. At the end of the test, the amount of fretting corrosion was obtained by measuring the mass loss of the bone plate and the bone screw and analyzing the chemical composition of the solution. test See Appendix A for the test principle.

4 Significance and application

4.1 By examining the condition of the implant after use, it can be known that the bone plate and bone screw used in the osseointegration are due to the plate-nail interface.

Corrosion can cause metal loss. One of the principles of corrosion is due to the relative motion (flicking) of the screw head and the plate hole contact surface. Dynamic corrosion.

4.2 The release of corrosion products into the tissue surrounding the implant may cause adverse reactions or systemic effects on the local tissue. Therefore, minus Corrosion products in very small tissues are very important.

4.3 Screws and plates can be configured differently as long as they comply with YY 0018 and YY 0017. This standard can be used to evaluate different snails The impact of the nail and plate combination design. As new materials and product designs continue to emerge in fracture treatment, identify these new improvements to fretting The effect of the amount of metal loss from corrosion is very important.

4.4 This standard provides a standard screening test method for classifying the ability of metal plates and screws to resist fretting corrosion.

And determine the effect of different solutions on the rate of fretting corrosion.