Exploring The Role Of Orthoses For Flatfoot Conditions And Equinus

Author(s): 
Guest Clinical Editor: Joseph D'Amico, DPM

   If Dr. Volpe determines that the asymptomatic pediatric flatfoot is “abnormal” for a child of a certain age, he treats the condition. Although he notes a number of ways to define “abnormal” in this context, Dr. Volpe considers the degree of compensation on weightbearing, family history, structural comorbidities leading to pedal compensation and the limitation or modification of activity.

    “I feel very strongly that to wait for a pediatric flatfoot that is abnormal to develop symptoms before treating it is missing a golden opportunity to place a child’s foot in a neutral position, improve function and reduce the likelihood of the child developing symptoms,” says Dr. Volpe. “There is absolutely a preventative medicine aspect to this.”

   Dr. Valmassy often sees asymptomatic pediatric flatfoot via frequent referrals from pediatricians. His initial evaluation includes determining the extent of the pathology from a biomechanical perspective. He has developed a formula wherein if the child initially stands in an everted position of 7 to 8 degrees, then by the age of 7 to 8, the heel will hopefully develop into a perpendicular attitude. Utilizing these numbers, Dr. Valmassy says the child loses approximately 1 degree of calcaneal eversion per year up to age 7 or 8.

   Therefore, if Dr. Valmassy sees a 5-year-old child with a flatfoot and the foot is 5 to 10 degrees everted, he considers the child’s foot to be markedly abnormal. In this case, Dr. Valmassy says the child will most likely not outgrow the condition or develop a normal foot over the next two to three years. For such a child, he will employ a functional foot orthosis to attempt to protect the developing foot and the more proximal structures. For children up to age 3 or 4, he will typically utilize a Kiddythotic (ProLab) and cites very good results with the device.

   Often Dr. Valmassy will add additional forefoot and rearfoot posting to the prefabricated device and customize it for the child. When children develop a heel-toe propulsive gait, he switches to a more standard type of Root or Blake type of functional foot orthoses and typically utilizes a deep heel cup from 18 to 20 mm as well as a flat rearfoot post.

Q:

What are the caveats and what modifications do you employ in prescribing orthoses for the patient with lower extremity equinus?

A:

It is essential for Dr. Valmassy to determine whether the equinus is congenital or if it is secondary to a pronated foot. He says congenital equinus is often compensated by excessive subtalar and midtarsal joint pronation to allow independent forefoot dorsiflexion on the rearfoot. Pronation-related equinus occurs when the foot is pronated from some other cause, which results in a secondary contraction of the posterior muscle group due to the excessive flexibility of the forefoot to rearfoot, according to Dr. Valmassy.

   If the patient has a true congenital equinus, Dr. Valmassy says you need to determine whether you want to achieve some degree of symptomatic relief for the patient prior to initiating surgery or if you want the patient to use an orthotic in lieu of surgery. Most often, he says patients will better tolerate the pronated device. Dr. Valmassy adds that patients often cannot tolerate a neutral device as it causes discomfort and patients can break the orthotic as the pronatory force is much stronger than the orthotic device.

   Dr. Valmassy emphasizes that if one can control a pronated foot in a patient with a congenital equinus, the individual will develop compensation at another level. Therefore, he suggests assessing the patient for potential genu recurvatum at every visit when there is a suspected congenital equinus. If genu recurvatum develops in a patient with equinus during the course of treatment with a functional foot orthosis, Dr. Valmassy advises clinicians to immediately stop the orthotic treatment and consider surgical intervention.

   Dr. Volpe notes that if one does not recognize the equinus influence in the clinical exam and incorporate management of the equinus into the treatment plan, there will be a higher complication rate with orthoses. If the tension remains on the heel cord and there is semi-rigid control under the midtarsal joint, he notes a great likelihood that the patient will pronate into the shell at this joint, which will cause discomfort.

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