I broke my arm when I was thirteen and had to wear a fibreglass cast for ten weeks. I remember trying ever more ingenious ways to scratch an itch that I couldn’t reach with the end of a spoon. Then there was the plastic bag that I taped over my cast before taking a bath, shower or playing on the Slip ‘N Slide.
Anyone who has broken their arm or leg can relate to these challenges, but now a team of engineers hopes to make them a thing of the past.
Chicago-based startup Cast21 has created a lightweight, waterproof and breathable alternative to fibreglass casts that can be worn comfortably while exercising, bathing or even swimming.
The patented design is constructed from a mesh sleeve filled with a resin that’s moulded into the correct position for each patient. The resin then hardens in place and is available in a range of vibrant colours like fibreglass casts. However, unlike traditional casts, you don’t need a cast saw to remove it.
“The majority of fractures happen in children, adolescents and the elderly,” says Cast21’s VP of engineering Veronica Hogg. “Those saws are very loud and all this debris flies off and it’s very messy, it can be extremely frightening. The cast saw also presents a risk of burns to the patient.
“Our product does not require that at all. It’s designed so that a physician can take clinical shears, snip through the tabs and pull it open easily. It was designed to completely eliminate the use of a cast saw and make the healing process far more pleasant for the patient.”
The futuristic-looking sleeve is also faster to apply than traditional casts. Physicians start by measuring the damaged limb using a flexible measuring tape. Once they’ve selected the correct size, they slide the flexible, slightly padded sleeve into place.
The real magic comes from the patented resin; it’s a mixture of two liquids that are mixed together and poured into the empty sleeve through a valved nozzle. It takes about three minutes for the liquid to cure into a malleable gel, at which point the cast can be moulded to fit the patient’s limb before it completely hardens in an additional five to seven minutes.
“Another bonus is that no electricity or water is needed to apply our cast, so it’s very portable.”.
There is reportedly no pain associated with the device’s hardening, and the exothermic heat it produces could even be beneficial.
“It feels soothing. It reaches about the same temperature as a hot tub.”
While Cast21 hopes to make a splash in the field of orthopaedic technology, the innovation is still a work in progress. So far the company only has a forearm model designed in a medium size, but they hope to expand their sizing and create casts for the lower legs in the near future.
“The idea is to prove that this technology works…right now, we are past the prototype stage and have a fully functioning model in place for the forearm. We hope that this technology can span across the entire body. We are looking forward to having a lower limb model for ankle fractures soon.
“We have this radical notion that you can enjoy your healing experience. You don’t need to be restrained from daily activities. I’m from Colorado and I like to go hiking, and the equipment needed to administer our cast is so small and lightweight that hikers and climbers could carry it with them in their backpacks (as a first aid kit).
“It also has potential for use in the military and for at-home first aid. 3D printed casts can be very expensive, and the turnaround time is very slow. Our design is almost instant and very portable.”
Waterproof, 3D-printed casts are already on the market around the US and Europe, but they can cost hundreds, and patients can be left waiting days or weeks for the cast to be printed and delivered to them. There is currently no price point associated with Cast21’s product, but the aim is to make it as accessible as possible.
“We want it to be competitive, and reachable to a large population. We don’t want this to be a luxury product. We are still conducting research in price sensitivity, and the final cost to the patients will be dependent on their insurance and doctor.
“Right now, we can treat what’s known as ‘distal radial fractures’ or DR fractures; that’s a catch-all term for any fracture of the radius that occurs close to the wrist.
“We are hoping, with more data and feedback from physicians, that they would feel comfortable using this technology after a surgery was required. We are interested in expanding the pilot use of our product in clinics. So we would love for anyone interested to reach out to us for more information.”
All photos: Courtesy of Cast21