Tens of thousands of early knee osteoarthritis sufferers may find relief in a new treatment that uses personalised 3D metal implants. Engineers from the University of Bath’s Centre for Therapeutic Innovation (CTI), UK, have finessed 3D printing technology to develop unique medical-grade titanium-alloy plates that are more stable and safer to use than generic steel plates.

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Many with osteoarthritic knees undergo a surgical procedure known as a high-tibial osteotomy (HTO) to realign the knee and redistribute weight – a stabilising plate is usually inserted for this purpose. However, in the experimental new Tailored Osteotomy for Knee Alignment (TOKA) procedure, engineers have successfully improved the operating procedure and duration of HTO surgery with the 3D metal plates. The new plates were safely tested in a computer-based trial.

After a 3D scan of the affected knee, patients will receive a personalised 3D printed surgical guide and plate, which will simplify the surgery and improve surgical accuracy.

“The HTO surgery has a long clinical history and has very good results if done accurately. The difficulty surgeons have is achieving high accuracy, which is why we have created the TOKA method, which starts with a CT scan and a digital plan,” said Professor Richie Gill, CTI.

“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 should go.” The pre-planning element greatly simplifies surgery and could cut time on the operating table from two hours to around 30 minutes.”

TOKA could additionally result in better knee alignments, increased stability of the joint, and less discomfort for the patient.

A TOKA trial has already begun at the Rizoli Institute in Bologna, Italy; at least 25 patients have already received new personalised printed metal plates. Another randomised controlled trial is expected to take place later this year, involving hospitals in Bath, Bristol, Exeter and Cardiff.