Rejoint, an ambitious startup orthopedics company based in Bologna, Italy, is combining 3D additive manufacturing (AM), artificial intelligence (AI), and the internet of things (IoT) with a cobalt-chrome platter to give surgeons the first certified 3D printed knee prosthesis made from cobalt-chrome.
The company has been endorsed by the EU Horizon 2020 Small and Medium-Sized Enterprises Innovation and Research Program and received the Fast Track to Innovation award.
Rejoint refers to this high tech solution as a “data-driven mass customization approach to patient-specific implants,” Gian Guido Riva, CEO of Rejoint, told OTW, “There are multiple drivers when it comes to knee replacement: older patients who want to maintain their lifestyle, younger patients who demand a healthy knee, obesity, sports trauma, etc.”
Rejoint’s Points of Differentiation
Rejoint CEO Riva, points out that, while industry has made great strides in terms of kinematic alignment, problems remain with matching implants to patient anatomy and indeed, too many patients are not satisfied with their knee arthroplasty outcomes. “There are complications due to femoral undersizing, femoral overhang, tibial overhang and tibial undersizing, all of which can result in a lifetime of pain and limited functioning for the patient. If there is even a one-millimeter discrepancy then that can cause impingement, bringing on soft tissue pain and impaired mobility.”
Another important point of differentiation for this young company is its Electron Beam Melting method of 3D printing where a metal powder is melted to create a joint arthroplasty implant. “We are the sole company using this process for knee implants. Typically, a system offers 7 to 8 femur sizes and 8 tibia sizes…but there are approximately six million knee replacement patients. This means, theoretically, six million different anatomies to be accommodated with these very few options.”
Incorporating Vitamin E and Silver Coating
Cognizant of the statistic that 10% to 15% of the general population experiences dermatologic symptoms caused by metal hypersensitivity, Rejoint is trying to eliminate that concern through use of non-allergic materials. Gian Guido Riva: “We use non-allergic and ceramic coatings that help prevent any allergic reactions. Additionally, our implants have antioxidant agents, including vitamin E, that are blended into our materials…as well as antimicrobial silver-coated surfaces.”
Rejoint’s Novel Process for Customizing Its Implants
Step one, says Riva, is when the surgeon obtains a CT/MRI scan whose results then flow into the Rejoint data center. “We are then able to use deep computer calculation, i.e., artificial intelligence (AI), to model each implant and manufacture a 3D patient-specific device. Part of the value of the AI is that it compares the patient’s anatomy to several thousand prosthetic dimensions.”
Like a talented “seer,” Rejoint’s solution picks up on correlations from the preoperative period all the way through the rehabilitation phase. “By using internet of things (IoT)-connected wearable devices, we are able to conduct a computerized analysis of intraoperative and postoperative data collection.”
And here’s where Rejoint further distinguishes itself…the information recorded during the surgery is then refined through the use of wearable devices (such as sensor-equipped headbands and socks).
Riva: “We can actually use these wearables to obtain both pre- and postoperative measurements to determine how the patient loads their limb or bends their knee. Our postoperative brace and app connect the surgeon and patient, thus allowing for seamless communication.”
Calling their solution the most fully integrated offering on the market, Riva told OTW, “The patients answer questions about their satisfaction and functioning levels, which results in concrete data with genuine scientific value. The surgeon is able to have real-time feedback, meaning that any issues can be immediately addressed.”
Using Direct Patient Input Data
“Although the largest orthopedic companies make products for millions of patients, they have little hard data on patient satisfaction. Surgeons and hospitals can translate data through clinical studies, but they don’t have direct patient input regarding satisfaction. Our solution treats patients with a truly personalized technology that connects them with their surgeon throughout the entire episode of care.”
The Goal Is a Perfect Fit
For patients, surgeons and hospitals alike, says Riva, there are superb benefits to Rejoint’s high-end integrated system. The company hopes to deliver products that deliver a better fit that significantly reduce kinematic conflicts, tendon impingement, and discomfort due to soft tissue contact with bone. Says Riva, “With our product, there is a lower risk of infection, vastly decreased risk of allergic reaction, less blood loss, and an integrated trabecular structure for improved osseointegration.”
On the surgeon side, there is computer-assisted preoperative planning, computerized surgical guidance and a shorter procedure because the surgeon doesn’t have to try multiple configurations. One satisfied surgeon told OTW, “The last patient I treated with the Rejoint solution was the best of my entire career.”
Riva added, “Physicians know that dissatisfied patients won’t return for surgery on the other knee…they also know that they will tell their friends about their experience. With Rejoint, patients’ results are optimized and they will feel comfortable returning for the other knee if necessary.”
As for hospitals, they see short- and long-term benefits, says Riva. “From faster bed turnaround to being able to market an appealing and unique service to attract patients, Rejoint is ideal for hospitals looking for a way to stand out from the crowd. Five years from now, patients will choose hospitals based on references…we will probably see a ‘Trip Advisor’ for knees emerge…and we want to have the top ranking.”
And pricing?
Rejoint, which is in the process of obtaining FDA 510(k) clearance, aims to price its system so that it is widely affordable. “At the present time,” states Riva, “the technology is on the expensive side. However, we are collaborating with GE Additive to bring down powder-based production costs by reducing cycle times and optimizing parameters.”
But the last word in patient satisfaction must be left to the patient…one told OTW: “I want to thank the entire Rejoint team for the support I received throughout my ‘patient journey’—from the first visit to the end of my rehabilitation. I feel like I have the same knee as when I was 25 years old!
LETTER TO THE EDITOR:
Dear Robin,
I, like so many orthopaedic surgeons, am addicted to your “Orthopedics This Week” publication. You have done an excellent job raising this to a high level of immediate news yet intelligent reporting.
I feel I should however, protest a report in the Volume 16, Issue 26, August 18, 2020 publication in which, on page 24, you allow a designing surgeon, without comment, to state that “patients achieve painless joint replacement for life due to full congruence in every dimension.”
This is obviously ridiculous and for something which uses three new technologies and has a very short history already, it is incredible. I feel this merits correction and that your editors need to be more circumspect in fostering concepts such as this, particularly since the success of your work gives articles published within it a credibility that they may not deserve. I believe that is the case in this situation.
My best personal regards as always.
Very truly yours,
Robert E. Booth, Jr., MD
Total Knee Replacement and Revision
Medical Director
Jefferson Health / 3B Orthopaedics
(Original letter on file-Orthopedics This Week)