Evaluation of pediatric and adult flatfoot deformities
foot and ankle specialist
Pediatric flatfoot is a common yet challenging deformity. Infants are usually born with a flexible flatfoot and typically do not develop a normal arch until they are 7 to 10 years old. One of the biggest challenges for the physician is differentiating a normal or physiologic flatfoot from the pathological deformity.
The astute foot and ankle surgeon should be able to differentiate a physiologic flatfoot from the pathological deformity, make an accurate diagnosis and determine a proper course of treatment. Fortunately, most flexible flatfeet are physiologic and asymptomatic, and require no treatment.1-3 One may opt for periodic observation but this is just to monitor for any progression of deformity.
Researchers have shown that pathologic flexible flatfoot in children has an incidence ranging from 2.7 to 4 percent.4-8 These are the deformities that require treatment. If left untreated, these pathologic flatfoot deformities usually progress and result in painful, disabling end stage pes valgo planus feet.
Pertinent Keys To The Diagnostic Workup
When it comes to the patient history, one should determine the onset of deformity, progression of the deformity, pain associated with deformity, whether there is a family history of foot deformities and concurrent medical conditions such as neurological disorders. Although some degree of pain is usually associated with a pathologic flatfoot, the absence of pain does not mean treatment is not warranted.
In regard to the physical exam, physicians should assess the overall severity of the deformity, range of motion and flexibility of the deformity as well as muscle strength and spasticity. Podiatric surgeons should also evaluate areas of tenderness and the patient’s gait.
One should evaluate the foot in both a weightbearing and non-weightbearing attitude. Children with a flexible flatfoot typically present with a relatively normal appearing foot and arch when they are non-weightbearing. However, when these patients are weightbearing, calcaneal eversion and collapse of the medial longitudinal arch will typically result. Other clinical findings may include medial bulging of the talar head, excessive forefoot abduction and equinus. Although pes valgo planus is typically a triplanar deformity, often the deformity is dominant in one plane. Therefore, one should assess planal dominance in order to facilitate proper treatment including the appropriate selection of surgical procedures.
Weightbearing radiographs typically show an increase in the talocalcaneal angle, an increase in the talar declination angle and an increase in the calcaneocuboid angle. The calcaneal inclination angle is usually decreased and there can be an anterior break in the cyma line. If you are suspicious of a tarsal coalition, you can pursue further imaging studies such as a CT or MRI for a more complete evaluation.
What Are The Initial Conservative Care Options?
Treatment protocols vary greatly and depend on many factors including the severity of the deformity, the flexibility of the deformity, the progression of the deformity, pain associated with the deformity and the age of the child.
Unless severe deformities (such as vertical talus) are present, conservative therapies are typically the only form of treatment I will perform on children under the age of three. Podiatric physicians can perform serial casting and manipulation for those under the age of 1. At this age, the foot is still somewhat moldable and one can often obtain correction of the deformity. While physicians may also attempt casting for those over the age of 1, the results are usually not as good and children are often reluctant to submit to casting once they have begun to walk. Bracing is another option, which can be utilized when the child is asleep.
When Surgical Repair Is Indicated
Indications for surgical repair include failure of all conservative therapies to reduce the patient’s pain or prevent progression of the deformity. Surgical considerations include severity of the deformity, flexibility of the deformity, planal dominance, concomitant medical conditions as well as the patient’s age and functional demands.
Surgical procedures generally fall into four categories: soft tissue, arthroereisis, osteotomies and arthrodesis. The goal of surgery for the pediatric patient is to reduce or eliminate pain, reduce deformity and restore normal joint alignment, and preserve joint motion when possible.
There are many soft tissue procedures podiatric surgeons can use in the correction of pediatric flatfoot deformities. With most of these procedures, the goal is to stabilize the medial arch or correct for an equinus deformity. Although these soft tissue procedures can be very effective, they are typically adjunctive procedures and are rarely successful as isolated techniques for the correction of flexible flatfoot.
The arthroereisis implant is extra-articular and limits excessive or abnormal motion across the subtalar joint. One places the implant in the sinus tarsi. The implant blocks abnormal anterior talar displacement and adduction, and prevents calcaneal eversion. This repositioning then allows the subtalar joint to function in a corrected position. I prefer this technique in the younger patient between the ages of 3 and 12 who has a flexible deformity. After placing the arthroereisis implant, one should assess the medial arch to determine if there is any remaining deformity, which requires adjunctive procedures to ensure adequate correction. It is critical that the surgeon also identify and correct any existing equinus deformity.
Various authors have described the use of arthroereisis for correction of flatfoot deformities in the older child and adult populations. However, I usually prefer osteotomies over arthroereisis when it comes to the surgical correction of flexible flatfoot deformities for most patients in their adolescent years.
A Closer Look At Osteotomy Procedures
For the adolescent or pre-adolescent child who has more significant deformities, I will typically perform an Evans calcaneal osteotomy as the primary surgical procedure.
The Evans calcaneal osteotomy is a powerful procedure that provides triplanar correction. When it was first popularized, it was primarily utilized as a procedure to produce correction in the transverse plane. However, correction also occurs in the sagittal and frontal planes as well. This laterally based opening wedge osteotomy effectively lengthens the lateral column and reduces the forefoot abduction and transverse plane deformity. In addition, surgeons can achieve realignment of the midtarsal joint and reduce calcaneal eversion and frontal plane deformity. This procedure also places tension on the long plantar ligaments and provides significant arch elevation and stabilization. This subsequently reduces the sagittal plane deformity.
Although this procedure places the peroneus longus tendon under tension via lengthening of the lateral column, a forefoot supinatus deformity typically persists and one must address this. In most cases, the Evans calcaneal osteotomy is accompanied by additional procedures in order to reduce the forefoot varus and stabilize the medial column. Most commonly, I perform a Cotton medial cuneiform osteotomy with or without additional soft tissues procedures in the medial arch. The Cotton osteotomy can effectively plantarflex the medial column and aid in stabilization.
If there is an equinus deformity, one can correct this with a gastrocnemius recession or Achilles tendon lengthening as indicated.
Although the Evans calcaneal osteotomy provides for triplanal correction, it is primarily geared toward transverse plane deformities. If a frontal plane deformity is dominant or remains after correction with an Evans calcaneal osteotomy, the surgeon can perform a medial displacement osteotomy in the posterior calcaneus.
This posterior calcaneal displacement osteotomy restores the normal angle of the long axis of the calcaneus to the floor and neutralizes abnormal pronatory forces. The medial shift of the posterior calcaneus alters the pull of the gastrocnemius-soleus muscle group slightly medial to the axis of the subtalar joint. This effectively places the Achilles tendon slightly medial and increases the varus pull on the hindfoot.
Weighing The Merits Of Arthrodesis
When selecting surgical procedures for the correction of pediatric flatfoot deformity, one should attempt joint salvage and maintain joint motion whenever possible. However, there are some patients in whom joint salvage is not possible in order to obtain adequate correction of the deformity and reduce pain. This is particularly true for subtalar joint coalitions. Due to the significant restriction of the joint motion, secondary arthritic changes often occur and joint salvage is impossible. If one cannot adequately reduce the deformity and obtain a stable foot with joint salvage procedures, the surgeon must consider arthrodesis even in the pediatric patient.
Although surgeons occasionally have to perform rearfoot arthrodesis procedures in the pediatric patient in order to obtain a successful surgical result, there is altered foot function after these procedures. However, arthrodesis procedures of the medial arch can allow for good correction and stability while the foot remains functional.
When it comes to arthrodesis of the naviculocuneiform joint for the correction of pediatric flatfoot, surgeons typically do not utilize this as an isolated technique but rather as an ancillary procedure. If significant deformity remains in the medial arch after other procedures such as an Evans calcaneal osteotomy, I will commonly perform a naviculocuneiform arthrodesis. This is particularly effective when one appreciates a significant naviculocuneiform fault or sag. This is a powerful procedure and provides great support and stability to the medial longitudinal arch.
In addition, if a hallux abducto valgus deformity is present, the surgeon can perform a Lapidus or first metatarsal cuneiform arthrodesis. This procedure not only corrects the bunion deformity but it also provides additional stability to the medial arch.
Treatment of pediatric flatfoot can be very rewarding. Patient age, severity of deformity, and flexibility of the deformity should help guide your treatment protocol. One should always attempt conservative treatments prior to any surgical intervention. The goal of surgical reconstruction is to produce a stable, functional, pain-free foot.