Current Insights On Bracing For Hindfoot Osteoarthritis
Foot orthoses (FOs) have been a standard treatment in podiatric clinics for decades. Until a decade ago, however, it was rare for American podiatrists to dispense ankle foot orthoses (AFOs) of any kind.
In 1996, the Richie Brace was introduced and it was the first ankle brace to incorporate a custom functional foot orthosis (FFO). Two years later, the Arizona Brace, the first gauntlet AFO to incorporate a polypropylene shell, arrived on the market and was soon widely used within the podiatric profession.
In the last decade, foot orthoses and AFOs of many types have become far more prevalent modalities in the podiatric office as podiatrists have used them for the treatment of pathologies ranging from posterior tibial tendon dysfunction (PTTD) to lateral ankle instability to Charcot arthropathy.
With this in mind, let us take a closer look at the use of orthoses for the treatment of hindfoot osteoarthritis (OA).
What Orthoses Can One Use To Treat Hindfoot Arthridites?
There are many types of FOs and AFOs, and it is easy to become overwhelmed with the many choices involved in prescribing each type. However, when it comes to routine use, podiatrists tend to only use the following five types.
• Functional foot orthoses. There is evidence that balanced custom functional foot orthoses can provide effective symptomatic relief in some patients with subtalar joint OA and, to a lesser extent, those with ankle OA.
• Solid AFO. Solid AFOs are molded of plastic and conform to the posterior leg and foot. They include medial and lateral flanges, and act to limit or eliminate ankle joint motion.
• Podiatric AFO (Richie Brace™). This podiatric AFO is a custom balanced functional foot orthosis attached to medial and lateral uprights. The uprights can be attached via an articulated or fixed pivot (hinge). One would align the pivots with the ankle joint axis to encourage normal ankle joint motion in the articulated model. Both articulated and fixed devices will limit subtalar joint motion while the podiatric AFO with a fixed pivot will also limit ankle joint motion.1
• Gauntlet AFO (Arizona Brace™). Introduced by Ernestro Castro, CPed in 1998, the gauntlet AFO is a custom-made AFO with a plastic shell sandwiched between layers of leather. The device wraps around the circumference of the foot and ankle, and thus provides significant strength with a relatively thin profile. It is designed to stabilize the ankle area and the talocalcaneal, midtarsal and subtalar joints. It provides medial and lateral stability to minimize sinus tarsi impingement, and can reduce forefoot abduction or adduction.2
What The Studies Reveal About Treatment Goals With Lower Extremity OA
The primary goal of bracing in treating osteoarthritis of the hindfoot joints is to limit motion of the involved joint. Literature directly relating to bracing of the arthritic hindfoot is scarce. However, several articles provide direction on how to achieve optimal clinical outcomes.
In a 2006 study, Kitakao, et. al., compared the effects on gait of differing types of custom-made polypropylene orthoses. Researchers evaluated the ankle-foot orthosis, rigid hindfoot orthosis (HFO-R) and the articulated hindfoot orthosis (HFO-A).3 The solid AFO supports the back of the calf down to the base of the toes. The HFO-R starts midcalf and includes the ankle, but not the foot or toes. The HFO-A starts midcalf, has a hinge joint at the ankle and goes to the base of the toes.