Researchers design new hip replacements

MONTREAL, Nov. 2 (UPI) -- Scientists at McGill University have developed hip replacements they say last longer and create fewer problems than conventional models.

The new hip replacements contain an implant designed to "trick" the host bone into remaining alive by imitating the porosity of real bones. While the product is actually less dense than its counterparts, the designers stress it is just as effective.

"Because the implant loosely mimics the cellular structure of the porous part of the surrounding femur, it can 'trick' the living bone into keeping on working and staying alive," designer Damiano Pasini explained in a press release. "This means that our implant avoids many of the problems associated with those in current use."

A paper detailing tests on the hip replacement was published in the Journal of Orthopaedic Research. During the study, the researchers found a degree of stress is necessary to stimulate cell formation. Without this, bone material living in the femur becomes reabsorbed by the body, eventually deteriorating the bone.

"What we've done throughout the femoral stem is to replicate the gradations of density found in a real femur by using hollowed-out tetrahedra," Pasini added. "Despite the fact that there are spaces within the tetrahedra, these forms are incredibly strong and rigid so they're a very efficient way of carrying a load."