Researchers at the University of Bath in the UK created a framework for 3D printing personalized high-tibial osteotomy (HTO) plates, using a titanium alloy, for knee realignments in osteoarthritis patients. The plates should fit nearly perfectly when implanted thanks to the new approach. The researchers have also developed an improved surgical technique, the TOKA (Tailored Osteotomy for Knee Alignment), which they claim should improve the fit of the HTO on the knee and significantly speed up HTO surgery from two hours to approximately 30 minutes.
“Knee osteoarthritis is a major health, social and economic issue and does not receive as much attention as it should. A quarter of women over 45 have it, and about 15 percent of men, so it’s a significant burden that many live with,” said Richie Gill, a researcher involved in the study, in a press release. “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.”
To begin the procedure, patients undergo a 3D CT scan of the knee, and these data are then used to manufacture a personalized HTO and surgical guide that fit their shin bone perfectly. The 3D-printing process relies on a metal printing technique that results in medical-grade titanium-alloy plates. The manufactured surgical guide helps to simplify and speed up the surgery. As the implants fit the patient perfectly, they are intended to reduce discomfort post-surgery and can be implanted in earlier stage patients.
“The HTO surgery has a long clinical history and it 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 digital plan,” said Gill. “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. In addition to a surgeon being able to precisely plan an operation, a surgical guide (or jig) and a plate implant, each personalized 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.”
After a virtual trial, where the researchers used in silico modeling with CT data from 28 patients to assess the potential of the technique, the device has got the go-ahead for a real-life trial in the UK.
Here’s an animation showing some of the differences between the TOKA implants and conventional ones:
Study in journal Communications Medicine: Personalised high tibial osteotomy has mechanical safety equivalent to generic device in a case–control in silico clinical trial
Via: University of Bath