TOKA (Tailored Osteotomy for Knee Alignment) was developed by engineers at Bath University’s Centre for Therapeutic Innovation (CTI). It uses a 3D CT scan of a patient’s knee to develop a personalised 3D printed surgical guide and plate, made from medical-grade titanium-alloy. Surgeons will then insert this high-tibial osteotomy (HTO) plate, realigning the patient’s knee to reduce stress and pain in the joint. It’s claimed the customised plates will be a better fit than generic plates and will also simplify HTO procedures. The
“Knee osteoarthritis is a major health, social and economic issue and does not receive as much attention as it should,” said Professor Richie Gill, from Bath’s CTI. “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.”
The 3D printed plates have already been tested virtually, in a computer-based trial using CT scan data from 28 patients. The so-called ‘in-silico’ clinical trial, described in the journal Communications Medicine, is said to be the first of its type to demonstrate the safety of an orthopaedic device.
Once elective surgeries restart in the UK, in-vivo trials are due to take place in hospitals in Bath, Bristol, Exeter and Cardiff as part of a randomised control trial to compare patient outcomes with an existing generic HTO procedure. The technique has already been used successfully in Italy, where 25 patients have received personalised HTO plates as part of a trial at the Rizzoli Institute in Bologna.
“3D printing the custom knee implant and doing the scanning before operating means surgeons will know exactly what they’ll see before operating and where the implant will go,” Professor Gill continued.
“In addition to a surgeon being able to precisely plan an operation, a surgical guide (or jig) and a plate implant, each personalised to the patient, can be 3D printed automatically based on the scanning data. Importantly this type of treatment relieves the symptoms of knee osteoarthritis while preserving the natural joint.”