3D-Printed Hand Orthoses for 98% of clinicians.

blank blank Nov 03, 2022

Introduction:

3D-printed hand orthoses fabrication is currently rare in hand therapy clinics. As outlined below, there are compelling reasons for therapy providers to consider 3D-printed hand orthoses over traditional methods of fabrication. 

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PLA resin (left) vs. PLA filament (right). Resin gives a better surface finish whereas filament prints demonstrate better measures of strength. 

Personal Clinical Experience: 

My personal experience with performing hand therapy and orthosis fabrication started with an abrupt phone call three years ago. Our island had been without a full-time hand surgeon for ten-plus years and suddenly we had a new hand surgeon practicing. 

This particular surgeon called me one day and said: “Your clinic is the only clinic that takes all Medicaid plans, I need you to start seeing my hand patients ASAP even if you have no experience with treating hands”. Calls like this are commonplace in rural areas all over the world. In rural areas everyone spreads themselves thin, trying to fill in as many service gaps as possible.  

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Elegoo Saturn (left) and Ultimaker S5 (right). Both machines have made in excess of 150 orthoses for post-operative patients. 

Quickly, I began to learn as much as I could about hand-forming thermoplastic splints. Hand-forming splints manually is probably more art than science and takes years to train one’s eye to guesstimate template drawings that are later transferred onto flat thermoplastic material. 

Soon I realized that my own availability as a clinician was not enough to adequately cover the tremendous number of post surgical hand patients that needed custom orthoses. Like all rural areas, rural Hawaii has a high turnover rate in healthcare personnel. Sending providers to formal orthosis training didn’t solve the problem of having enough trained staff to see hand speciality cases due to the fast turnover rate.

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Printed in PLA resin. This print matches the patient’s proximal palmar crease perfectly which is important for allowing as many digits movement as possible and preventing tendon adhesions. 

What I needed was a way to centralize the process of orthosis creation in a way that any provider, from anywhere, without hand experience could quickly create and give their patients a perfect orthosis. Generally, it takes me under five minutes to teach a new physical therapist how to properly 3D scan patients. From there, the new therapist can avoid worrying about creating an orthosis themselves. The scan is sent to one of our engineers and then I print and post-process the device in my own garage. Sometimes I will even start printing remotely when I am away from home.

Best of all, we now have a solution for patients living on Hawaii’s extremely remote islands who aren’t able to travel. We have taught rural physicians how to perform 3D scans and then we print and mail the orthoses to the patients. 

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Printed in PLA filament and heat smoothed with a mini blowtorch for a patient with an ulnar neuropathy to prevent further contractures from forming.  

For scanning purposes, our current working solutions include: Paring an iPad mini with the Structure Mark II pro scanner and using either the native Structure app for scanning and export or using Spenty’s app which includes an embedded scan-to-export feature. We have also been able to achieve accurate scans from the EM3D app which uses the front-facing cameras on LIDAR capable iPhones to generate a scan. For $6.99 the app allows users to export scans in a variety of formats including common formats such as OBJ and STL. 

As for printing orthoses, our clinic currently uses both FDM and DLP printers. For prints where strength is the dominant concern, I use the Ultimaker S5 using Ultimaker’s PLA filament. PLA is the filament of choice due to both heat and vapor smoothing capabilities. Post-processing with heat and vapors has eliminated the need for both sanding and tumbling which allows me to get prints to patients within a 24-36 hour time frame. PLA also heat molds at lower temperatures vs. other traditional filaments which makes spot adjustments simple within the clinical setting. 

DLP printing consistently produces higher-quality surface finishes compared to FDM and patients overwhelmingly prefer the feel of DLP prints over FDM. I am currently using the Elegoo Jupiter with Sirayatech blu and fast resins. These resins and incredibly quickly to a flush surface with vibrating multi tools when removing supports. DLP resins do crack much easier than FDM and generally, I avoid DLP orthoses with active patients who plan to stay involved with sports while healing from common wrist fractures. 

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All orthoses are printed with light supports at 60% density. Prior to printing, the FEP film is sprayed with RainX to allow each print layer to come off the FEP easily. 

Conclusion:

My personal opinion is that the 7,000 Certified Hand Therapists will not soon adopt 3D printing and leave behind thermoforming. However, for the 293,000 physical and occupational therapists that are not Certified Hand Therapists, 3D printing is an easy-to-introduce solution that will allow generalists to provide specialty-esque care with significantly fewer training requirements than thermoforming manually. Enabling generalists to provide orthosis fabrication would create significant benefits for underserved patients throughout the world.  

About the Author:

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Brett Carey is a graduate of Old Dominion’s 2010, Doctor of Physical Therapy school. His career began with co-founding the start-up IREHAB.com which became the 43rd most downloaded fitness app – out of 7,000 fitness apps in 2013.

Brett has had extensive non-profit involvement and has served as the Board President of several non-profits including the West Hawaii Community Health Centers, Project Expedite Justice and We Make Hawaii.

In 2019, was appointed as an ambassador to Belfast, Northern Ireland, and has ongoing roles in both peacekeeping and business development.

Brett currently serves as the Key Opinion Leader for Desktop Metal’s Rehabilitative technology division. MIT has named Desktop Metal as one of the world’s 50 smartest publicly traded companies.  He also is the CEO of Kalo Physical Therapy – a multi-specialty outpatient clinic in Kailua Kona. 

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