MEDICAL DEVICES
number of shapes and sizes . “ It is unlikely patients will receive an implant that fits them accurately ,” he concedes . “ This can cause poor physical function and contribute to loosening . Poor physical function can also occur because of stress shielding – the process whereby metal implants remove stress from the patient ’ s bone . The bone responds by reducing in density and therefore becomes weaker .”
Parkes also highlights the increasing incidence of obesity as one of the reasons why joint replacements are becoming more common in young people . “ This poses longevity issues as implants can reach their maximum lifespan and need replacing several times during the patient ’ s lifetime ,” he says . “ To combat these issues , researchers and engineers have been developing implants in new ways , using techniques such as additive manufacturing ( AM ). The technology aims to improve the form , fit and function of implants .”
AM , also known as 3D printing , offers exciting opportunities to develop new technologies across industry sectors . It can remove many of the constraints seen in more traditional manufacturing methods such as milling , casting or fabrication . This opens up new possibilities for complex geometries and mass customisation of parts , at a commercially viable cost , that were
3D CAD image of a hip x-ray , smart implants are changing medicine
34 April 2018