By Jordana Bieze Foster

Foot orthotic laboratories have long been the principal players in the computer aided design and computer aided manufacturing (CAD-CAM) of foot orthoses. But practitioners are gradually starting to play a bigger role in the process—a development that dramatically enhances the potential for clinical creativity but also introduces an extra element of uncertainty.

The practitioner’s role in orthotic CAD-CAM, particularly with regard to design, was a central theme of the second annual Orthotics Technology Forum, held in July at the University of Salford in Manchester, UK. In addition to the host university, event sponsors included Delcam Healthcare Solutions, Nora, Walking Mobility Clinics, e-Custom, SSHOES, and The SAVING Project.

Traditionally, the practitioner’s role in the CAD-CAM process starts with a scan of the foot and ends with a prescription; all computerized design and manufacturing is handled by the orthotic lab. But some in the field believe that involving practitioners in the automated design process could result in a better product and also create efficiencies for the laboratory. These advocates include Delcam, which is currently developing CAD software specifically designed so that laboratories can include practitioners in the design process to varying degrees.

“If the practitioner is responsible for the design, the laboratory can make orthotics cheaper and faster. The lab may be able to concentrate on milling efficiencies or add products and services. But ultimately the lab will be able to produce better performing orthotics more cheaply,” said Dan Swatton, healthcare technical product manager for Delcam, during a presentation.

The key question—one that was enthusiastically debated by audience members at the conference—is just how much control over orthotic design a lab should be willing to give practitioners.

“Is it a good idea maybe to allow the practitioner to do eighty percent of the CAD design and then have twenty percent done by the lab?” Swatton asked. “Or might it be even better for the practitioner to do a hundred percent of the CAD so that the lab can just be a milling center or look into new markets for expansion?”

Pros and cons

Attendee concerns included the time and manpower needed for practitioner training, the inability to predict just how committed to the new automated protocol a practitioner might be, and the idea of adding a new channel through which errors could be introduced into the design process.

But attendees representing both the lab and practitioner sides of the equation also acknowledged the potential advantages of such a system.

“If I have a design team of six people and I can make two of those people technical support instead, then I can use those resources in other areas,” said Philip Wells, BSc(Hons)Pod, technical support manager for Salts Techstep, a custom footwear and orthotic manufacturer in Birmingham, UK.

Craig Tanner, BPod(Hons), a podiatrist in the sports science department at Aspetar Orthopaedic and Sports Medicine Hospital in Doha, Qatar, noted that for many practitioners computerized design is a natural extension of conventional orthotic prescription.

“When you write a prescription, you are designing an orthotic,” Tanner said. “I think it makes sense for practitioners to be able to see on the screen what it is they’re prescribing. A lot of times a practitioner will ask the lab for things without really realizing what it is they’re asking for.”

The Qatar experience

Tanner, who also presented at the conference, knows firsthand what it’s like for a practitioner to take responsibility for the CAD-CAM process. In his case, with an ever-increasing patient load and limited access to foot orthotic labs in the Middle East, Tanner has embraced CAD-CAM out of necessity. After several years using a contact digitizer-based orthotic system, Tanner switched last fall to 3D laser scanning, computerized design, and CNC (computer numerical control) machining.

One of the unanticipated challenges of switching to CAD-CAM encountered by Walking Mobility Clinics involved a hallway not much wider than the CNC router intended to be moved through it. Luckily, router and hallway both survived the ordeal. (Photo courtesy of Walking Mobility Clinics.)

There has definitely been a learning curve, Tanner said, but not an insurmountable one.

“I actually find it pretty cool learning about things like machining,” he said. “I guess you can teach an old dog some new tricks.”

In just a few months, the overall time needed to create a pair of orthoses has decreased dramatically (from 104 minutes with the old system to 44 minutes with the new system), though not quite to the level Tanner had expected. Surprisingly, he has found that the amount of time required of the practitioner has not changed significantly, but noted that practitioner time is now used much more efficiently since there is less travel back and forth between the lab and clinic.

Some of that is time Tanner has been using to explore the capabilities of his automated system, particularly those that don’t correspond directly to traditional orthotic protocols.

“The key is that you’ve got two surfaces to work with. Either of those surfaces can be changed, either independently or together,” he said.

One new application he’s developed is a graduated extrinsic post, which is contoured in contrast to the traditional block shape, meaning less material is required. Another innovation involves increasing device stiffness in specific areas with a Y-shaped cross brace, which again allows the orthosis to be significantly thinner overall than it would be using conventional methods.

“We know CAD-CAM orthotics can be manufactured with superior efficiency. Now having experience with it, I can say it may also be superior when it comes to design,” Tanner said.

Tanner is an example of a practitioner who is willing to change his way of thinking about foot orthoses in order to take advantage of what CAD-CAM has to offer. But other practitioners have found that a more conservative approach can also benefit from computerized technology.