At the 2005 co-located meetings of the American Academy of Orthotists & Prosthetists and the Association of Children's Prosthetic-Orthotic Clinics (ACPOC), Ammanath Peethambaran, CO, University of Michigan, and Mark Taylor, CPO, University of Michigan, described the development of a therapeutic AFO powered by artificial pneumatic muscles. The lightweight carbon-fiber orthosis, which provides mechanical assistance during locomotor training, is powered by two artificial pneumatic muscles that supply dorsiflexor and plantarflexor torques.
The design is used exclusively to train patients with spinal cord injuries. They relearn how to walk through repetition of the motions. As the patient's strength improves, as confirmed by EMG measurement, the AFO can be regulated and the power can be reduced accordingly.
Previously such patients have been physically trained in a time-consuming and labor-intensive process that requires the participation of three physical therapists working together.
"Now one very low-cost pneumatic-muscled AFO replaces three physical therapistsa clear cost and efficiency advantage," says Peethambaran.
CAD/CAM Evolves
CAD/CAM, with its broad range of new orthotic applications, also continues to be a value not fully appreciated by many. Peethambaran notes that a majority of the orthotists in the US are still using traditional plaster-cast methods for cranial remodeling, while only a small percentage are availing themselves of the advantages of an electronic system.
"Computer-assisted technology is not at all difficult to use; at this point the greater problem is affordability," he says. "It will be many years before the systems are widely available and affordable."
Although the use of CAD/CAM for spinal systems is greater, says Peethambaran, there is still a long way to go in this area, as well.
Don Katz, CO, LO, FAAOP, Texas Scottish Rite Hospital, Dallas, reports that although Scottish Rite fabricates orthoses in its own lab, it is still advantageous in some cases to take measurements which the manufacturer uses to produce a custom orthosis or module, utilizing CAD/CAM technology
"It can be a timesaver," says Katz, citing the new Charleston Brace as an example. Previous custom spinal orthoses required the creation of a bivalve plaster cast in two stages, like the top and bottom portions of a turtle shella process which took two or three people to accomplish efficiently. "Today, it is a matter of simply taking a standing cast, which can easily be done by just one person, who wraps the patient with a roll of fiberglass that remains rigid, capturing the patient's shape," Katz explains. By partnering that standing cast with an X-ray, Charleston can use CAD/CAM to manufacture a custom-bending orthosis, using measurements taken from the standing cast. That results in reduced casting time for the patient, and the orthotist can cast the patient without additional assistance.
Hanger Prosthetic & Orthotic Inc.'s new Insignia orthotic CAD system offers advantages of its own.
Kaia Halvorson, CPO, Hanger's vice president of orthotics, reports that during the last year the program has been introduced through a carefully segmented release process. The Insignia system provides complete spinal, cranial, and custom knee measurement capabilities. "It's been well-structured; each time there is a release, all procedures and protocols are in place to assure appropriate outcomes," says Halvorson.
Insignia introduced AFO capabilities in late 2004 and is currently adding KAFO capabilities.
"One of the nice things about Insignia," says Halvorson, "is
that we can create an actual patient model from our scans, rather
than relying on a library of templates. Another of its great
benefits is that now we have objective data to support all of our
clinical documentation. Before, we only had subjective data. By
creating an exact patient model and being able to compare that
model throughout the progression of treatment, we have the ability
to go through and segmentally look at objective data. Now we can
validate clinical claims and create effective letters of medical
necessity to help gain reimbursement for patients who may have been
denied in the past."
