Knee osteoarthritis affects around 10% to 14% of adults in the United States. In the United Kingdom, the estimated prevalence is even higher at 15% to 19% of individuals over age 20. Knee Osteoarthritis causes debilitating chronic pain and loss of mobility that affect overall physical and mental health and quality of life. Engineers at England’s University of Bath Centre for Therapeutic Innovation have now developed a bespoke 3D printed knee implant that could significantly enhance outcomes for knee replacement procedures.

The device is known as the Tailored Osteotomy for Knee Alignment (TOKA). Following a computerized “in-silico” (computer simulated) trial demonstrating the safety of the device, it received approval from Britain’s Medicines and Healthcare products Regulatory Agency (MHRA). MHRA approval cleared TOKA for clinical trials, meaning study participants could soon start receiving personalized titanium knee implants. 

TOKA is designed for use in high tibial osteotomy (HTO) surgery, which involves metal plates and screws that realign deformities of the tibia associated with osteoarthritis. Currently, only patients with end-stage knee osteoarthritis are candidates for HTO, a procedure that now takes about two hours to complete. TOKA makes that treatment available in earlier stages of the disease. Early access to knee replacement could help younger osteoarthritis patients avoid years, or even decades, of pain and reduced mobility.

The TOKA treatment process begins with a 3D scan of the affected knee. These scans will be used to design the HTO plate and a 3D printed surgical guide based on each patient’s unique anatomy. The 3D printed guide helps surgeons achieve greater accuracy in a simpler HTO procedure that takes just 30 minutes to complete. 3D printed screw threads in the plates provide optimal position for screws to secure the device to the tibia, or lower frontal leg bone.

Bespoke HTO plates printed with state-of-the-art metal 3D printers offer improved weight-bearing and stability, as well as enhanced comfort, compare with current HTO implants. The in-silico trial demonstrated that TOKA’s medical-grade titanium-alloy plates withstood the stress of weight-bearing movements as well as existing implant technology.

Results of the in-silico trial were published in the journal Nature: Communications MedicineVersus Arthritis, a UK arthritis research and advocacy organization, is sponsoring the first TOKA clinical trial.