While the first iteration of the Formus software has focused on the hip and shoulder joints, Formus Labs is also now actively working in the knee space. This recent case study, successfully completed alongside Dr. Paul Monk and the Auckland Bioengineering Institute (ABI), showcases the versatility and effectiveness of the Formus platform.
This case study centered around a high tibial osteotomy (HTO), a procedure whereby the knee joint is realigned through the cutting and insertion of a wedge to relieve pressure on the affected joint. This procedure is primarily used in cases of early-onset arthritis, as a preventative measure or an alternative to a full knee replacement.
This particular collaboration with Dr. Monk, who also heads up our clinical advisory board, and the ABI began in August 2019 with funding from Callaghan Innovation. The process began with the patient’s MRI and X-rays being used to create a patient-specific model of their lower leg. In silico surgical planning was then performed. A calculation of the optimal angle for the HTO wedge is facilitated using the computational modeling component of the Formus platform and produced as a 3D-printed wedge unique to the patient.
This wedge was used in surgery by Dr. Monk during the HTO, to effectively redistribute pressure across the patient’s knee joint, with remarkable results. After only two weeks the patient was back on their feet (when six weeks of crutches are standard for this procedure), and continues to be in excellent condition.
“HTO is an effective procedure with a 30-year history, but until now we have suffered from rudimentary planning tools and inaccurate intra-operative measurements. The Formus platform has revolutionized our approach to this operation. It allows for accurate assessment of the effect of subtle changes in the desired wedge opening before we go into the OR, which we haven’t been able to do previously. Once we are happy with the final correction and their predicted weight distribution during gait, we can 3D print the wedge to take into the OR. This provides us with so much more control over providing the desired correction.”
Formal clinical evaluations of the Formus platform are now officially underway, with plans to expand the use of the software across other joints and procedures. Results like this serve to move us closer to our stated goal of helping orthopedic surgeons create better outcomes for patients undergoing all joint replacement surgeries worldwide.