3D-printed casts look great, but do they provide any substantial benefits to patients?

Have you ever wondered why the cast hasn’t changed in (what seems like) forever?

Sure, it’s great to have bright colors, but that’s not really a fundamental change; it’s certainly not a change or improvement in the technology.

But recently, with the advent of 3D-printing technology, designers are beginning to think about printing patients’ hearts before surgery, livers, prosthetic hands, and now casts.

Deniz Karashin, a Turkish industrial designer, has specifically focused on a 3D-printed cast that enables portable low-intensity ultrasound systems to attach to it.

Not only are the aesthetics of Karashin’s cast much better than the traditional plaster cast, but it’s also breathable, washable, removable via a locking system, and a little less prominent.

This new cast also claims that hooking up a low-intensity ultrasound to it for twenty minutes a day will decrease injury time by 38%.

But is this a technology that will take off? Do we want more discrete casts?  Can it truly better the patient experience beyond mere comfort?

Dr. Brian Foster, an upper-extremity (hand, elbow) orthopedic specialist, weighed in on the new technology.

Daniel: Why haven’t we seen changes in the cast?

Brian Foster, MD: It is important to consider the main purpose of any product.  A cast is for immobilization and fracture healing, and there haven’t been any changes recently because “if it ain’t broke, don’t fix it.”  Fiberglass/plaster casts have been working well for decades.

The first thing that comes to my mind with this new concept is that it is probably a little cost prohibitive.  Plaster and fiberglass are inexpensive materials, but 3D printing would require different materials, scanning equipment, personnel, and of course the equipment.  Right now, we have all-star cast technicians, who do a great job with less expensive materials.

That technology has been working, so we haven’t changed it.

For many acute fractures, the first line of treatment is either a surgery or a cast, and then down the road, we can use an ultrasound bone stimulator for delayed healing or no healing.

Daniel: Do you think this is an example that’s cool, comfortable, and exciting, but it may not pan out?

Brian Foster, MD: The idea is interesting in the sense that you have a strong outer customized shell that can easily incorporate ultrasound to potentially increase bone healing.  But often casts are used to protect an extremity, and when people have the ability to take this shell on and off, we may lose that ability to protect the extremity, because we can’t guarantee that the shell is being worn at all times.

We often resort to a removable splint after we’re finished with the cast.  Also, casts stand out, and that can be a good thing.  Casts can easily be seen by other people, letting them know that patients are injured so that they can be more careful around them, hopefully reducing the chance of further damage to the affected extremity.

Daniel: In your niche of orthopedics, is there something that you wish were 3D-printed that’s currently not?

Brian Foster, MD: We often use CT scans for advanced imaging of fractures and joints.  For pre-operative planning, it can be helpful to use 3D technology for CT reconstructions, which give us an overall 3D picture of a fracture and joint; however, we also utilize the other more standard images of the CT scan.  In that setting, 3D technology is more of a supplemental option rather than a fundamental technology.

So 3D imaging is helpful, but not always necessary.  Someone may come up with an application of 3D technology that will change my practice, but it hasn’t happened yet.