Stryker told doctors that the multi-part modular design of the Rejuvenate would provide better surgical results because they would be able to get better adjustment of angle and lengths during surgery. This representation sounds logical because it was sometimes difficult for surgeons to get the exact angles and leg lengths that they would prefer with the two part hip implants.
However, Stryker never properly tested this theory on people before its massive sales campaign to promote the Rejuvenate. Stryker tested the idea in a laboratory which is far different from observing how the devices function when implanted in people. Testing a product in a laboratory is also far different than conducting a proper scientific clinical study to develop scientific facts that can be reported.
A recent medical paper from the 2012 American Association of Orthopedic Surgeons meeting reported that “there is currently no clinical evidence that the use of modular necks is associated with improved function or reduced consequences of femoral-pelvic impingement.” This means that there is no scientific evidence that the theory of improved outcomes with these multipart or modular implants actually works in practice. It is just a theory and a sales pitch to sell more of the Stryker implants. Stryker never did clinical (that means on people) studies to see if the purported benefits of this product could justify the known risks of incorporating multiple metal junctions in a product designed to be implanted in the human body.