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I would appreciate if anyone can suggest useful equipment and procedure for the testing of spinal implants.

Question:
I would appreciate if anyone can suggest useful equipment and procedure for the testing of spinal implants.


Answer:
I believe there is an ASTM standard for fatigue/ static testing of spinal fixation systems, although I haven't got the number to hand. You should have a look to the ASTM Standards (American Society fot Testing and Materials). They have a whole set of standards about spinal implants testing. (Which are currently proposed as ISO standards).You have to make various fixtures to hold the parts, which are defined in the standards. Depending on your material and the parts you are testing, you may need a temperature controlled water bath and circulating system to immerse the components in Ringer's solution or similar while you test them. For polymers or composites, you will need to soak them before testing.have you looked at the protocols being developed by ASTM Committee F04 on Medical Devices? ASTM is in West Conshohocken, PA and you can reach their WEB page to get names and e-mail addresses by accessing www.astm.org. I just realized that I only answered half of your question in my first message. We test spinal implants using test machines from MTS Systems Corporation and I know that they have developed some special fixturing for theit Mini-Bionix machine to assist in spinal testing. They can be reached by e-mail at lito.me...@mts.com (Lito Mejia, Biomaterails Testing Systems) or: MTS Systems Corporation 14000 Technology Drive Eden Prairie, MN 55344-2290 612-937-4000 FAX: 612-937-4515 I have tested spinal implants in porcine spinal segments in torsion, compression and fatigue. Basically the spinal segment consists of two vertebrae and one intervertebral disc. A discetomy is performed to remove the disc nucleus, and the replacment disc inserted. The spinal segment is then mounted inbetween two holding jigs using both screws and a medical cement (dental or bone cement) set around the cut ends of the two vertebrae A compressive load is applied, using typically a MTS or Instron testing machine, and if you have the capability, a rotation can be applied for several cycles to simulate fatigue loading. The magnitude of loads depends on your model (animal or human cadaver), which values can readily be found in the literature. If you want to test the implant on its own, that depends on what your artificial disc is made of.



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