Tag Archives: cast

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Fracture Care Of The Future: Traditional Casts vs 3D-Printed Braces

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I’ve been fascinated by 3D printing for at least a decade.  Here are some examples from previous posts:

Unfortunately, practical applications have been relatively limited in the field of trauma.  But a lot has been going on in the background. The trauma research group at Erasmus Medical Center in Rotterdam recently published a systematic review on very practical work using 3D printing to produce casts and splints.

Sounds like a very mundane problem to through high tech at, right? But for those of you who look after patients with fractures that have been casted, you know the problems that can arise. Casts can be too tight. They can be ill-fitting. The patient may have soft tissue injuries that require windows cut into the side of the cast. Additional technology such as electrical stimulators may be indicated to enhance healing.

The old-fashioned way of creating a plaster or fiberglass cast seems crude. It is shaped by hand using skill and a fair amount of guesswork. If it’s just a bit too tight, serious complications may occur. If windows are not cut properly, it can destabilize the entire cast.

The Rotterdam trauma research group performed a systematic review of 12 papers that have been published on the topic of 3D-printed casts used in the treatment of forearm fractures. The authors found that most currently use a technique called fused deposition modeling with a polylactic acid substrate.

Instead of relying on subjective skill and luck to shape the brace, the uninjured forearm is scanned with a 3D scanner. The data is fed to a computer aided design (CAD) workstation and a mirror image is created and further refined. Special features such as soft tissue windows or entry points for bone stimulators can be designed into the brace at that time. Because the strength of polycarbonate exceeds that of plaster and fiberglass, it is possible to create a design with a great deal of open area so the underlying skin can be monitored. And allowances can be made for areas with swelling not present on the control extremity.

The data is then fed to a 3D printer to actually create the cast. Here’s an example:

This design is stronger that a traditional cast, is cool and comfortable, and avoids problems with hidden tissue injury or unrecognized foreign objects dropping into the cast creating major problems.

The use of 3D-printed casts and braces is relatively new and is used in only a few centers. For this reason, we do not have enough numbers to show that it is equivalent to traditional casting. Yet. But as the price continues to drop and use becomes more widespread, it’s only a matter of time before you start seeing these items in your own trauma center.

Reference: Personalize d 3D-printed forearm braces as an alternative for a traditional plaster cast or splint; A systematic review. Injury, in press, July 29, 2022. https://doi.org/10.1016/j.injury.2022.07.020

General

New Technology: 3-D Printed Casts For Fractures

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I’ve written quite a lot about the promise of medical applications for 3-D printers. Here’s another one for use by trauma professionals.

Look at the good, old-fashioned plaster cast. It’s been around for decades, and serves its purpose well. It’s easy to apply, inexpensive, and reasonably durable.

Then, along came fiberglass. It’s lighter, more durable, and a bit more water-resistant. And not a whole lot more expensive.

But both of these items have drawbacks. They are heavy. It’s best not to get them wet. Their application is very operator dependent. And probably most importantly, they are opaque. This masks any wounds or skin conditions under it for an extended period of time.

Deniz Karasahin, a Turkish student, won a design award for the development of a 3-D printed cast. It used the appearance of cancellous bone as a model, and is aesthetically very cool. A body scanner is used to scan the affected extremity so that the cast can be customized to the patient. The actual cast is printed from plastic, and can be rendered in a variety of colors. It is hinged, and locks together with a simple pin mechanism.

Bottom line: This is an interesting development in 3-D printing. However, it is not for everybody. Cheap plaster and fiberglass casts are very suitable for many patients. But for some, having the ability to inspect the underlying skin or deal with wounds will make this item much more desirable. And keep in mind, this product was developed for aesthetics. The holes can be much larger and still maintain strength and rigidity. So the cast of the future could be mostly holes, making it very light and shower compatible. Many people might be willing to pay a little more for this convenience.

Note: Ignore the LIPUS ultrasound units that can be incorporated into the one in the article. This is still unproven technology and I don’t recommend it.

Reference / photo credit: A’Design Award Competition