Popular Hip Prosthesis Show Long-Term Durability

In the present report, a total of 73 patients (75 hips) were available for follow-up, with a further 12 patients lost to follow-up since 2006. The main outcome measures were stem loosening and durability of the implant.

The results showed an absence of aseptic femoral stem loosening and a poor rate of survival of the threaded cup. The researchers observed osteolytic lesions around the proximal part of the femoral component on twenty-four (47%) of fifty-one radiographs, but no stem was deemed at risk for loosening. The probability of survival of the stem at twenty years was 0.96, and the probability of survival of the cup at twenty years was 0.67. The study was published in the September 2012 issue of the Journal of Bone and Joint Surgery.

“This shows that the fear over hip prostheses is unfounded. It is better to live with a prosthesis and without pain than to live without one and be in pain,” siad Reinhard Windhager, MD, head of orthopedics at the Medical University of Vienna.

The Zweymüller prosthesis, developed at the Medical University of Vienna by orthopedic surgeon Prof. Karl Zweymüller, MD, over 30 years ago, has a femoral stem with the shape of a tapered, rectangular implant, and was one of the first to be anchored in the bone without using bone cement for fixation, relying instead on the stem’s geometry and roughened surface features to provide stable anchoring and natural integration into the bone. While in the past the endoprosthesis was made from ultra-lightweight titanium, further revisions are now used in combination with a ball and socket made from ceramic, which produces less wear.

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Medical University of Vienna