3D printing simplifies high tibial osteotomy

Engineers at the University of Bath’s Centre for Therapeutic Innovation (CTI) working with 3D Metal Printing Ltd, are using the TOKA (Tailored Osteotomy for Knee Alignment) treatment to improve the surgical procedure and fit of high-tibial osteotomy (HTO) plates to realign a patient’s knee. The system improves stability, comfort and weight bearing over existing generic plates. The technique also simplifies high tibial osteotomy (HTO), making operations quicker and safer.

The HTO plates have been safety tested in a computer-based virtual ‘in-silico’ trial using CT scan data from 28 patients. The in-silico clinical trial, globally the first to demonstrate the safety of an orthopaedic device, modelled the stresses that would be exerted on the bespoke plates and showed these would be comparable in safety to the standard treatment.

‘Knee osteoarthritis is a major health, social and economic issue and does not receive as much attention as it should,‘ Professor Richie Gill, from the Centre for Therapeutic Innovation, pointed out. ‘A quarter of women over 45 have it, and about 15 percent of men, so it’s a significant burden that many live with. Knee replacement is only useful for end-stage osteoarthritis, so you can be in pain and have to live with a disability for a long time, potentially decades, before it’s possible. We hope that the new TOKA process we’ve developed will change that.‘

Knee osteoarthritis patients receiving TOKA treatment will undergo a 3D CT scan of their knee, before a personalised 3D printed surgical guide and plate, both shaped to their tibia (shin bone), is created. The surgical guide simplifies the surgery and is designed to improve accuracy. The process also sees the first implementation of 3D printed screw threads into the HTO plates, meaning they can be optimally positioned to help secure them against the bone.