A study of customized implant for revision hip replacement
Reviewed by Kate Anderton, B.Xc. (editor)
A team of scientists from the Advanced Manufacturing Technologies Center of the National Technology Initiative (NTI) of Peter the Great St.Petersburg Polytechnic University (SPbPU) (head — Prof. A.I. Borovkov, the Vice-rector for Advanced Projects of Peter the Great St. Petersburg Polytechnic University) developed a mathematical model of an “endoprosthesis-skeleton” system. Special attention was paid to the geometry and internal structure of hip bones. Using advanced computer modeling technologies, the team assessed the integrity of the biomechanical structure for a typical case (a patient standing on two legs). Currently the team is working on a methodology that would reduce the time of such analysis to several days. The results of the study were published in the Vibroengineering PROCEDIA journal and phttps://www.riverasurgical.com/wp-admin/post-new.php#resented at the 12th All-Russia Congress on Fundamental Issues of Theoretical and Applied Mechanics.
Hip joint arthroplasty is a relatively common procedure today. During arthroplasty the upper part of a patient’s hip bone is replaced with a metal stem with a spherical joint element, and a cup to allow the head of the joint to rotate inside the pelvis. Medical companies manufacture standard elements with different parameters for ordinary hip replacement operations. However, after some time a certain share of patients experiences issues with implants and requires their replacement.
As a rule, this happens due to the insufficient (or excessive) load the endoprosthesis puts on the hip bone causing its tissue to change. Moreover, bone strength can be affected by osteoporosis and other diseases. By the time of the second surgery (the removal of the initial implant and the installation of a revision one) a part of the hip bone becomes unfit as it is unable to bear the load. Therefore, when a patient comes to a secondary operation with a damaged hip bone, standard implants are of no use for them, and a regular cup (even if it is of a bigger size) might not work.