Key Insights On Conservative Care For Adult Flatfoot

Author(s): 
Patrick DeHeer, DPM, FACFAS, FASPS, and Aaron Warnock, DPM

   A foam box helps to obtain the impressions. We invert the rearfoot as we drive the foot into the foam. Once the heel is all the way down, we then plantarflex the first metatarsal as the forefoot drives into the foam as well. This essentially builds correction into the cast and in theory recreates the patient’s arch to allow the device to combat the strong plantarflexory force of the triceps surae complex at the naviculocuneiform joint complex.

   If we feel the patient will pronate over the top of this device, we utilize a Blake inverted orthotic. The Blake inversion refers to balancing the positive cast more than 10 degrees inverted. This device has a high medial flange. A high medial flange is an increase in the height of the medial side of the device starting just distal to the heel and extending to the distal edge with the apex near the navicular.8 This modification also makes the orthosis slightly wider at the area of the medial arch. We also add a deep heel cup to the device to try to control eversion of the rearfoot. The Blake orthotic can correct a significant amount of deformity. This device is less cumbersome than conventional bracing and lends itself quite well to fitting into a tennis shoe or extra-depth shoe.

   We have the patient utilize a break-in period for all of our custom orthoses. Patients get instructions to wear the devices for 30 minutes to an hour at the time of dispensing and after a seven- to 10-day period, they should have them in their shoes for the entire day. We have them follow up in one month for an orthotic check and instruct them to call the office if they notice any redness, irritation, blistering or an increase in pain.

   An ankle-foot orthosis such as an Arizona AFO (Arizona AFO) may be necessary for severe flatfoot cases. The brace extends proximally to the midshaft of the tibia and distally to the metatarsal heads. One can fabricate the leather upper using a standard Velcro closure, lace-up design or a combination of the two. Once one has ensured proper fitting of the Arizona AFO, he or she can insert the Arizona AFO inside the patient’s shoe for daily wear in keeping with its low-profile appearance.

   As Augustin and Sheldon note, the Arizona AFO functions by decreasing hindfoot valgus alignment, lateral calcaneal displacement and medial ankle collapse.9 During casting of the mold for the brace, the calcaneus reduces to its proper anatomic alignment underneath the tibia and talus. The authors note the brace maintains this relationship via three-point fixation, which is similar in a well-molded cast.

   Some patients may tolerate an articulated ankle-foot orthosis such as a Richie Brace. This brace is effective at controlling foot drop and valgus rotation at the ankle although some patients do not tolerate the brace well. The patient must have complete information about the brace before prescription. It is imperative that the patient is aware that it may not fit well in existing shoe gear. One should only use this type of orthosis to correct the flexible aspect of the deformity. In our experience, a brace cannot correct the rigid components of adult flatfoot. Pain and problems with the skin may increase if the brace provides too much correction in a patient with a rigid deformity.10

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