Infants are born with a fat pad in the arch are making their feet appear flat. The key word is “appear” because the shape of the foot is determined by bone structure, not the soft tissues.
Arch height refers to the architecture of the foot, that is, one may have an arch which is high, low or medium. One may have a low arch which is very stable or a high arch which is not stable but rolls inward, also known as “pronation.” All feet need to roll in to a certain extent for the purpose of absorbing shock but excessive pronation or overpronation can be a problem.
The clinical concern is foot stability more so that arch height. A foot that overpronates or rolls in excessively can delay walking and lead to juvenile bunions (enlarged growths on the big toe joint) and reduced ability to push off (propulsion).
Overpronation may be caused by ligamentous laxity or too much flexibility in the arch joints, by congenital
deformities such as extra bones in the arch, and occasionally genetic problems.
Treatment options for problematic flat feet or significant overpronation include:
1) Modified shoegear with arch support and wedges on the inside (medial wedges) to reduce the amount that the feet roll in.
Prefabricated orthotics can be used in milder cases. Custom foot orthotics may be needed in more advanced cases including the UCBL (University of California at Berkeley) design. Another design is known as an SMO or supramalleolar orthotic. It is based on the idea that an orthotic that goes up higher works better. We find that when a UCBL is well made, the need for an SMO is uncommon.
Knock knees (genu valgum) can be worsened by the feet rolling in or overpronation.
Surgical treatment of pediatric flatfoot
One of the most challenging aspects of treatment of pediatric flatfoot is understanding who needs surgery or not. Dr. Davis, a pediatric podiatrist in San Antonio, believes that it is important to use conservative treatments such as custom prescription foot orthotics as early as possible. Children do not outgrow such issues. Often, what seem to be significant deformities, treated early, can be resolved with conservative treatment. If such issues are not completely resolved, then surgical treatment can be less extensive.
A common mistake is to view the pediatric flatfoot in a similar fashion to adult flatfoot. Pediatric flatfoot deformities can have a number of causes beyond what appears to be a flat foot such as tarsal coalitions (boney bridges across joints) which can change the position of the bones of the foot, accessory navicular bone (an extra bone in the arch of the foot) that weakens the arch or equinus which is a short heel cord (Achilles tendon). It is important that the doctor determine the causes and be able to address all the causes of the problem.
Another misconception involves confusing a flat appearing foot with a foot that rolls in too much or overpronation. Flatness, by itself, is not always a problem. It is possible to have feet that are flat but stable and function well. Pronation or overpronation is a form of instability in which the arch lowers when the foot and ankle roll inward. An effective prescription orthotic, provided to a 14 month old toddler can often lead to significantly improved stability after a couple of years.
Surgical treatment need be focused on the underlying causes of overpronation.
1) Soft tissue surgery: This may involve lengthening of a short Achilles tendon.
2) Joint surgery: Such surgery may include fusion of unstable joints. Joint surgery should be avoided in children whenever possible. The position of joints can be changed by moving bones around the joints thereby changing their position. One form of joint surgery is known as arthroeresis in which the surgeon places a small device, essentially a plug, in the subtalar joint. The subtalar joint is the joint below the ankle that allows the foot to pronate. This procedure basically reduces the excess inward motion of the joint. It is simple and noninvasive. It is generally not a stand alone procedure and need be combined with other procedures.
3) Removal of an accessory navicular bone. This is an inherited condition in which an extra bone is present in the arch. The navicular is the bone that forms the keystone or high point of the arch. A tendon, tibialis posterior, runs down the inside of the leg and ankle, attaching the the navicular and pulling upwards on the navicular. Children with accessory navicular bones have a posterior tibial tendon that attaches to the accessory bone instead of the navicular, allowing the arch to drop down more and flatten. Sometimes removal of the accessory navicular bones is necessary. The procedure includes re-attachment of the bone to the navicular itself and is known as a Kidner Procedure.
4) Reorienting the direction of bones around the joints. This involves a number of procedures:
a) Cotton procedure: This involves raising the arch height by placing a wedge in the internal cuneiform bone on top of the arch.
b) Koutsogiannis procedure or medial calcaneal slide procedure: This involves moving the weight bearing portion of the heel bone toward the inside of the foot effectively raising the back part of the arch.
c) Evans procedure: This procedure involves lengthening the part of the heel bone which forms the outside of the arch.
Most flatfoot reconstruction surgery involves a combination of procedures. Again, Dr. Davis feels strongly that effective conservative treatment should be the first step. Should surgical treatment be necessary, he can offer decades of experience and expertise to achieve the best possible results.