High tech implants to aid facial reconstruction

Aug 27 2004

Loughborough University researchers have been awarded more than £200,000 to develop state-of-the-art tailor made implants for people requiring facial reconstructive surgery.

The Department of Health’s ‘New and Emerging Applications of Technology’ (NEAT) funding programme has awarded the University £234,761 for the 2 year project, which is being led by Dr Russell Harris of the Wolfson School of Mechanical and Manufacturing Engineering.

The aim of the work is to research and develop a technique that will provide the rapid and direct manufacture of tailor made implants for bone replacement and tissue growth. The project could help a wide range of people, including victims of bone disease, oral cancer, congenital defects and traumatic injuries.

Patients currently requiring reconstructive surgery may have to wait several weeks for a customised implant to be made. This is because, with conventional manufacturing techniques, implants have to be moulded, cut, or formed, which is time consuming and costly. These conventional techniques also impose geometrical restrictions on the shapes that can be produced and means the fit and placement of implants may be compromised.

The implant production method being investigated by Dr Harris is called Laser Sintering, which belongs to a family of techniques known as Rapid Prototyping (RP). The use of RP allows physical parts to be created immediately, directly and automatically from a 3D representation, known as a 3D computer-aided-design (CAD) model. It works by breaking down a 3D model into 2D sections which are built up layer by layer by high tech machines. In Laser Sintering the 2D layers are built up by selectively binding powder particles together using a laser in just a few hours.

Data from CT or MRI scans of facial injuries are utilised to create a 3D model of the required implant. This means that the implant would be tailor made to fit exactly to a patient’s requirements in terms of shape, performance and integration into existing structures within the body, using data collected by non-intrusive scans.

The new implants would be made from a mixture of a polymer and a bioactive ceramic. Bioactive ceramics are used for bone implants and tissue scaffolds due to their ability to bond with natural bone. An important such material, hydroxyapatite, can be combined with polymers to form a material with appropriate stiffness, toughness and bioactivity for use in the body.

Dr Harris said: “The requirement for bone replacement/reconstruction due to traumatic injury or radical surgery has, of course, long been required by patients. And materials have now been developed that are capable of bonding with natural bone to allow such repair.

“Through research and development these materials could be harnessed with a high tech but established production technique for the direct, quick, custom manufacture of bone implants that will integrate themselves within the body, and require only one surgical operation. This new technique would reduce patient distress; patient risk; operative procedures; costs and waiting times, whilst increasing implant performance.

“The realisation of such implant production techniques would revolutionize the application and possible treatment routes for the immediate and long term benefit of patients, clinicians and healthcare providers.”

Dr Harris will be working with several other organisations on the project, including Queen Mary University of London, University College London and the Facial Surgery Research Foundation, Saving Faces.