16-02-2006, 01:08 AM
<b><!--sizeo:5--><!--/sizeo-->Effect of Preheating on Implant-Cement Interface Strength for Hip Replacement<!--sizec--><!--/sizec--></b>
<b>P. Paczocha and J. E. Indacochea</b>
Copyright AD-TECH; licensee AZoM.com Pty Ltd.
Posted: September 2005
<b>Abstract</b>
Research continues worldwide on methods to improve the efficiency and integrity of hip replacement procedures. Each component of the procedure is being investigated on their own merit, as well as a function of its interaction with its mating part. For the cemented procedure, the three major items being studied are bones, alloys used to replace the original hip joint, and the bone cement used to anchor the components. The present investigation focused on the insertion procedure of the implant into the cement, particularly with the objective of speeding up the surgical procedure. The polymethylmethacrylate (PMMA) bone cement and a Cobalt-Chromium metal alloy were used in this study. Following a standard mixing procedure for cement preparation in vacuum, the metal inserts were preheated to different temperatures before the insertion into the cement mantle. The samples were evaluated by conducting compression shear tests and a microscopy analysis of the cement surface in contact with the implant after the failure. Compression shear strength graphs were generated and the results showed a drop in shear strength of the cement/implant interface, as the preheat temperature of the metal implant increased. Some of the voids found in the cement mantle were caused by preheat of the metal insert; they changed in terms of volume and shape. The interface strength decreased as the volume and size of the voids increased.
<b>Keywords</b>
Total Hip Replacement, PMMA Cement, Metal Insert, Implant-Cement Interface, Shear Strength
<b>P. Paczocha and J. E. Indacochea</b>
Copyright AD-TECH; licensee AZoM.com Pty Ltd.
Posted: September 2005
<b>Abstract</b>
Research continues worldwide on methods to improve the efficiency and integrity of hip replacement procedures. Each component of the procedure is being investigated on their own merit, as well as a function of its interaction with its mating part. For the cemented procedure, the three major items being studied are bones, alloys used to replace the original hip joint, and the bone cement used to anchor the components. The present investigation focused on the insertion procedure of the implant into the cement, particularly with the objective of speeding up the surgical procedure. The polymethylmethacrylate (PMMA) bone cement and a Cobalt-Chromium metal alloy were used in this study. Following a standard mixing procedure for cement preparation in vacuum, the metal inserts were preheated to different temperatures before the insertion into the cement mantle. The samples were evaluated by conducting compression shear tests and a microscopy analysis of the cement surface in contact with the implant after the failure. Compression shear strength graphs were generated and the results showed a drop in shear strength of the cement/implant interface, as the preheat temperature of the metal implant increased. Some of the voids found in the cement mantle were caused by preheat of the metal insert; they changed in terms of volume and shape. The interface strength decreased as the volume and size of the voids increased.
<b>Keywords</b>
Total Hip Replacement, PMMA Cement, Metal Insert, Implant-Cement Interface, Shear Strength