Hungarian (formal)
Research Other research topics

The effect of lubricants to the stability of spinal implants

In this complex project we examine the stability of the spinal implants related to the ambient material and the tightening torque of the fixing screws.

As the first step we determined the relative lubricating properties of some human materials that are exist during a spinal operation. For the measurements a special machine was built to measure the relative lubricity. In this way we compared the lubricity of the human materials like blood and fat to some well-known lubricants.

The set-up of the lubricity measuring device The set-up of the lubricity measuring device

 

The prototype we used during the tests The prototype we used during the tests

 

Tiba Zs, Husi G, Manó S, Kiss L, Jónás Z, et al. An easy to use device for lubricity examination. Biomech Hung 2009;II(2):27-30.

After contructing the device for the measurements we executed the comparative measurements with the following result.

Result of the lubricity measurements Result of the lubricity measurements

 

Based on these results we chosen the industry equivalent lubricant material for the spinal implant tests, so we used motor oil as this has the most similar lubricity to the human materials.

During the mechanical tests described in the standard ASTM F-1798 we compared the dry is the lubricant based, furthermore the weakly is the strongly tightened implants based on the force required to move the components relatively.

Mechanical spinal implant tests with and without lubricant Mechanical spinal implant tests with and without lubricant

Mechanical test of spinal implant Mechanical test of spinal implant

 

The last sub-project is a measurement sequence where we ask spinal surgeons to tighten the screws of spinal implants using a plastic model. With this experiment we would like to see how much is the really applied torque to these implants and compare the manufacturer's suggestions and the results of the previous sub-projects.

Our model to measure the tightening of spinal implant screws Our model to measure the tightening of spinal implant screws

General information

Parent department:
Department of Orthopaedic Surgery, University of Debrecen

Address:
H-4032 Nagyerdei krt. 98, Debrecen, Hungary

Phone:
+36 52 411 717/56983

Fax:
+36 52 255 814

E-mail:
biomech@med.unideb.hu

Web:
www.biomech.med.unideb.hu