Sunday, January 16, 2011
Podium and poster presentations at the March 2010 American Association of Orthopedic Surgeons reviewed size, design and position of the implant cups to determine critical factors leading to metal ion release and other complications of hip surgery.
There were two podium presentations of interest both moderated by Tomas Schmalzried MD, a co-inventor of this hip and one poster presentation.
The first presentation reviewed 585 patients with hip resurfacing procedures from a study conducted in the UK. They found that only femoral cup size and cup inclination were found to effect ion levels. Consistent with other findings, the smaller the cup size, the higher the metal ion levels.
The second presentation reviewed 31 patients who had pseudotumors as a result of the hip replacement and found that positioning of the implant outside certain areas of orientation were more likely to develop these psudotumors. There is an optimal placement which will result in fewer pseudotumors.
The third review was a poster presentation involving hip resurfacing conducted in the UK with 90 patients. The objective was to review the metal ion levels in these patients based on different surgical variables. They found a similar result as the first study in one respect and a different finding in another respect. The larger the femoral head and cup diameter resulted in decreased levels of metal ions in the whole blood of patients. In contrast to the first study, they found that the inclination of the cup had no effect on the concentration of metal ions.
Posted by Connie at 10:42 AM