3D Printed Casts – Clinical Research
Waterproof, breathable, custom fitted 3D printed casts are the future of healing bone fractures.
A clinical study conducted by Yan-Jun Chen, Hui Lin, XiaodonZhabg, Wenhua Huang, Lin Shi and Defeng Want reports that 100% of the patients studied prefer a 3D printed cast over a conventional plaster cast.
The study, “Application of 3D–printed and patient-specific cast for the treatment of distal radius fractures: initial experience“, published on November 9, 2017 in 3D Printing In Medicine, evaluated 3D printed casts to immobilize fractures in 4 males and 6 females ages 5 years to 78 years old.
Factors evaluated and scored based on patient feedback included stability of immobilization, blood circulation, wear-pressure-related pain, pressure sores, patient comfort, patient compliance, patient preference between 3D–printed cast and conventional plaster cast, cast odor and itchiness.
The casts used in the study consisted of a two-piece, shell-like design held around the patient’s limb with Velcro straps. Each cast included a plurality of ventilation holes and was 3D printed out of polypropylene and poly amide based on scans of the patient’s limbs. In 8 of the patients, the limb opposite the fractured limb was used as swelling in the fracture are prevented acquisition of accurate 3D models.
Casts were fabricated on an EOS P395 laser printer and UnionTech RS4500 stereolithographic printer and the design was patented and assigned to the Chinese University of Hong Kong
This is all ‘well and good’, you might say, but are 3D printed casts readily available or are they still in the research phase?
Well, it’s a little of both. Read on to learn more.
Multiple Solutions – International Inventions
There are actually a number of competing designs in the international 3D printed cast marketplace. They each have slightly different designs but they all share the same patient benefits of being waterproof and breathable.
Jake Evill, a graduate of Victoria University of Wellington with a Major in Media Design and a Minor in Industrial Design, invented the Cortex cast. The Cortex cast is a futuristic looking, 2-piece cast with a unique lattice-like structure printed out of poly amide material. The cast shells are formed around the fracture area and held together by a novel, locking snap fit pin assemblies.
Building upon the Cortex cast, Turkish student Deniz Karasahin invented the Osteoid cast that places ultrasonic transducers within the lattice framework to directly contact the skin. Not possible with conventional plaster casts. Low-intensity pulsed ultrasound (LIPUS) probes, fitted into cast via thin layer of rubber, speeds up bone healing by up to 40%. Karasahin’s design won Gold in the 2014 A’ Design Award & Competition.
Founding partner of MediPrint, a Mexican startup, Zaid Musa Badwan Peralta invented and filed a Mexican patent application for the NovaCast. With hexagon-shaped ventilation openings, the NovaCast looks a bit more ‘industrial’ than the Cortex cast and includes an openable fastening system for removing the cast. Zaid also developed software that eliminates 3D scanning of the fractured limb and automatically generates the geometry of the cast from anthropometric measurements of the patient. At the present time, each NovaCast takes about three and a half hours to print but Zaid is working on cutting that time down to an hour.
Exovite based in Zaragoza, Spain, offers a patented 3D printed immobilization system for humans and a version for animals called the Petsovite. What’s sets Exovite apart is that the cast system is fabricated directly onto the patient’s limb.
Markers placed on area of interest and then scanned to create a 3D model of the splint. Sheets of photo-polymeric material are then placed on area and scanned with UV light to form the cast in place. This method is akin to the traditional plaster cast method and offers more timely immobilization of the fracture.
The company also offers a low frequency electrostimulator that, according to Exovite, shortens the healing process by 3 weeks.
Fathom, a company based out of Oakland CA that specializes in 3D printing and advanced manufacturing solutions, is leveraging social media to put a different spin on the 3D printed cast. They invented the “HashCast”. Using the #CAST mobile app, users review and approve personalized messages for custom printing into the users cast. The #CAST is a demonstration project to show what can be done with the latest technologies and while not yet widely available Fathom will work physicians upon request.
The BOOMcast, powered by an Intel Edison chip, is WiFi-enabled and includes multiple sensors which provide the ability to collect and send real-time medical information to a doctor. With LED lighting and a built-in speaker system, patients can rock out while healing. The speakers can also output a low-frequency sound to speed the bone healing process.
Though the BOOMcast may be a bit over the top and probably not practical or affordable to the general public, it clearly demonstrates what can be accomplished with 3D printing and a bit of ingenuity.
Commercialized 3D Printed Casts
Colorado based ActivArmor is the only known manufacturer to have successfully commercialized 3D cast printing technology in the US. ActivArmor casts can be designed for arms or legs and with partnering clinics in Colorado, Texas, California, Arizona, New York, Missouri and Illinois, it’s only a matter of time before these colorful, customized casts are available nationwide.
Once a doctor prescribes an ActivArmor cast and after swelling of the injured area subsides, the patient undergoes a brief scan and returns in 3-4 days to have their cast installed. The devices are designed to be removable enabling transition from cast to removable splint.
ActivArmor’s business model is designed to serve both the patient and the physician offering scanning equipment and services for free. This service helps clinics manage inventory and staff time to keep costs down which, of course, benefits the patient. Wholesale prices are stated to be below Medicare published rates.
With FDA listing, pending patents, multiple patient testimonials and a growing list of partnering clinics, ActivArmor has a great success story and appears to be leading the pack of 21st century bone healers.
An Alternative To 3D Printed Designs
I ran across this innovative solution while conducting research for this piece. While it’s not technically 3D printed, I could not resist adding this plaster cast-alternative to the post.
Meet Cast21, a company founded by Ashley Moy and Jason Troutner during their senior year at the University of Illinois at Urbana–Champaign.
The FDA listed Cast21 orthodic has all the benefits of a 3D printed cast including breathability and waterproof materials. The cast is applied to the injured area in the form of a soft, tubular, web-like balloon. It is then hardened onto the patient’s limb via a catalyst fluid pumped into the tubular web.
The young startup has a pending patent and is working hard to perfect their design. The technology has been featured in numerous competitions and publications as well as WGN TV.
Associated Patents And Patent Applications
Univ Hong Kong: US9972406 – Modeling Method For Orthopedic Casts
MediPrint: MX2016004601 – 3D Prefabricated Orthosis and Manufacturing Method
Exovite: US10029394 – Methods for Fabricating Immobilization Apparatus:
ActivArmor: US20160074203 – Custom Fitted Apparatus
Cast21: US2018/0153745 – Orthopedic Support Apparatus and Method of Use
Other Related Patents And Patent Applications
SABIC GLOBAL TECHNOLOGIES: WO2018047112 Custom Cast and Methods for Making the Same
MBRACE MEDICAL: US20180049906 A Method for Producing a Brace, the Brace as Such, and a Method to Fix the Position of a Broken Bone in a Limb
ORFIT IND: US20180001547 Immobilisation Element and Additive Manufacturing Method for Making Same
The Future is Now
I am impressed and inspired by the variety of designs, innovative approaches and significant amount of human and financial resources put into the development of these improved methods of healing bone fractures.
I’m sure you will agree that, in time, 3D printed casts will become the new norm and essentially displace outdated plaster cast devices.
I hope this article has inspired you too.
What will you create?