Concept to Commercialization in Four Months: How Arbutus Medical Utilized 3D Printing for Rapid Device Development

Arbutus Medical’s TrakPak® launched in 2021. The kit is used to quickly apply skeletal traction to patients who have suffered femur or pelvis fractures, to reduce and stabilize the fractures while they await surgery. The original version of the kit featured a modified Dewalt drill with a sterile cover and an implantable pin. When Postole originally designed this device, he looked for a 3D printer to increase the speed at which he could prototype. Tsao recommended Formlabs’ Form 3. Not only were elements of the TrakPak® prototyped on the 3D printer, but Tsao and Postole were able to quickly 3D print the final designs in sufficient quantities for human factor studies and cadaver testing. Since its release, over 4,000 patients in the US have been treated using TrakPak®.

Human factors testing can be a lengthy process, often due to the time it takes to procure molds and start production. 3D printing meant Postole could quickly provide functional prototypes that could not only be bench and cadaver tested, but looked like the final device as well. The aesthetics were important, removing the noise so that the feedback from surgeons was purely focused on part performance and value.

While the first version of TrakPak® solved one problem for trauma centers, working closely with surgeons and residents illuminated another issue: limited ER access to Kirschner Bow (K-bow) devices, used by orthopedic surgeons to tension the implanted pin and provide a means for applying skeletal traction. Problems include tracking them down and retrieving them, as they’re generally stored near operating rooms but applied in emergency rooms, and finding a device that actually functions, as the pin gripping teeth and tensioning mechanism often wear out. This not only leaves the patient waiting in pain while the K-bow is retrieved, but also wastes the time of emergency room doctors. Arbutus Medical’s response was the QuikBow® pin tensioner. 

Launched in 2023, QuikBow® reduces reliance on Central Sterile Processing (CSP) centers in hospitals, and improves speed and quality of patient care. With the help of Form 3 printers, the printing prowess of Ember Prototypes, and the extensive Formlabs material library, the QuikBow® was designed, developed, tested, and commercialized in one year.

Prototyping the QuikBow®, Postole first looked at machining for parts of the bow, including the arms. “But they're so massive and there's so much coring out, that it was actually prohibitively expensive to get the arms machined for testing, especially for the 30+ design iterations we created. 3D printing with the Formlabs 3D printer was a natural fit.”

As the design developed, Postole reached out to Tsao at Ember Prototypes, because the arms he was prototyping would only fit in Form 3L, Formlabs’ large-format SLA 3D printer. Tsao has extensive experience with 3D printing and the Formlabs material library. He worked with Postole to evaluate the best materials for the QuikBow®. 

For the arms, a rigid material was required. Tsao printed the arms in multiple materials, including Tough 2000 Resin, Rigid 4000 Resin, and Rigid 10K Resin, to help Postole pinpoint the best material for his application. Ultimately, Postole selected Rigid 10K Resin as the best option available. In addition to toughness, the bow needs to tension the pin to over 100 lb and support 40 lb of traction weight. To make the prototypes stronger, Postole iteratively altered the part design to get it to withstand the rigorous testing needed.

While the aesthetic quality of materials was a factor in selecting materials, Tsao manually placed supports and oriented files to ensure minimal post-processing was needed, so that resulting prints were as clean as possible, with a consistent surface finish. 

Postole says, “Phil has done an awesome job of trying to understand the end use of the parts because that's really dictated how he sets them up in PreForm. Which are the aesthetic faces and what are the critical features?” As these prototypes were being sent out for user demos and feedback, they had to look like finished parts. By placing supports in internal areas, Tsao was able to deliver parts that were indistinguishable from injection-molded ones. In addition to specialized setup in PreForm, Tsao developed and 3D printed a jig to hold the parts when washing so they would have a uniform, aesthetically pleasing finish.

During this stage of prototyping, Tsao says, “We basically iterated almost weekly. Every three or four days, Radu would send a new iteration and we'd print it and then send it over to him. It was having a rapid prototyping arm that was not part of your own company, it's just external.” 

A benefit of collaborating with Ember Prototypes was time. With Tsao printing the arms, Postole’s Form 3 was freed up to print other components in-house, enabling him to continue iterating rapidly. All in all, Postole and Tsao did over 30 rounds of prototypes in four months, including some back-to-back, everyday iterations that were shipped to surgeons for feedback the following day.

Part of this process involved analyzing user responses on usability, performance, and perception of value, a key reason the 3D printed prototypes needed to look like finished, injection-molded devices.

QuikBow® was launched in early 2023. Within a few months, Arbutus Medical received feedback that emergency room workers found the QuikBow® was making patient care faster and better. However, it still required the use of a bed frame to pull traction in an upward direction, lifting the device off the patient’s shin. 

Bed frames are clunky apparatuses that require special setup, storage, and tracking, wasting time and resources in hospitals. To solve this pain point, Radu and the design team at Arbutus had a brainwave: they could design some adapters for the QuikBow® with lateral hinge points that lift up the bow so that it clears the patient’s shin. “With this innovation, we basically eliminated the need for conventional bed frames and pulley systems that can take up to two hours to procure throughout the hospital,” says Postole.

The addition of the hinge points came a full three months after commercialization of QuikBow®. says Postole. “We rapidly 3D printed different iterations of this attachment, and sent them to our trusted surgeons. They loved it so much they wanted it right away,” says Postole, “That's where Form 3B came in. We knew that if we picked the right material we could get this new product feature into the hands of surgeons right away.”

For biocompatible parts, Postole wanted a clear resin option to match the other translucent parts in the assembly, and honed in on BioMed Clear Resin and BioMed Durable Resin, ultimately selecting BioMed Durable Resin for its superior impact resistance, noting, “both materials were very strong for our application. Although BioMed Clear passed our initial impact testing BioMed Durable gave us more safety margin for repeated impacts”

Within a couple of months, Arbutus Medical was producing the first clinical units that had been cleared through their quality system.

For most conventional devices, it takes over three months to get molds made and start molding parts. With all the hoops a medical device has to clear to be used in a hospital, Arbutus Medical wanted to be able to implement the improvement immediately, without waiting for molds. This meant another production method was necessary.

Wanting continual feedback on the new bow hinge points while continuing to provide the QuikBow® to surgeons, Postole didn’t want to commit to molds for the bow hinge points, because molds cost $25,000 and cannot be easily changed once they are produced. Postole says, “That's where Form 3B came into use because it was a stopgap for us — we just kept 3D printing them. Eventually, the demand went so high that we couldn't keep up in-house, and that's where Ember stepped in and basically took over all the 3D printing.” 

3D printing enables not just rapid production, but production using the same workflows used during prototyping, for increased efficiency. Plus, by adding print batches or printers, production can easily be scaled as demand increases. 

As demand increased, Arbutus Medical outsourced 3D print production of the hinges to Ember Prototypes, where Tsao would print two batches of parts per day. This stopgap production meant that Arbutus Medical could help improve patient care and start generating revenue from the new product five to six months earlier, while lowering the risk by not having to invest in expensive molds before receiving more clinical feedback.

At first, Arbutus Medical thought they would need 200-500 parts total, but very quickly Tsao was printing about 200 parts a week (14 parts per build, two builds a day), and delivering around 800 parts a month. 3D printing at this level of production involved special considerations, including washing and packing the parts. Tsao designed and 3D printed a custom jig to hold the parts when washing, to ensure the best aesthetic finish. When packing parts, he found that paper or other materials could leave fibers on parts, but bagging them in plastic bags kept them clean. These workflow additions enabled Tsao to deliver parts with the look and feel of injection molded parts, without the costly overhead and while still enabling design refinement.

Tsao has been using Formlabs resin printers since the release of Form 2. Since then, he’s used Form 3, Form 3B for biocompatible printing, and Form 3L for large-format printing.

Up until 2019, Postole had been using FDM printers. “We couldn't get the performance out of FDM printing. The parts weren't solid. We were having nozzles getting clogged constantly. It was just very hands-on and wasting a lot of our time,” said Postole. He asked Tsao for a 3D printer recommendation and, “As soon as he recommended the Form 3 and we got it, we were just blown away by solid parts and being able to just do repeated prints without any issues.” 

Ultimately, Postole says, “being able to 3D print clinical use devices, enabled us to A, get to market fast, and B, quickly validate the value and product market fit.”

Initially, Postole thought Arbutus Medical would 3D print the adaptive hinge points for QuikBow® indefinitely. However, when he realized they were on track to produce on the order of 10,000 per year, Arbutus Medical did a cost analysis and opted to move to injection molding once surgeons confirmed the design did not need to change. For the next device Radu is developing, he’s considering 3D printing for production, weighing material properties, options, and costs.

For Arbutus Medical, 3D printing and injection molding are both important manufacturing methods. With 3D printing, it’s possible to produce looks-like and feels-like prototypes, continue to refine the product in the early stages of commercialization, and do stop-gap production while awaiting molds.

Arbutus Medical and Ember Prototypes continue to work together. The diversity of projects Tsao works on at Ember Prototypes reveals pain points in manufacturing and production, and he’s determined to solve these as he helps his clients, including Arbutus Medical.

Explore resources on 3D printing for medical device development, or talk to a 3D printing expert to learn more about leveraging 3D printers for your prototyping, manufacturing, and production needs.