Case Study

Technology that enables complex knee surgery to be personalised for each individual has been successfully trialled in patients for the first time. The ‘TOKA surgical system’ – supported by the IKC during its early development – is set to enter a larger UK trial later this year.

TOKA aims to improve outcomes for high tibial osteotomy (HTO) operations. These are used in younger osteoarthritis patients, to realign the knee and take pressure off damaged areas of the knee joint, as an alternative to total joint replacement. The upper part of the shin bone is essentially cut and wedged open using a metal plate, to change the angle between the knee and ankle and reduce pain in the joint.

The success of the operation is dependent on correct realignment, but this is often difficult for surgeons to assess during the procedure. Off-the-shelf metal plates also cannot ensure the best fit for all patients.

TOKA uses 3D imaging techniques and software alongside the patient’s CT scans to plan each procedure individually in advance. The process prints a 3D personalised surgery guide for each patient to help surgeons achieve the optimum angle and positioning together with a personalised 3D printed titanium plate implant to fix the patient’s shin bone in place. The technology was developed by Professor Richie Gill and Dr Alisdair Macleod from the University of Bath, knee surgeons from the Royal Devon & Exeter Hospital and Alberto Casonato from 3D Metal Printing Ltd. The IKC supported the team to further develop and patent the technology and helped in their applications for further funding.

TOKA was used in HTO with 25 patients in Bologna, Italy, during 2020 and these patients have already undergone their standard 12 week and six month follow ups. The full data is still being analysed, but interim results look very positive, according to Professor Gill.

“Having everything pre-planned allowed the surgeons to work much more quickly, reducing operation times from up to 90 minutes to just 30,” he said. “Patients also tended to spend less recovery time in hospital. Some are already getting in touch with the surgeons to ask if their other knee can be done in the same way!”

Because TOKA creates a 3D plan of how the bones should align following surgery, it is possible to assess very accurately whether the desired alignment has been achieved, by comparing these plans to post-surgery CT scans. The team have been developing the software to enable this comparison to be done automatically.

UK trial

Five patients in the UK have also had high tibial osteotomy (HTO) using TOKA, as part of a pilot study in advance of a full scale randomised controlled trial due to start later in 2022. Funded through Versus Arthritis, the trial will recruit 88 patients to compare the use of TOKA with a standard HTO.

TOKA is the second technology supported by the IKC Versus Arthritis partnership to enter clinical trials. The £2m funding awarded through the partnership has supported 22 projects overall, leading to two technologies being patented and two undergoing regulatory approval.

Angela Davies, Head of Research Engagement at Versus Arthritis said: “Osteoarthritis affects millions of people, making it the most common type of arthritis in the UK. At Versus Arthritis, we never stop looking for better ways to treat osteoarthritis early, to stop it in its tracks. This research shows great promise for improving treatment, particularly in younger people with osteoarthritis, with potential to delay or completely remove the need for joint replacement surgery.

We’re delighted that this technology is progressing in human clinical trials in the UK. This is evidence of how innovative researchers in collaboration with Versus Arthritis and the IKC can push research forward to bring real benefit for people with arthritis.”