Copy to clipboard 
In December, restor3d announced the successful completion of initial cases using the iTotal Identity 3DP Porous Fully Personalized Total Knee Replacement System, the first fully personalized, cementless total knee replacement offering within the company’s Identity platform. The cementless system leverages restor3d’s TIDAL Technology, a porous architecture that is engineered to achieve optimized osseointegration strength, enhanced fatigue resistance and efficient load distribution. Lauren Ardito, Director of Product Management at restor3D, shared her views on the clinical value the system brings in advancing cutting-edge patient-specific technology.
What was the original design vision behind the Identity Porous Knee?
With the rise of cementless indications due to younger, more active patients getting total knee replacements, the time was right for a cementless patient-specific implant system that’s designed with a baseplate to match patient anatomy and provides optimal bone coverage without sacrificing component rotation, which is critical for solid cementless fixation. Younger patients expect knee implants to last 20 or 30 years before they need another replacement. Removing cement from the equation lowers the risk of potential failure between implant and bone and cementless designs create a solid and durable implant base with a longer lifespan.
How did additive manufacturing factor into the development of Identity Porous?
First, 3D printing patient-specific implants allows for more scalability. On the design side, 3D printing allows us to unlock some unique features. For example, the tibia side of Identity Porous contains peripheral tacks that provide strong initial fixation. And because it’s patient-specific, we optimize the locations of the tacks based on the CT scans of individual patients to ensure we’re creating the most stable implant possible.
In what ways do the implant’s lattice structures and porous architecture impact the system’s overall fixation and load transfer?
Those are important concepts in knee implant design, and our technology is a little different than the typical 3D printed structures found on most total knee systems. Many companies use a printed structure that’s meant to replicate cancellous bone. Instead, TIDAL technology, which was derived from Duke engineering research, is a gyroid lattice structure. Its interconnected porous architecture provides enhanced bone in-growth and fixation with improved pullout strength that is adaptable to various indications.
What were some of the biggest engineering challenges your team had to overcome in terms of ensuring consistency and quality?
The accuracy that’s required during manufacturing presents a unique challenge for patient-specific devices. If you’re producing a high-volume run of off-the-shelf-sized implants, you can reject components that don’t meet quality specifications. You don’t need to inspect every single component individually and can use a standard manufacturing process. When producing a patient-specific implant, every single factor of your manufacturing process needs to be dialed in to match exact specifications. You’re making one implant for one patient, so you need to make sure that your processes are accurate.
restor3D is spearheading a digital-to-implant design workflow. How does that process work and is AI playing a role in it?
Our process starts with a CT scan that gets converted into a 3D model of a patient’s unique anatomy that is then used to design the implant and instrumentation needed for the case. Our team has done a lot of work with AI in terms of improving the timing of the entire process. We use an AI-driven segmentation process of the CT scan and the subsequent manufacturing steps. Looking ahead, we’re trying to push the boundaries of where we can take AI even further. We have a huge pool of patient-specific implants and related CT scans that we’ve amassed over the years. We’re working on a complete AI analysis project that involves assessing how we can extract data from the scans and apply the information to designing the next generation of orthopedic implants.
