Expert Insights For Prescribing AFOs

These knowledgeable panelists discuss when to prescribe custom-hinged ankle-foot orthoses (AFOs), non-hinged AFOs and custom gauntlet AFOs, and also describe common shoe modifications for the devices.

Q:

For what conditions do you prescribe a custom-hinged AFO?

A:

Bruce Williams, DPM, and Patrick DeHeer, DPM, FACFAS, will use custom-hinged AFOs for patients with posterior tibial tendon dysfunction, chronic ankle arthritis or hindfoot arthritis.

Dr. Williams will also use hinged AFOs for peroneal tendinitis, chronic midfoot injuries or for post-stroke patients. He uses a hinged AFO whenever he wants to preserve ankle joint range of motion (ROM) and when the AFO will not exacerbate the primary issue he is treating.

Additionally, Dr. DeHeer will use hinged AFOs for drop foot, Charcot deformity and chronic ankle instability.  

When it comes to podopediatrics, Russell Volpe, DPM, will use a custom-hinged AFO for patients when he wants to encourage ankle dorsiflexion while still maintaining AFO-level control of the foot and lower leg. For example, he might use a custom-hinged AFO for a patient with spastic diplegic cerebral palsy who has significant enough involvement to benefit from AFO-level control and ankle dorsiflexion is adequate (either as a condition of the diplegia or post tendon-lengthening). Dr. Volpe says a hinged device is particularly useful for such patients as it can help preserve/encourage the added range of ankle motion provided by the tendon lengthening. Dr. DeHeer will use custom-hinged devices for those with lower extremity weakness due to neuromuscular disorders.

Dr. Volpe might also choose a custom-hinged AFO for low-muscle tone patients who need AFO-level control but in whom he wants to preserve ankle dorsiflexion in stance. For these patients, he is likely to use a plantarflexion stop to prevent the low-tone child from going into a hyperextended knee position through excessive ankle plantarflexion.

Another patient in whom Dr. Volpe might use a custom-hinged AFO would be a toe walker, provided he can get the ankle to at least 90 degrees (with more being better) on the clinical exam. As he notes, this will keep the child plantigrade and encourage ankle dorsiflexion if the child has the range of motion available.

Dr. DeHeer has always decided on which type of brace to use based on whether the deformity is correctable or not. If he can get the foot into a neutral position, he will use a Richie-style brace. Otherwise, Dr. DeHeer will use an Arizona-style brace.

Dr. DeHeer also cites the TayCo External Ankle Brace (TayCo Brace), a cast boot type of brace that attaches to a shoe.

“I have found this to be very helpful in certain cases both surgical (in the post-op course when transitioning into a shoe after an ankle or hindfoot procedure) and non-surgical (like a severe ankle injury and the patient needs to wear a shoe to return to work),” notes Dr. DeHeer.

Q:

What types of non-hinged AFOs do you most frequently prescribe and for which conditions?  

A:

Gene Mirkin, DPM, says the Arizona brace is “by far” his most commonly prescribed non-hinged AFO. He notes the Arizona brace provides “phenomenal stability” for unstable biomechanical conditions, whether they involve soft tissue, bone or both. He most commonly uses this brace for the arthritic foot that can’t tolerate motion. Likewise, Dr. Williams will use an Arizona brace for those with ankle arthritis.

“(The Arizona brace) is a great ‘go-to’ brace for patients with chronic posterior tibial tendon dysfunction or peroneal tendinitis/interstitial tears who are not good surgical risks,” maintains Dr. Mirkin. “Patient acceptance is much better with this type of bracing because it can be used in a bigger variety of shoes than some of the bulkier counterpart braces.”

For pediatric patients, Dr. Volpe uses solid custom AFOs for low-tone patients who need higher control and do not have ankle dorsiflexion. He adds these devices may also be beneficial for patients whose muscle tone is so low or when the foot is so flaccid that the child will collapse into a dorsiflexed ankle position in a hinged device but can maintain 90 degrees of dorsiflexion in a solid AFO.

Dr. DeHeer uses a non-hinged AFO when the foot/ankle requires healing at 90 degrees (one example would involve drop foot when not using a dorsi-assist hinge) or there is gross instability (Charcot ankle/hindfoot deformity).

Dr. Volpe says non-hinged AFOs may also have a role for patients with drop foot but only if he does not want the ankle to dorsiflex. If the goal is to maintain swing clearance and allow ankle dorsiflexion, Dr. Volpe will more likely choose a hinged AFO with a plantarflexion stop, which can accomplish both goals. He notes clinicians can apply this same principle to adult drop foot cases as well.

Q:

When do you prescribe a custom gauntlet AFO?

A:

Dr. DeHeer uses a custom gauntlet when the foot is rigidly deformed and he cannot reduce the deformity clinically. He notes examples of this would be stage 3 or 4 posterior tibial tendon dysfunction, or a mild Charcot deformity that does not require a Charcot restraint orthotic walker (CROW) boot and can still fit into a shoe.

Dr. Williams uses custom gauntlet AFOs for patients with degenerative joint disease of the ankle. He will sometimes use the devices for patients with posterior tibial tendon dysfunction who do not like the look of a hinged AFO device and prefer the look of a gauntlet brace. Dr. Williams says gauntlet braces work best in those who need limited ankle joint ROM.

Dr. Mirkin is ambivalent about using custom gauntlet AFOs for chronic posterior tibial tendon dysfunction and peroneal tendon disorders. As he notes, patients are able to hide the devices underneath pants and use them in most shoes, reducing the risk of patients not being adherent with necessary bracing due to style issues. Dr. Mirkin uses custom gauntlets frequently for patients who are not good surgical candidates. He will use custom gauntlet AFOs to enhance stability for elderly patients.

Dr. Volpe does not often use custom gauntlet AFOs in children as he sees little indication for the devices in that patient population. He will use custom gauntlets occasionally in adult patients with severe rearfoot and midfoot deformities that require a level of support and control not available with an AFO. For example, he will use custom gauntlets for post-traumatic patients, those with Charcot feet, patients with postoperative complications and the like.

“My experience with gauntlet AFOs is that casting and fabrication are very exacting and intricate, and unless you get the casting and the fit exactly right, patients have difficulty tolerating/using them,” says Dr. Volpe. “I often find that someone who needs a gauntlet AFO is best sent to someone who does a lot of them and who can make a lot of adjustments and modifications as needed.”

Q:

What shoe modifications do you most frequently prescribe for use with an AFO?

A:

Dr. Volpe most commonly uses a shoe/sneaker that is big enough to accommodate the size and bulk of the AFO device. He says roomy, deep counter (often high top) sneakers with a high, wide toe box are best and notes there are options for this type of sneaker for the pediatric population. Dr. Volpe adds that removable insoles always help in providing additional room for the device once they are removed from the shoe.

As Dr. Mirkin emphasizes, the biggest shoe modification physicians need to make with the use of an AFO is the style and shape of the shoe that patients can wear with an AFO. He often does not find shoe modifications necessary but says his most common addition would be a rocker sole to help limit dorsiflexion for the arthritic patient. Dr. Mirkin occasionally uses a heel lift if the patient has had some post-surgical limb length discrepancy, whether it is acquired or congenital.

As for shoe modifications, Dr. Volpe will most likely prescribe medial or lateral buttresses to extend the lever arm of the shoe in one direction or the other to reduce pronatory or supinatory deformities acting on the foot and ankle, which he notes the device itself may not adequately control. Sometimes he says one can accomplish this effect just by having a good out-flare to the midsole of the shoe, which can obviate the need for an additional buttress.

In cases of limited first metatarsophalangeal joint (MPJ) or other MPJ dorsiflexion, Dr. Volpe may also prescribe or add a rocker bar to a shoe to help the foot and ankle with the AFO propel adequately over the forefoot.

Dr. Williams will use lateral flares for those who are post-stroke with a supinated foot position. He uses rocker modifications in those with ankle degenerative joint disease.

Dr. DeHeer does not use a lot of modifications with AFOs and usually only uses a fixed hinge modification when it is required. He says he keeps the order for all three types of AFOs pretty standard.

Dr. DeHeer is a Fellow of the American College of Foot and Ankle Surgeons, and a Diplomate of the American Board of Podiatric Surgery. He is also a team podiatrist for the Indiana Pacers and the Indiana Fever. Dr. DeHeer is in private practice with various offices in Indianapolis and is the founder of Step by Step Haiti.

Dr. Mirkin is board-certified in foot surgery by the American Board of Podiatric Surgery and in podiatric medicine by the American Board of Podiatric Medicine. He is a Fellow of the American Society of Podiatric Surgeons and the President of Foot and Ankle Specialists of the Mid-Atlantic, LLC, a Division of US Foot and Ankle Specialists.

Dr. Volpe is a Professor in the Department of Orthopedics and Pediatrics at the New York College of Podiatric Medicine in New York City. He is in private practice in New York City and Farmingdale, N.Y.

Dr. Williams is the Director of Gait Analysis Studies at the Weil Foot and Ankle Institute. He is a Past President and Fellow of the American Academy of Podiatric Sports Medicine. Dr. Williams is the Past President and Fellow of the American Academy of Podiatric Sports Medicine. He is the Director of Breakthrough Sports Performance, LLC in Chicago.

For further reading, see “Key Insights On Orthotics, AFOs And Casting For Kids” in the June 2017 issue of Podiatry Today. To access the archives, visit www.podiatrytoday.com.