The company has partnered an Arcam EBM Q10plus system with artificial intelligence (AI) to produce customised parts, such as tibial plates and femoral condyles, for replacement knee surgeries.
Typically, the knee arthroplasty market relies on standard prosthetics, offered in a limited range of sizes. Oversized and or undersized implants are likely to not only cause discomfort with the patient constantly aware of the presence of an artificial joint, but also lead to muscle and ligament decay.
By integrating additive manufacturing, however, Rejoint is able to model implants based on the patient’s CT scan, before AI algorithms analyse the imagery and identify the most suitable size for each specific case. AI compares the patient anatomy with several thousand prosthetic dimensions, helping to provide the surgeon with the optimal configuration for positioning the prosthetic components and simulating the operation, and forming the basis for production of the prosthesis and patient-specific tools for surgical planning.
“Having all this data made us realise that we could link it to the information recorded during the operation and, in turn, this data could still be further improved upon if we could collect through the use of wearable devices, such as sensorised headbands and socks, both pre- and post-operative measurements, on how the patient loads their limb or bends their knee, until post-operative evaluation questionnaires have been completed,” commented Gian Guido Riva, CEO of Rejoint. “By 2022, we will have the complete data of thousands of cases available. This will provide us with an unparalleled wealth of application information, in terms of completeness, in the sector. Despite the sale of millions of pieces, there is little or no information on what happens post-sale.”
The first implant to have been carried out is reported to have achieved a high degree of patient satisfaction, according to Professor Maurilio Marcacci, Head of the Joint Kneee Reconstruction Centre at Humanitas Research Hospital in Milan, who performed the surgery. Rejoint has since applied for FDA 510(k) clearance, with that process ongoing, and is working with GE Additive to reduce powder-based production costs.
GE Additive’s Arcam EBM Q10plus machine was selected by Rejoint to produce its knee implants after much deliberation, but the company is happy with its choice, outlining the quality of its output and GE’s wealth of industrial experience as key benefits.
“When it came to additive manufacturing, we were initially undecided about the most suitable solution for personalised cobalt-chrome prosthetics and were valuating DMLD and EBM,” said Riva. “Both modalities offer a good level of resolution and quality, but we ultimately opted for the GE Additive Arcam EBM Q10plus system. The knowledge and industrialisation support that GE was able to provide us and the professional experience of their local tam here in Italy also informed our decision. At the moment, ours is still the only solution for additively manufactured knee prostheses in cobalt-chrome to be certified and introduced to the market.”