ASTM F2193 encompasses varied test annexes to determine the strength, stiffness, and durability of spinal screws.
ADMET’s eXpert 2600 will perfom the following tests.
A1 Metallic Spinal Screws– describes the specification for metallic spinal screws. The Classification, Marking, Packaging, Labeling, and Handling as well as a variety of designations that define this specification. For a full listing go to www.astm.org.
A2 Metallic Spinal Plate Bend Testing
-Determine Spinal Plate structural stiffness, bending yield moment, bending ultimate moment, bending fatigue runout moment. This annex references ASTM F382 for Fatigue runout and bending moment. MTESTQuattro Torsion is a servo controlled data acquisition, analysis, and reporting PC based control system that will obtain the above data, store, analyze, and generate reports for review.
-Configure 4 point bend fixture are in accordance with table below;
|Thoracic and Lumbar||76.00||76.00|
- Sample size determined by practice ASTM E122.
- Load the test specimen at a constant rate of speed to failure
- Record max load at failure
- Apply Sinusoidal cyclic loads in load control at an R ratio of for lumbar,thoracic devices, and cervical spine regions.
- Run test at constant frequency
- Determine fatigue maximum moment levels from static test. % of bending ultimate moment.
A3 Metallic Spinal Rods
-Determine Spinal Rod’s bending structural stiffness, bending yield moment, bending ultimate moment, bending fatigue runout moment, and bending fatigue according to ASTM F382.
- Using “V” Notched Roller for the top of the fixture, apply axial load at a constant rate of speed until failure.
A4- Measuring the Static and Fatigue Bending Strength of Metallic Spinal Screws
-Determines characteristics of the spinal screws needed for procedures and not the performance of the spinal screws. Prepare apparatus according to Figure 4.2- www.ASTM.org
- Use ADMET eXpert 2600 constant displacement rate- apply tensile or compressive load. Use MTESTQuattro for profile set up, realtime xy plot, analysis bending/stiffness and more.
- Apply loads of increasing magnitude and generate load vs. displacement curve at a constant rate of speed.
- When load changes sign, beyond the linear elastic region, end the test.
- Record failure load at failure and comment.
More detail included in full specification found at www.astm.org