YY/T 0119.2-2014 Spinal implants - Components of spinal internal fixation systems - Part 2: Metal spinal screws

1 Scope

This section of YY/T 0119 specifies the classification of metal spinal screws Materials, requirements, and performance.

This section applies to anchoring elements in spinal internal fixation implants.

2 S Normative References

What are the applications of the following documents for this document. For all referenced documents with dates, only the version with dates is applicable to this document. Any referenced document without a date, including all versions, shall apply to this document.

YY/T 0119.1-2014 Spinal Implants - Internal Fixation System Components - Part 1: General Requirements

YY/T 0119.5-2014 Spinal Implant Human Spinal Internal Fixation System Part 5: Static and Fatigue of Metal Spinal Screws

Test method for determining bending strength

ASTM F 543 Specification and test methods for medical bone screws

ASTMF 1839 Standard material for testing orthopedic devices and instruments - dramatic polyurethane foam for use as a standard material for testing orthopedic devices and instruments

3 Categories

3.1 Classify spinal screws according to the classification method specified in ASTMF543.

3.2 Spinal screws can also be classified based on their ability to interconnect with other components of the spinal internal fixation system, such as expansion head screws, locking screws, and self-locking screws.

4 Materials

Select spinal screw materials according to the requirements and recommendations in Chapter 5 of YY/T 0119.1-2014.

5 Requirements Performance and testing methods

5.1 Geometric Characteristics

The recommended dimensions for metal spine screws can be found in ASTM F 543

5.2 Rotating Connection

The recommended spinal screw rotation slots can be found in Appendix A6 of ASTM F 543

5.3 Torsion performance

Determine the torsional strength performance (yield torque, maximum torque, and fracture torsion angle) of wax nails according to the test method of ASTMF543.

5.4 Rotation knob torque

5.4.1 Test requirements

The rotational torque (in and out torque) of self tapping spinal screws and self drilling spinal screws shall be determined according to the test method in Appendix A2 of ASTMF 543, and the test method shall comply with the requirements of 5.4.2.

5.4.2 Test Methods

5.4.2.1 Adopt requirements that comply with ASTMF 1839 A rigid polyurethane test block with a grade of 40 shall be made, and the length of the test block shall not be less than the penetration depth of the test.

5.4.2.2 Conduct a torque test at rotational speed.

5.4.2.3 Conduct tests on specific screws to determine the rotational torque of the longest end screw of the embodied spinal screw Until the screwing depth of the screw is equal to the thread length.

5.4.2.44 Conduct a comparative test on the performance of screws by measuring the rotational torque until the depth of penetration is equal to the best known value of the available thread length in the group.

5.5 Axial pull-out force

5.5.1 The experiment is coming

According to the standard test method in Appendix A3 of ASTMF543, the axial pull-out force of screws should be determined, and the test method should meet the requirements of 5.5.2.

5.5.2 Test Method

5.5.2.1 Use rigid polyester grade 20 that meets the requirements of ASTM F 1839 to make test blocks.

5.5.2.2 Rotate each screw into the test block at a speed of 30 rhmin,

5.5.2.3 Conduct a test on a specific end screw, that is, rotate the shortest screw in the spinal screw of the humanoid type until the screw's rotation depth is equal to the thread length. .

5.5.2.4 Conduct a sensitivity test on the screw performance by screwing each spinal screw until the screwing depth is equal to the shortest available thread length in the screw control group.

We recommend a bone screw performance tester for testing from 5.4 to 5.5 to 5.6

5.6 Bending performance

The test force method described in YY/T 0119.5 is used to determine the bending structural stiffness, fatigue moment, ultimate bending moment, fatigue termination bending moment, and median fatigue bending moment of the screw after 2500000 cycles.

6. Information provided by the manufacturer

The information provided by the manufacturer shall comply with the requirements of YY/T 0119.1-2014 and shall also include the following:

a) The size of spinal screws can be named according to the requirements of Chapter 3 of YY/T 0119.1-2014:

b) In addition to the requirements of 10.2 in YY/T0119.1-2014, the label of spinal screws should include the diameter of the screw (when the label size allows);

c) In addition to the packaging information included in Chapter 9 of YY/T 019.1-2014, the screw diameter and screw length should also be included.

Puchuang bone screw performance tester is a multifunctional integrated instrument developed for medical bone screw performance testing. It can perform related tests on bone screw driving torque, self tapping performance, torsion performance, and pull-out performance.

The bone screw performance tester can be widely used in medical device testing institutions, medical device manufacturing enterprises, and other units.

Acceptance Criteria:

Appendix A

(Informative Appendix)

Basic Principles

A. This appendix aims to provide terminology related to spinal screws Practical and unified information related to performance, testing methods, and application of spinal screws.

Chapters 3 to 5 provide classification and terminology, material standards, geometric definitions, size and performance definitions for ridge screws, respectively.

A. The following mechanical properties of spinal screws are crucial for surgeons for the following reasons:

a) Maximum torque - This feature determines the ultimate torsional capacity of spinal screws, which is particularly important for self tapping and self drilling screws. When screws are screwed into dense cortical bone, the type of these screws has the potential to load the screws to the torsional limit.

b) The requirements for rotational torque determine the potential level of torque that the screw can withstand during the screwing process. This feature is particularly important for self tapping and self drilling screws. When screws are screwed into dense cortical bone, the type of these screws has the potential to load the screws to the ancestral limit.

c) The bending performance is an important characteristic of self column screws, as screws are the main pathway for transferring soft loads from longitudinal elements to bones. In addition, the bending stiffness of screws may directly affect the healing rate and fusion ability.

d) Axial pull-out force - Axial pull-out force is an important characteristic of spinal screws, as screws are the main pathway for transferring loads from longitudinal elements to the bone

A. 3 The rotation torque test in this part requires that the screw be screwed into the test block of rigid polyurethane foam with grade 40 in accordance with ASTMF 1839. The selection of this grade of material is based on two reasons

a) The material is very similar to cortical bone, therefore typical clinical trial results will be provided;

b) The reference material provides a unified material for the experiment.

A. The output force test in this section requires the spinal screw to be screwed in accordance with the requirements of ASTMF 1839. In the test block of rigid polyurethane with a grade of 20. The selection of materials of this grade is based on two reasons;

a) The material is very similar to cancellous bone, therefore typical clinical test results will be provided:

b) The reference material provides a unified material for the experiment.

A. Rotate the spinal screw into the test block to the specified depth, which is related to the specific experiment. For the rotary torque test, choose the maximum screw in depth, and for the axial pull-out force test, choose the minimum screw in penetration, because each situation represents the clinical situation of the relevant performance test.