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Foot Deformities in Infants and Children
Common Orthopedic Problems
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Foot Deformities in Infants and Children Dennis R. Wenger, M.D. * and Judy Leach, R.P. T. t
Children's foot deformities should be considered in two categories as described by Williams: 5 first, true embryonic malformations ("manufacturing defects") and second, positional or postural abnormalities, ("packaging defects"). The latter, secondary to a confined intrauterine environment, can be expected to improve rapidly after birth. In this article we will describe the common foot deformities of infancy and childhood in a manner that should allow a pediatrician or primary care physician to accurately diagnose a child with a foot deformity and appropriately refer to an orthopedic surgeon.
INITIAL EXAMINATION (NEONATE)
An infant or child with a foot deformity requires a brief general orthopedic examination, which includes observation of the following: (1) Does the child hold his or her head straight and have full neck range of motion? (Rule out torticollis.) (2) Does he or she move his/her upper extremities normally? (3) Is the back straight? Are there any palpahle or visihle spinal defects? (Skin discoloration, normal mongolian spots versus hemangioma, pigmented defects associated with spinal dysrhaphism.) (4) In a child under age 1 year with a foot deformity, examine for hip dysplasia. Kurman and MacEwen l have documented the high incidence of congenital hip dysplasia (CDR) associated with metatarsus varus. In the child over age 2 to 3 months, limited hip abduction is the only finding associated with hip dysplasia; the Ortolani sign is no longer present, because by this age the hip is fixed in an abnormal position. Unfortunately, the physical examination for mild hip dysplasia is extremely unpredictable. Therefore, some orthopedic centers advise a pelvic radiograph for all children with *Staff Pediatric Orthopaedic Surgeon, Children's Hospital; Assistant Clinical Professor, Orthopaedic Surgery, University of California, San Diego, California tStaff Physical Therapist, Children's Hospital; Research Associate, Pediatric Orthopedic and Scoliosis Medical Group, San Diego, California
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significant metatarsus varus. We do not take routine hip radiographs but instead obtain them only when the child has risk factors for CDH (breech, female, first-born) or has physical findings (limited hip abduction). (5) Examine the feet.
THE FOOT AS AN INDICATOR OF GENERALIZED DISEASE The above sequence emphasizes that a generalized disease can produce a deformed foot and that often the generalized disorder is more important than the foot problem. Neurologic disorders that can produce foot deformity include spina bifida, cerebral palsy, sacral agenesis, sacral lipoma, Friedreich's ataxia, Charcot-Marie-Tooth disease, Duchenne's muscular dystrophy, spinal cord tumor, brain tumor, and other conditions. Thus the neurologic examination, although brief, must be sensitive enough to screen for these conditions. Observing the child walk, tiptoe walk heel walk, hop on one foot and then the other, and finally run provides a brief but powerful screening tool.
CLARIFICATION OF THE "BIG THREE" The three most common neonatal foot disorders requiring differential diagnosis include: (1) calcaneovalgus foot, the most common congenital foot disorder, rarely requiring treatment; (2) metatarsus varus, which may require treatment at age 2 to 3 months; and (3) talipes equinovarus (clubfoot) which requires immediate treatment. We will describe a foot examination sequence that should distinguish between these three disorders, allowing accurate diagnosis and referral when required.
THE DIAGNOSTIC MATRIX Newborn feet appear rather nondescript and very much alike. You may feel about as comfortable describing a neonatal foot deformity in the medical chart as does an orthopedic surgeon describing retraction of a tympanic membrane. The seemingly "abnormal" foot can be immediately referred to an orthopedic surgeon with the generic term "possible clubfoot" applied. However, a brief examination of three anatomic features should allow you to distinguish between the three common foot disorders and determine the urgency for referral. Completion of the diagnostic matrix includes documentation of the following three features: (1) Side view: Can the foot be dorsiflexed well above neutral? (Fig. lA) Or is the foot in fixed equinus (plantarflexion/tight heel cord/tiptoe position)? (2) Foot shape-sole-viewed from bottom: kidney bean shape (deviated medially), seen in clubfoot and metatarsus varus (Fig. IB), or banana shape (deviated laterally), seen in calcaneovalgus (Fig. 2B).
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Figure 1. A, Side view of a foot. There was a question whether the child had a clubfoot or metatarsus varus. The foot can be dorsiHexed freely, therefore this cannot be a clubfoot. B, Foot viewed from the bottom. The kidney shape can be seen in either a clubfoot or metatarsus varus. This child had metatarsl!S varus.
(3) Heel position-viewed from behind: Is the heel in varus or valgus? This third factor, the most difficult for the non-orthopedist to define, requires two stages of learning to make the judgment: (a) What are heel varus and heel valgus as viewed from behind? (Fig. 3A) Heel varus-heel deviated medially. Heel valgus-heel deviated laterally. (b) Heel position in normal infants and adults varies from varus to valgus depending on whether the forefoot is in neutral or in plantarflexion (equinus). To evaluate heel position for the diagnostic matrix, the forefoot must be brought up to the neutral position and the heel viewed from behind (Fig. 3B).
Figure 2. A, Classic calcaneovalgus feet in an infant. The long, gracile foot can be dorsiHexed against the tibia. B, Same feet viewed from the bottom. The lateral deviation (banana shape) is characteristic of il calcaneovalgus foot.
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Figure 3. A, Feet viewed from behind. Both heels are deviated medially and the heels appear to be in varus. B, Same feet viewed from behind but with attempt to dorsiflex forefoot. The left foot dorsiflexes and the heel now deviates laterally into valgus (a metatarsus varus foot). The right f()ot cannot be dorsiflexed, and the heel remains in varus (clubfoot).
A clubfoot cannot be brought up to neutral dorsiflexion. Therefore, the heel remains in fixed varus whether the forefoot is in plantarflexion or attempted forced dorsiflexion. Infants with calcaneovalgus and metatarsus varus demonstrate heel valgus when the foot is dorsiflexed. In metatarsus varus, however, if the forefoot is allowed to drift into equinus, the heel will appear in varus. It can thus mimic a clubfoot. Assessment of heel varus or valgus may be difficult to learn, but once mastered, allows you to make the sometimes difficult differentiation between a mild clubfoot (which requires immediate referral) and metatarsus varus (which can be observed, stretched, and referred at age 2 to 3 months if not improved). . In review, there are three common neonatal foot disorders and three parameters must be documented to make the differential diagnosis. This can be summarized as in Table 1.
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Table 1. Diagnostic Matrix-Three Common Foot Deformities CALCANEOVALGUS
Side view (can foot dorsiflex'?) Foot shape (bottom view) Heel position (viewed from behind)
METATARSUS VARUS
CLUBFOOT
Yes
Yes
No
Banana shaped (deviates laterally)
Kidney shaped (deviates medially) Valgus
Kidney shaped (deviates medially) Varus
Valgus
"THE BIG THREE": TREATMENT AND NEED FOR REFERRAL Calcaneovalgus Foot In this postural or "packaging" defect, the most common newborn foot deformity, the laterally deviated banana-shaped foot folds against the anterolateral surface of the tibia (see Fig. 2A and B). The heel cord is stretched and abnormally long. This positional deformity should improve rapidly and spontaneously. Thoughtful parents, appropriately suspicious of your optimistic prognosis, dislike doing nothing. They should be encouraged to exercise the foot each time they change the child's diaper, stretching the dorsal tendons and ligaments. In rare cases, the foot remains severely deformed and requires corrective casts. This occurs perhaps once every 2 years in a busy pediatric orthopedic practice. The resistant case may only partially correct, appearing later as one of the subgroups with flexible flatfoot. Finally, the rare severe case must be differentiated from congenital convex pes valgus, better known as congenital vertical talus. Half of this group are associated with neurologic disorders, such as arthrogryposis or spina bifida. The vertical talus foot has a tight heel cord, whereas the calcaneovalgus foot does not. In a vertical talus foot, the hindfoot is in equinus (heel cord tight) while the forefoot is folded against the anterolateral surface of the tibia. The foot is broken down in the midfoot, with a "rocker-bottom" appearance. Metatarsus Varus (Metatarsus Adductus) The terms metatarsus varus and metatarsus adductus technically describe slightly different forefoot variations but in practice are used synonymously. The diagnostic matrix helps to clarify diagnosis: the foot can easily be dorsiflexed (heel cord is not tight) and when viewed from behind with the forefoot dorsiflexed, the heel is in valgus (deviated laterally). In contrast, a mild clubfoot cannot be dorsi flexed to neutral and the heel remains fixed in varus. A metatarsus varus deformity may be unilateral or bilateral and is probably the result of intrauterine position ("packaging" defect). Commonly, infants present with one metatarsus varus foot and the other foot in calcaneovalgus ("wind-blown feet").
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Figure 4. A, Mild bilateral metatarsus varus. B, Left foot viewed from below-note charact!"ristic kidney shape. C, The foot is easily correctible with gentle passive stretching; cast correction is not required. D, Moderately severe metatarsus varus foot. This more fixed deformity requires referral for corrective plaster casts.
As is true of all "packaging" defects, metatarsus varus feet usually improve in the first few months of extrauterine life. The initial examination should document severity: (1) mild, flexible (Fig. 4A to C); (2) moderate, fixed (Fig. 4D); (3) severe, rigid. You should also rule out associated deformities, especially hip dysplasia. The metatarsus varus foot does not require immediate referral. Instead, we recommend that the parents stretch the child's foot. The mechanically correct way to stretch a metatarsus varus foot includes firmly grasping and stabilizing the heel to avoid producing even more heel valgus. Then stretch the forefoot laterally and hold for a count of five, pushing hard enough to cause the baby to perhaps wince, but not cry. Repeat the exercise five times with each diaper change. In mild, passively correctible cases (Fig. 4A to C); the rapid improvement by age 2 months makes orthopedic referral unnecessary. Feet with moderate, fixed deformity do not correct adequately with stretching alone and remain deformed at age 2 months. Hold the child in the standing position to determine how the feet look in a weight-bearing position (Fig. 4D). This position adds the dynamic component and reproduces the severity of deformity which worries the parents. At age 2 months, these children should be referred to an orthopedic surgeon, who can evaluate the child to determine if serial corrective casts are required.
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Referral at age 2 to 4 months (at the latest) allows for cast correction while the foot is pliable. After age 6 months, cast correction is almost impossible owing to foot stiffness and vigorous kicking by the robust child. The reasons for treating these feet are controversial and treatment indications vary according to the orthopedic surgeon consulted. However, most foot specialists relate many common adult foot problems (bunions involving great toe, callosities laterally at base of fifth metatarsal) to metatarsus varus not treated in childhood. A series of three or four corrective plaster casts, applied at 1- to 2week intervals, provides rapid correction. Expert application corrects the forefoot and avoids worsening of heel valgus and the resultant tendency towards flatfoot. Corrective casts for metatarsus varus are not identical to casts for clubfoot. Ponseti's important review clarifies this issue. 2 We do not advise corrective shoes alone for treatment of metatarsus varus except cases in which the child has not been referred until age 4 to 6 months and cast correction is impossible because of stiffness and patient size. In these larger children with a bothersome residual deformity, we often resort to straight last shoes plus a Friedman counter splint (leather strap between heels to keep feet everted during sleep). These children usually have significant associated medial tibial torsion and the combination of corrective shoes plus counter splint provides some apparent improvement. We urge that children with significant metatarsus varus be referred, ideally at age 2 months and at the latest 4 months, to avoid this difficult circumstance. When a child requires corrective casts, we follow the cast treatment with straight last shoes worn full time (day and night) for 2 to 3 months to maintain the correction gained with casts. The shoes must be removed several times daily for skin inspection and for bathing. The straight last shoes are subsequently worn as a walking shoe until age 18 months. Our empiric formula has not been scientifically documented but is offered as a guideline. We do not routinely apply a Denis Browne bar to the shoes at night, since the external torque of the bar may exacerbate already present heel valgus. Finally, the extremely rigid, almost teratologic bilateral metatarsus varus includes a fixed midfoot joint deformity that will not respond to conservative treatment. These rare cases should be referred in the first few weeks of life when neonatal ligamentous laxity makes serial corrective casting easier. Some of these children will require corrective surgery, usually at age 2 to 4 years. Metatarsus Primus Varus (with Abducted Great Toe). Occasionally, infants present with only moderate metatarsus varus but maintain an extremely abducted (medially deviated) great toe, making shoe and sock donning difficult. These feet sometimes require a minor surgical release of the abductor hallucis tendon between age 6 to 18 months. The predictable cosmetic improvement pleases parents. Clubfoot (Talipes Equinovarus). As clarified in the diagnostic matrix, a clubfoot is kidney shaped and fixed in equinus, with heel varus (Fig. 5A and B). Mild cases may represent "packaging" defects; however, the more severe, fixed cases suggest "manufacturing" defects, including possible
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Figure 5. A, Typical bilateral clubfoot, viewed from below. B, Clubfoot viewed from above.
abnormal talar shape. Associated deformities should be eliminated, especially congenital hip dysplasia. In bilateral cases, we recommend a hip radiograph be performed some time during the treatment course. Possible etiologic factors (arthrogryposis, spina bifida, myotonic dystrophy, etc.) must be considered. A clubfoot requir~s immediate referral for corrective casts, applied by an interested, qualified orthopedic surgeon. Starting the correction during the first week oflife provides better correction because the infant's ligaments remain lax secondary to maternal hormones. Starting the cast correction in the neonatal nursery has some emotional appeal; however, the "technical" environment, lack of cast materials, lack of an experienced assistant to hold the foot, and so forth prevent ideal cast application. If the infant is healthy and will be discharged in a day or two, we prefer to apply the first cast within the first 3 or 4 days of life in our office or clinic, where conditions are ideal. Adhesive taping or strapping, another widely accepted method for maintaining the corrected position after manipulation of clubfoot, is not widely used by North American orthopedic surgeons. A series of four to eight casts, applied weekly, provides significant correction and is followed by shoes attached to a Denis Browne splint (or other splinting method) to maintain correction. The splint is worn full time for several months and then at night and naptime until age 1 year (or until surgical correction in severe cases). Children with more severe clubfoot deformities will require surgery some time later in the first year of life to obtain full correction. The percentage of children with clubfoot who require major surgery (posteromedial release) to complete their correction varies greatly from region to region. Some orthopedic surgeons insist on complete "anatomic" clinical and radiographic correction; thus, 75 per cent of their patients require major surgery. Others are more successful with cast correction, accepting mild residual clinical and radiographic deformity. They operate on fewer than half of their clubfoot patients.
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FLEXIBLE FLATFOOT Flexible flatfoot, an extremely common childhood disorder, becomes apparent when the child begins standing. The normal fatty tissue cloaking the infant foot often makes distinguishing a flatfoot from a slightly fat foot difficult. Most children with flexible flatfeet have loose ligaments, allowing their loose jOinted feet to sag when they bear weight (Fig. 6A). Most flatfooted "patients" come from families with loose ligaments and flatfeet (Fig. 68). Not only are their feet loose jointed, but they usually have hyperextendible knees, elbows, and fingers. If these children walked on their hands, they would also have flat hands. Initial assessment includes a review of the family history, the birth history of the child, and a brief screening examination to rule out a serious condition as a cause for the flatfoot. Have the child stand on his tiptoes (Fig. 7A and 8). If an arch forms with the foot in the tiptoe position and the heel rolls into varus (deviates medially), you can be quite certain that the child has good muscle power in the ankle and foot. Children with flexible flatfeet due to ligamentous laxity form a good arch in the tiptoe position. Clearly, a tight heel cord can produce a secondary flatfoot. We see this pattern in mild cerebral palsy (increased deep tendon reflexes), congenital tight heel cords (normal deep tendon reflexes), and muscular dystrophy.
Figure 6. A, Typical flexible flatfeet. The ankles roll medially and the child appears to be walking on the medial side of his foot. His parents and siblings also have flatfeet. B, Another loose-jointed "patient" with flatfeet. All of his relatives are similarly affiicted.
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Figure 7. A, A child with flatfoot, viewed from behind. The heels are in mild valgus. B, The same child, standing on tiptoe. Note that the heel rolls into varus and an arch is formed. Thus the child has a flexible flatfoot.
Have the child sit on the floor and then ask him to stand. This test for proximal muscle weakness (positive Gower's sign-patient uses hands on thighs to assist quadriceps) helps you to screen the Duchenne's muscular dystrophy patient who can present with flatfoot (and heel cord tightness). Occasionally, children present with a stiff, painful flatfoot that can be caused by tarsal coalition, trauma, benign or malignant bone tumors, occult infection, foreign body, Kohler's disease, and other disorders. Children with a stiff or painful flatfoot should be referred to an orthopedic surgeon for further evaluation. We do not perform routine radiographs in children with flexible flatfoot. In contrast, the child with stiff, painful flatfoot will need specific radiographs, which should be performed by the orthopedic consultant. (Note: foot pain will be presented in greater detail elsewhere in this issue.) Treatment
Flatfoot treatment indications remain controversial. Usually, the parents want their child to have "proper treatment" to avoid the flatfootedness that they endured as children. They usually wore corrective shoes in childhood and feel bound to provide similar or better treatment for their child. They assume that modern medicine would have produced a treatment method far superior to the one they had as a child. Traditionally, flatfooted children have been treated with corrective shoes including modifications intended to improve the arch (scaphoid pad). Others, particularly podiatrists, have emphasized the use of custom-molded plastic inserts worn within regular shoes. The trend for orthopedic surgeons, particularly pediatric orthopedic surgeons, has gradually evolved to not recommending corrective shoes or inserts because they are expensive, often cumbersome, and have not been demonstrated to change the natural history of flexible flatfoot. Staheli has emphasized the lack of scientific evidence for the efficacy of corrective shoes in children. 3 Recently, we completed a study of 100 children with flexible flatfoot enrolled in a prospective trial designed to compare the results of vigorous flatfoot treatment to prospective, randomized, untreated controls. 4 We were unable to document that corrective shoes or inserts had any effect on the natural history of flexible flatfoot.
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We now recommend that a child with flexible flatfoot, without significant symptoms or severe shoe wear problems, wear ordinary shoes (usually a well-fitted sneaker). We recommend special shoes only in the rare child with signifi{:!ant persistent pain or a deformity so severe that ordinary shoes wear out within a few weeks. Parents often remain unconvinced when advised that flatfoot cannot be treated, rarely understanding the somewhat esoteric concept of the natural history of a condition not being affected by intervention. Therefore, despite our advice, many parents will seek out a podiatrist or another physician who will fulfill their wish for their child to have corrective shoes or inserts.
CAVUS (HIGH-ARCHED) FEET A slightly high-arched foot and clawed great toe in infancy is a normal finqing, perhaps reflecting intrauterine position. Many older children have normal but high-arched feet, often inherited from their parents. Their feet do not require specific treatment; however, the cavus or high-arched foot leads to more shoe fitting problems than does a flatfoot. The gradual development of a cavus foot in a child may indicate a neurologic disorder (spinal dysraphism, Charcot-Marie-Tooth's disease, Friedreich's ataxia). Therefore, a child with a significant cavus foot requires a careful neurologic examination with referral to a neurologist or orthopedic . surgeon, its indicated.
TIPTOE WALKING Children often walk on their tiptoes (equinus gait), particularly during the first 2 years of walking (age 1 to 3 years). The common sporadic tiptoe gait, often a habit, requires no attention or treatment. Persistent cases can be placed in one of three categories: (1) Habitual toe walking-with the child relaxed, the foot can easily be dorsiflexed above neutral; (2) Mild cerebral palsy-deep tendon reflexes are brisk, running intensifies the deformity, the equinus cannot be completely corrected; and (3) Congenital tight heel cords (rare but definite entity)--foot cannot be dorsiflexed, even with the child relaxed (or under anesthesia). The deep tendon reflexes are normal and the child has no neurologic deficit. Careful study should clarify the pattern. Habitual toe walking should resolve with time. The cerebral palsy toe walker should be referred through usual channels for evaluation and treatment. The child with congenital tight heel cords should be referred to an orthopedic surgeon. The equinus often responds to serial corrective casts but may require surgical heel cord lengthening.
ADVICE ABOUT SHOES We currently do not prescribe corrective shoes for mild foot disorders in children, particularly flatfoot. We do recommend straight last shoes for
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maintenance of correction following serial corrective plaster casts or surgery in children with metatarsus varus or clubfoot. Mounting evidence suggesting that corrective shoes and inserts do not change the natural history of flexible flatfoot 4 supports Staheli's3 contention that children should wear a comfortable, soft shoe that fits well. In practice, this is usually a lightweight sneaker. Patients with moderate flatfoot or other foot imbalance do not get good mileage from running/jogging shoes, which currently are the most available (and socially acceptable) child's shoe. These shoes are designed for straightforward jogging or running and not for side-to-side motion (cutting sports), which rapidly destroys the shoe. Thus, a shoe fashioned after a basketball or tennis shoe (with rolled rubber edges on the sides and ends) provides greater durability and is particularly advised for children with shoe wear problems. Sandals are extremely popular and usually lightweight; however, the loose attachment of the sandal to the foot may cause the child to appear clumsy. The weight of a heavy leather "orthopedic shoe" often makes a child's gait more cumbersome, thus we recommend a lightweight shoe. Shoe modifications cannot control and correct rotational deformities such as tibial torsion or femoral anteversion and are not prescribed (alone) for these conditions. Denis Browne splints, attached to shoes and worn at night, are sometimes used to correct tibial torsion. In summary, pediatric orthopedic surgeons rarely prescribe corrective footwear. There is little evidence to suggest that cultures with fastidiously shoed children produce adults with better feet. OTHER COMMON FOOT CONDITIONS
Polydactyly Polydactyly, a relatively common autosomal dominant foot disorder, most commonly presents as an extra toe on the lateral border of the foot (Fig. 8). Occasionally, the extra digit occurs medially. A duplicated great toe, appearing as a bifid toe growing with the normal great toe, often emanates from a partially duplicted phalanx. Complex planning is required for successful surgical excision. You should refer children with polydactyly to an orthopedic surgeon at age 1 or 2 months to allow family counseling and planning for surgery. \Ve usually remove the extra digit between age 6 months and 1 year. The surgical plan becomes clearer as the child nears 1 year of age, and the cartilage and bony structures become better defined radiographically, particularly in a duplicated great toe.
Syndactyly Complex syndactyly involving multiple toes rarely occurs, and when it does we do not advise surgical separation. A partial syndactyly between the second and third toes, usually bilateral, is much more common (Fig. 9). The webbing represents a variation of normal embryologic development,
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Figure 8. Child with complex polydactyly. Both the great toe and the "fifth" toe are duplicated.
making the second and third toes appear as though they are growing from a single stalk. The underlying bones are normal. A similar deformity in the hand would be separated surgically to improve function; however, toe syndactyly rarely impedes function, thus surgical separation is not indicated. Surgical separation almost always requires skin grafting, thus the risk/benefit ratio seems excessive for a cosmetic deformity. Bunions in Adolescents Teenagers often develop a prominent first metatarsal head and radiographic findings of an increased angle between the first and second
Figure 9. An extremely common form of syndactyly (partial). No treatment is advised.
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Figure 10. Anteroposterior foot radiograph demonstrating bunions in an adolescent. The medial deviation of the first metatarsal produced a bump (bunion) at the base of the great toe. The patient was advised to wear soft shoes, which relieved her symptoms.
metatarsals (Fig. 10). In addition, the great toe deviates laterally, producing a hallux valgus or bunion deformity. The disorder is almost always bilateral. Treatment includes changing to soft, pliable shoes that accommodate the deformity. More severe deformities make boot fitting painful and difficult, particularly for figure skating, ice hockey, skiing, and other sports requiring tight boot fit. In these cases, we advise surgical correction, which includes straightening of the first metatarsal, removing the bump of bone on its medial-distal end, and tightening of the joint capsule. Most teenage bunions do not require surgery. We perform bunion surgery on adolescents perhaps once or twice a year in a busy pediatric orthopedic practice. Fortunately, there is no cutoff point after which surgery becomes more difficult. Therefore, borderline cases can be followed into adult life, with surgery advised only if pain or shoe wear problems become insurmountable. Overlapping Toes Children sometimes present with flexion deformities of the third and fourth toes, with the second toe in a more dorsal position, causing overlapping or "curly toes" (Fig. llA and B). The child then develops calluses, especially on the tip of the curled toe. Stretching and taping do not change this position; however, most children accommodate the deformity and do not require specific treatment. When the deformity is s.evere, surgical release of the flexor tendons of the curled toes corrects the toe deformity.
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Figure 11. A, Curly toes with the second toe dorsally positioned and the lateral toes excessively flexed (curled). B, Plantar view, same foot. Callosities form on the distal pads of the lateral toes. This child required flexor tenotomy of the lateral toes to relieve symptoms.
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Figure 12. Child with overlapping or cocked-up fifth toe. This annoying position often requires surgical correction.
Occasionally, children present with overactivity of the extensor tendon, producing an overlapping or cocked-up fifth toe (Fig. 12). This position makes shoe fitting difficult and the toe will not change its position without surgery. In more severe cases, we advise correction, including dorsal skin, capsule, and tendon release combined with volar skin advancement. Bony Feet Once children lose their infantile foot fat, their feet begin to exhibit their true character. Much like human hands, human feet demonstrate incredibly wide variations of normal anatomy. Parents often worry about bumps or prominences that they note on their child's feet. Inspection may demonstrate a normal but prominent "bump" over the navicular medially, calcaneus laterally, base of the metatarsals dorsally, or base of the fifth metatarsal laterally. We often look at the child's (and parent's) hands to confirm that the bony prominences are only a reflection of the child's overall somatotype. Rarely, the prominences develop an associated bursitis and produce significant symptoms (accessory navicular medially, "pump bump" on lateral calcaneus), and will require treatment. Most bony feet are best handled by first reassuring the parents that the child is normal and then recommending soft, pliable shoes.
SUMMARY
Foot deformities may reflect a generalized disorder, especially a neurologic problem; thus, the child should have a brief general examination. Many infantile foot deformities, such as calcaneovalgus, are postural and self-correcting. Metatarsus varus is not referred for treatment until age 2 months and then only if the deformity is moderate or severe. Fixed forefoot equinus and heel varus characterize a clubfoot, which requires immediate treatment.
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Corrective shoes are not advised as the primary treatment for metatarsus varus or clubfoot but often are prescribed to maintain the corrected position after serial casts. Flexible flatfoot is a manifestation of a constitutional laxity affecting all ligaments and joints. The feet appear abnormal because of weight-bearing stresses. Most children with flatfoot achieve a partial correction spontaneously. Current research does not document that treatment with corrective shoes or inserts produces a result better than the partial correction that occurs naturally. ACKNOWLEDGMENT Our special thanks to Yolanda Nerio for her help in preparing this article.
REFERENCES 1. Kurman, J. S., and MacEwen, G. D.: The incidence of hip dysplasia with metatarsus adductus. CHn. Orthop. 164:234, 1982. 2. Ponseti, I. V., and Becker, J. R.: Congenital metatarsus'adductus: The results of treatment. J. Bone Joint Surg., 48A:702, 1966. 3. Staheli, L. T.: Corrective shoes for children: A survey of current practice. Pediatrics, 66:1, 1980. 4. Wenger, D., Mauldin, D., Speck, G., et al.: The effect of treatment on outcome in flexible flatfoot: A prospective randomized trial. Unpublished data, 1985. 5. Williams, P. F.: Orthopaedic Management in Childhood. London, Blackwell Scientific Publications, 1982.
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Foot Deformities in Infants and Children Dennis R. Wenger, M.D. * and Judy Leach, R.P. T. t
Children's foot deformities should be considered in two categories as described by Williams: 5 first, true embryonic malformations ("manufacturing defects") and second, positional or postural abnormalities, ("packaging defects"). The latter, secondary to a confined intrauterine environment, can be expected to improve rapidly after birth. In this article we will describe the common foot deformities of infancy and childhood in a manner that should allow a pediatrician or primary care physician to accurately diagnose a child with a foot deformity and appropriately refer to an orthopedic surgeon.
INITIAL EXAMINATION (NEONATE)
An infant or child with a foot deformity requires a brief general orthopedic examination, which includes observation of the following: (1) Does the child hold his or her head straight and have full neck range of motion? (Rule out torticollis.) (2) Does he or she move his/her upper extremities normally? (3) Is the back straight? Are there any palpahle or visihle spinal defects? (Skin discoloration, normal mongolian spots versus hemangioma, pigmented defects associated with spinal dysrhaphism.) (4) In a child under age 1 year with a foot deformity, examine for hip dysplasia. Kurman and MacEwen l have documented the high incidence of congenital hip dysplasia (CDR) associated with metatarsus varus. In the child over age 2 to 3 months, limited hip abduction is the only finding associated with hip dysplasia; the Ortolani sign is no longer present, because by this age the hip is fixed in an abnormal position. Unfortunately, the physical examination for mild hip dysplasia is extremely unpredictable. Therefore, some orthopedic centers advise a pelvic radiograph for all children with *Staff Pediatric Orthopaedic Surgeon, Children's Hospital; Assistant Clinical Professor, Orthopaedic Surgery, University of California, San Diego, California tStaff Physical Therapist, Children's Hospital; Research Associate, Pediatric Orthopedic and Scoliosis Medical Group, San Diego, California
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significant metatarsus varus. We do not take routine hip radiographs but instead obtain them only when the child has risk factors for CDH (breech, female, first-born) or has physical findings (limited hip abduction). (5) Examine the feet.
THE FOOT AS AN INDICATOR OF GENERALIZED DISEASE The above sequence emphasizes that a generalized disease can produce a deformed foot and that often the generalized disorder is more important than the foot problem. Neurologic disorders that can produce foot deformity include spina bifida, cerebral palsy, sacral agenesis, sacral lipoma, Friedreich's ataxia, Charcot-Marie-Tooth disease, Duchenne's muscular dystrophy, spinal cord tumor, brain tumor, and other conditions. Thus the neurologic examination, although brief, must be sensitive enough to screen for these conditions. Observing the child walk, tiptoe walk heel walk, hop on one foot and then the other, and finally run provides a brief but powerful screening tool.
CLARIFICATION OF THE "BIG THREE" The three most common neonatal foot disorders requiring differential diagnosis include: (1) calcaneovalgus foot, the most common congenital foot disorder, rarely requiring treatment; (2) metatarsus varus, which may require treatment at age 2 to 3 months; and (3) talipes equinovarus (clubfoot) which requires immediate treatment. We will describe a foot examination sequence that should distinguish between these three disorders, allowing accurate diagnosis and referral when required.
THE DIAGNOSTIC MATRIX Newborn feet appear rather nondescript and very much alike. You may feel about as comfortable describing a neonatal foot deformity in the medical chart as does an orthopedic surgeon describing retraction of a tympanic membrane. The seemingly "abnormal" foot can be immediately referred to an orthopedic surgeon with the generic term "possible clubfoot" applied. However, a brief examination of three anatomic features should allow you to distinguish between the three common foot disorders and determine the urgency for referral. Completion of the diagnostic matrix includes documentation of the following three features: (1) Side view: Can the foot be dorsiflexed well above neutral? (Fig. lA) Or is the foot in fixed equinus (plantarflexion/tight heel cord/tiptoe position)? (2) Foot shape-sole-viewed from bottom: kidney bean shape (deviated medially), seen in clubfoot and metatarsus varus (Fig. IB), or banana shape (deviated laterally), seen in calcaneovalgus (Fig. 2B).
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Figure 1. A, Side view of a foot. There was a question whether the child had a clubfoot or metatarsus varus. The foot can be dorsiHexed freely, therefore this cannot be a clubfoot. B, Foot viewed from the bottom. The kidney shape can be seen in either a clubfoot or metatarsus varus. This child had metatarsl!S varus.
(3) Heel position-viewed from behind: Is the heel in varus or valgus? This third factor, the most difficult for the non-orthopedist to define, requires two stages of learning to make the judgment: (a) What are heel varus and heel valgus as viewed from behind? (Fig. 3A) Heel varus-heel deviated medially. Heel valgus-heel deviated laterally. (b) Heel position in normal infants and adults varies from varus to valgus depending on whether the forefoot is in neutral or in plantarflexion (equinus). To evaluate heel position for the diagnostic matrix, the forefoot must be brought up to the neutral position and the heel viewed from behind (Fig. 3B).
Figure 2. A, Classic calcaneovalgus feet in an infant. The long, gracile foot can be dorsiHexed against the tibia. B, Same feet viewed from the bottom. The lateral deviation (banana shape) is characteristic of il calcaneovalgus foot.
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Figure 3. A, Feet viewed from behind. Both heels are deviated medially and the heels appear to be in varus. B, Same feet viewed from behind but with attempt to dorsiflex forefoot. The left foot dorsiflexes and the heel now deviates laterally into valgus (a metatarsus varus foot). The right f()ot cannot be dorsiflexed, and the heel remains in varus (clubfoot).
A clubfoot cannot be brought up to neutral dorsiflexion. Therefore, the heel remains in fixed varus whether the forefoot is in plantarflexion or attempted forced dorsiflexion. Infants with calcaneovalgus and metatarsus varus demonstrate heel valgus when the foot is dorsiflexed. In metatarsus varus, however, if the forefoot is allowed to drift into equinus, the heel will appear in varus. It can thus mimic a clubfoot. Assessment of heel varus or valgus may be difficult to learn, but once mastered, allows you to make the sometimes difficult differentiation between a mild clubfoot (which requires immediate referral) and metatarsus varus (which can be observed, stretched, and referred at age 2 to 3 months if not improved). . In review, there are three common neonatal foot disorders and three parameters must be documented to make the differential diagnosis. This can be summarized as in Table 1.
~
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Table 1. Diagnostic Matrix-Three Common Foot Deformities CALCANEOVALGUS
Side view (can foot dorsiflex'?) Foot shape (bottom view) Heel position (viewed from behind)
METATARSUS VARUS
CLUBFOOT
Yes
Yes
No
Banana shaped (deviates laterally)
Kidney shaped (deviates medially) Valgus
Kidney shaped (deviates medially) Varus
Valgus
"THE BIG THREE": TREATMENT AND NEED FOR REFERRAL Calcaneovalgus Foot In this postural or "packaging" defect, the most common newborn foot deformity, the laterally deviated banana-shaped foot folds against the anterolateral surface of the tibia (see Fig. 2A and B). The heel cord is stretched and abnormally long. This positional deformity should improve rapidly and spontaneously. Thoughtful parents, appropriately suspicious of your optimistic prognosis, dislike doing nothing. They should be encouraged to exercise the foot each time they change the child's diaper, stretching the dorsal tendons and ligaments. In rare cases, the foot remains severely deformed and requires corrective casts. This occurs perhaps once every 2 years in a busy pediatric orthopedic practice. The resistant case may only partially correct, appearing later as one of the subgroups with flexible flatfoot. Finally, the rare severe case must be differentiated from congenital convex pes valgus, better known as congenital vertical talus. Half of this group are associated with neurologic disorders, such as arthrogryposis or spina bifida. The vertical talus foot has a tight heel cord, whereas the calcaneovalgus foot does not. In a vertical talus foot, the hindfoot is in equinus (heel cord tight) while the forefoot is folded against the anterolateral surface of the tibia. The foot is broken down in the midfoot, with a "rocker-bottom" appearance. Metatarsus Varus (Metatarsus Adductus) The terms metatarsus varus and metatarsus adductus technically describe slightly different forefoot variations but in practice are used synonymously. The diagnostic matrix helps to clarify diagnosis: the foot can easily be dorsiflexed (heel cord is not tight) and when viewed from behind with the forefoot dorsiflexed, the heel is in valgus (deviated laterally). In contrast, a mild clubfoot cannot be dorsi flexed to neutral and the heel remains fixed in varus. A metatarsus varus deformity may be unilateral or bilateral and is probably the result of intrauterine position ("packaging" defect). Commonly, infants present with one metatarsus varus foot and the other foot in calcaneovalgus ("wind-blown feet").
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Figure 4. A, Mild bilateral metatarsus varus. B, Left foot viewed from below-note charact!"ristic kidney shape. C, The foot is easily correctible with gentle passive stretching; cast correction is not required. D, Moderately severe metatarsus varus foot. This more fixed deformity requires referral for corrective plaster casts.
As is true of all "packaging" defects, metatarsus varus feet usually improve in the first few months of extrauterine life. The initial examination should document severity: (1) mild, flexible (Fig. 4A to C); (2) moderate, fixed (Fig. 4D); (3) severe, rigid. You should also rule out associated deformities, especially hip dysplasia. The metatarsus varus foot does not require immediate referral. Instead, we recommend that the parents stretch the child's foot. The mechanically correct way to stretch a metatarsus varus foot includes firmly grasping and stabilizing the heel to avoid producing even more heel valgus. Then stretch the forefoot laterally and hold for a count of five, pushing hard enough to cause the baby to perhaps wince, but not cry. Repeat the exercise five times with each diaper change. In mild, passively correctible cases (Fig. 4A to C); the rapid improvement by age 2 months makes orthopedic referral unnecessary. Feet with moderate, fixed deformity do not correct adequately with stretching alone and remain deformed at age 2 months. Hold the child in the standing position to determine how the feet look in a weight-bearing position (Fig. 4D). This position adds the dynamic component and reproduces the severity of deformity which worries the parents. At age 2 months, these children should be referred to an orthopedic surgeon, who can evaluate the child to determine if serial corrective casts are required.
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Referral at age 2 to 4 months (at the latest) allows for cast correction while the foot is pliable. After age 6 months, cast correction is almost impossible owing to foot stiffness and vigorous kicking by the robust child. The reasons for treating these feet are controversial and treatment indications vary according to the orthopedic surgeon consulted. However, most foot specialists relate many common adult foot problems (bunions involving great toe, callosities laterally at base of fifth metatarsal) to metatarsus varus not treated in childhood. A series of three or four corrective plaster casts, applied at 1- to 2week intervals, provides rapid correction. Expert application corrects the forefoot and avoids worsening of heel valgus and the resultant tendency towards flatfoot. Corrective casts for metatarsus varus are not identical to casts for clubfoot. Ponseti's important review clarifies this issue. 2 We do not advise corrective shoes alone for treatment of metatarsus varus except cases in which the child has not been referred until age 4 to 6 months and cast correction is impossible because of stiffness and patient size. In these larger children with a bothersome residual deformity, we often resort to straight last shoes plus a Friedman counter splint (leather strap between heels to keep feet everted during sleep). These children usually have significant associated medial tibial torsion and the combination of corrective shoes plus counter splint provides some apparent improvement. We urge that children with significant metatarsus varus be referred, ideally at age 2 months and at the latest 4 months, to avoid this difficult circumstance. When a child requires corrective casts, we follow the cast treatment with straight last shoes worn full time (day and night) for 2 to 3 months to maintain the correction gained with casts. The shoes must be removed several times daily for skin inspection and for bathing. The straight last shoes are subsequently worn as a walking shoe until age 18 months. Our empiric formula has not been scientifically documented but is offered as a guideline. We do not routinely apply a Denis Browne bar to the shoes at night, since the external torque of the bar may exacerbate already present heel valgus. Finally, the extremely rigid, almost teratologic bilateral metatarsus varus includes a fixed midfoot joint deformity that will not respond to conservative treatment. These rare cases should be referred in the first few weeks of life when neonatal ligamentous laxity makes serial corrective casting easier. Some of these children will require corrective surgery, usually at age 2 to 4 years. Metatarsus Primus Varus (with Abducted Great Toe). Occasionally, infants present with only moderate metatarsus varus but maintain an extremely abducted (medially deviated) great toe, making shoe and sock donning difficult. These feet sometimes require a minor surgical release of the abductor hallucis tendon between age 6 to 18 months. The predictable cosmetic improvement pleases parents. Clubfoot (Talipes Equinovarus). As clarified in the diagnostic matrix, a clubfoot is kidney shaped and fixed in equinus, with heel varus (Fig. 5A and B). Mild cases may represent "packaging" defects; however, the more severe, fixed cases suggest "manufacturing" defects, including possible
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Figure 5. A, Typical bilateral clubfoot, viewed from below. B, Clubfoot viewed from above.
abnormal talar shape. Associated deformities should be eliminated, especially congenital hip dysplasia. In bilateral cases, we recommend a hip radiograph be performed some time during the treatment course. Possible etiologic factors (arthrogryposis, spina bifida, myotonic dystrophy, etc.) must be considered. A clubfoot requir~s immediate referral for corrective casts, applied by an interested, qualified orthopedic surgeon. Starting the correction during the first week oflife provides better correction because the infant's ligaments remain lax secondary to maternal hormones. Starting the cast correction in the neonatal nursery has some emotional appeal; however, the "technical" environment, lack of cast materials, lack of an experienced assistant to hold the foot, and so forth prevent ideal cast application. If the infant is healthy and will be discharged in a day or two, we prefer to apply the first cast within the first 3 or 4 days of life in our office or clinic, where conditions are ideal. Adhesive taping or strapping, another widely accepted method for maintaining the corrected position after manipulation of clubfoot, is not widely used by North American orthopedic surgeons. A series of four to eight casts, applied weekly, provides significant correction and is followed by shoes attached to a Denis Browne splint (or other splinting method) to maintain correction. The splint is worn full time for several months and then at night and naptime until age 1 year (or until surgical correction in severe cases). Children with more severe clubfoot deformities will require surgery some time later in the first year of life to obtain full correction. The percentage of children with clubfoot who require major surgery (posteromedial release) to complete their correction varies greatly from region to region. Some orthopedic surgeons insist on complete "anatomic" clinical and radiographic correction; thus, 75 per cent of their patients require major surgery. Others are more successful with cast correction, accepting mild residual clinical and radiographic deformity. They operate on fewer than half of their clubfoot patients.
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FLEXIBLE FLATFOOT Flexible flatfoot, an extremely common childhood disorder, becomes apparent when the child begins standing. The normal fatty tissue cloaking the infant foot often makes distinguishing a flatfoot from a slightly fat foot difficult. Most children with flexible flatfeet have loose ligaments, allowing their loose jOinted feet to sag when they bear weight (Fig. 6A). Most flatfooted "patients" come from families with loose ligaments and flatfeet (Fig. 68). Not only are their feet loose jointed, but they usually have hyperextendible knees, elbows, and fingers. If these children walked on their hands, they would also have flat hands. Initial assessment includes a review of the family history, the birth history of the child, and a brief screening examination to rule out a serious condition as a cause for the flatfoot. Have the child stand on his tiptoes (Fig. 7A and 8). If an arch forms with the foot in the tiptoe position and the heel rolls into varus (deviates medially), you can be quite certain that the child has good muscle power in the ankle and foot. Children with flexible flatfeet due to ligamentous laxity form a good arch in the tiptoe position. Clearly, a tight heel cord can produce a secondary flatfoot. We see this pattern in mild cerebral palsy (increased deep tendon reflexes), congenital tight heel cords (normal deep tendon reflexes), and muscular dystrophy.
Figure 6. A, Typical flexible flatfeet. The ankles roll medially and the child appears to be walking on the medial side of his foot. His parents and siblings also have flatfeet. B, Another loose-jointed "patient" with flatfeet. All of his relatives are similarly affiicted.
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Figure 7. A, A child with flatfoot, viewed from behind. The heels are in mild valgus. B, The same child, standing on tiptoe. Note that the heel rolls into varus and an arch is formed. Thus the child has a flexible flatfoot.
Have the child sit on the floor and then ask him to stand. This test for proximal muscle weakness (positive Gower's sign-patient uses hands on thighs to assist quadriceps) helps you to screen the Duchenne's muscular dystrophy patient who can present with flatfoot (and heel cord tightness). Occasionally, children present with a stiff, painful flatfoot that can be caused by tarsal coalition, trauma, benign or malignant bone tumors, occult infection, foreign body, Kohler's disease, and other disorders. Children with a stiff or painful flatfoot should be referred to an orthopedic surgeon for further evaluation. We do not perform routine radiographs in children with flexible flatfoot. In contrast, the child with stiff, painful flatfoot will need specific radiographs, which should be performed by the orthopedic consultant. (Note: foot pain will be presented in greater detail elsewhere in this issue.) Treatment
Flatfoot treatment indications remain controversial. Usually, the parents want their child to have "proper treatment" to avoid the flatfootedness that they endured as children. They usually wore corrective shoes in childhood and feel bound to provide similar or better treatment for their child. They assume that modern medicine would have produced a treatment method far superior to the one they had as a child. Traditionally, flatfooted children have been treated with corrective shoes including modifications intended to improve the arch (scaphoid pad). Others, particularly podiatrists, have emphasized the use of custom-molded plastic inserts worn within regular shoes. The trend for orthopedic surgeons, particularly pediatric orthopedic surgeons, has gradually evolved to not recommending corrective shoes or inserts because they are expensive, often cumbersome, and have not been demonstrated to change the natural history of flexible flatfoot. Staheli has emphasized the lack of scientific evidence for the efficacy of corrective shoes in children. 3 Recently, we completed a study of 100 children with flexible flatfoot enrolled in a prospective trial designed to compare the results of vigorous flatfoot treatment to prospective, randomized, untreated controls. 4 We were unable to document that corrective shoes or inserts had any effect on the natural history of flexible flatfoot.
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We now recommend that a child with flexible flatfoot, without significant symptoms or severe shoe wear problems, wear ordinary shoes (usually a well-fitted sneaker). We recommend special shoes only in the rare child with signifi{:!ant persistent pain or a deformity so severe that ordinary shoes wear out within a few weeks. Parents often remain unconvinced when advised that flatfoot cannot be treated, rarely understanding the somewhat esoteric concept of the natural history of a condition not being affected by intervention. Therefore, despite our advice, many parents will seek out a podiatrist or another physician who will fulfill their wish for their child to have corrective shoes or inserts.
CAVUS (HIGH-ARCHED) FEET A slightly high-arched foot and clawed great toe in infancy is a normal finqing, perhaps reflecting intrauterine position. Many older children have normal but high-arched feet, often inherited from their parents. Their feet do not require specific treatment; however, the cavus or high-arched foot leads to more shoe fitting problems than does a flatfoot. The gradual development of a cavus foot in a child may indicate a neurologic disorder (spinal dysraphism, Charcot-Marie-Tooth's disease, Friedreich's ataxia). Therefore, a child with a significant cavus foot requires a careful neurologic examination with referral to a neurologist or orthopedic . surgeon, its indicated.
TIPTOE WALKING Children often walk on their tiptoes (equinus gait), particularly during the first 2 years of walking (age 1 to 3 years). The common sporadic tiptoe gait, often a habit, requires no attention or treatment. Persistent cases can be placed in one of three categories: (1) Habitual toe walking-with the child relaxed, the foot can easily be dorsiflexed above neutral; (2) Mild cerebral palsy-deep tendon reflexes are brisk, running intensifies the deformity, the equinus cannot be completely corrected; and (3) Congenital tight heel cords (rare but definite entity)--foot cannot be dorsiflexed, even with the child relaxed (or under anesthesia). The deep tendon reflexes are normal and the child has no neurologic deficit. Careful study should clarify the pattern. Habitual toe walking should resolve with time. The cerebral palsy toe walker should be referred through usual channels for evaluation and treatment. The child with congenital tight heel cords should be referred to an orthopedic surgeon. The equinus often responds to serial corrective casts but may require surgical heel cord lengthening.
ADVICE ABOUT SHOES We currently do not prescribe corrective shoes for mild foot disorders in children, particularly flatfoot. We do recommend straight last shoes for
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maintenance of correction following serial corrective plaster casts or surgery in children with metatarsus varus or clubfoot. Mounting evidence suggesting that corrective shoes and inserts do not change the natural history of flexible flatfoot 4 supports Staheli's3 contention that children should wear a comfortable, soft shoe that fits well. In practice, this is usually a lightweight sneaker. Patients with moderate flatfoot or other foot imbalance do not get good mileage from running/jogging shoes, which currently are the most available (and socially acceptable) child's shoe. These shoes are designed for straightforward jogging or running and not for side-to-side motion (cutting sports), which rapidly destroys the shoe. Thus, a shoe fashioned after a basketball or tennis shoe (with rolled rubber edges on the sides and ends) provides greater durability and is particularly advised for children with shoe wear problems. Sandals are extremely popular and usually lightweight; however, the loose attachment of the sandal to the foot may cause the child to appear clumsy. The weight of a heavy leather "orthopedic shoe" often makes a child's gait more cumbersome, thus we recommend a lightweight shoe. Shoe modifications cannot control and correct rotational deformities such as tibial torsion or femoral anteversion and are not prescribed (alone) for these conditions. Denis Browne splints, attached to shoes and worn at night, are sometimes used to correct tibial torsion. In summary, pediatric orthopedic surgeons rarely prescribe corrective footwear. There is little evidence to suggest that cultures with fastidiously shoed children produce adults with better feet. OTHER COMMON FOOT CONDITIONS
Polydactyly Polydactyly, a relatively common autosomal dominant foot disorder, most commonly presents as an extra toe on the lateral border of the foot (Fig. 8). Occasionally, the extra digit occurs medially. A duplicated great toe, appearing as a bifid toe growing with the normal great toe, often emanates from a partially duplicted phalanx. Complex planning is required for successful surgical excision. You should refer children with polydactyly to an orthopedic surgeon at age 1 or 2 months to allow family counseling and planning for surgery. \Ve usually remove the extra digit between age 6 months and 1 year. The surgical plan becomes clearer as the child nears 1 year of age, and the cartilage and bony structures become better defined radiographically, particularly in a duplicated great toe.
Syndactyly Complex syndactyly involving multiple toes rarely occurs, and when it does we do not advise surgical separation. A partial syndactyly between the second and third toes, usually bilateral, is much more common (Fig. 9). The webbing represents a variation of normal embryologic development,
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Figure 8. Child with complex polydactyly. Both the great toe and the "fifth" toe are duplicated.
making the second and third toes appear as though they are growing from a single stalk. The underlying bones are normal. A similar deformity in the hand would be separated surgically to improve function; however, toe syndactyly rarely impedes function, thus surgical separation is not indicated. Surgical separation almost always requires skin grafting, thus the risk/benefit ratio seems excessive for a cosmetic deformity. Bunions in Adolescents Teenagers often develop a prominent first metatarsal head and radiographic findings of an increased angle between the first and second
Figure 9. An extremely common form of syndactyly (partial). No treatment is advised.
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Figure 10. Anteroposterior foot radiograph demonstrating bunions in an adolescent. The medial deviation of the first metatarsal produced a bump (bunion) at the base of the great toe. The patient was advised to wear soft shoes, which relieved her symptoms.
metatarsals (Fig. 10). In addition, the great toe deviates laterally, producing a hallux valgus or bunion deformity. The disorder is almost always bilateral. Treatment includes changing to soft, pliable shoes that accommodate the deformity. More severe deformities make boot fitting painful and difficult, particularly for figure skating, ice hockey, skiing, and other sports requiring tight boot fit. In these cases, we advise surgical correction, which includes straightening of the first metatarsal, removing the bump of bone on its medial-distal end, and tightening of the joint capsule. Most teenage bunions do not require surgery. We perform bunion surgery on adolescents perhaps once or twice a year in a busy pediatric orthopedic practice. Fortunately, there is no cutoff point after which surgery becomes more difficult. Therefore, borderline cases can be followed into adult life, with surgery advised only if pain or shoe wear problems become insurmountable. Overlapping Toes Children sometimes present with flexion deformities of the third and fourth toes, with the second toe in a more dorsal position, causing overlapping or "curly toes" (Fig. llA and B). The child then develops calluses, especially on the tip of the curled toe. Stretching and taping do not change this position; however, most children accommodate the deformity and do not require specific treatment. When the deformity is s.evere, surgical release of the flexor tendons of the curled toes corrects the toe deformity.
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Figure 11. A, Curly toes with the second toe dorsally positioned and the lateral toes excessively flexed (curled). B, Plantar view, same foot. Callosities form on the distal pads of the lateral toes. This child required flexor tenotomy of the lateral toes to relieve symptoms.
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Figure 12. Child with overlapping or cocked-up fifth toe. This annoying position often requires surgical correction.
Occasionally, children present with overactivity of the extensor tendon, producing an overlapping or cocked-up fifth toe (Fig. 12). This position makes shoe fitting difficult and the toe will not change its position without surgery. In more severe cases, we advise correction, including dorsal skin, capsule, and tendon release combined with volar skin advancement. Bony Feet Once children lose their infantile foot fat, their feet begin to exhibit their true character. Much like human hands, human feet demonstrate incredibly wide variations of normal anatomy. Parents often worry about bumps or prominences that they note on their child's feet. Inspection may demonstrate a normal but prominent "bump" over the navicular medially, calcaneus laterally, base of the metatarsals dorsally, or base of the fifth metatarsal laterally. We often look at the child's (and parent's) hands to confirm that the bony prominences are only a reflection of the child's overall somatotype. Rarely, the prominences develop an associated bursitis and produce significant symptoms (accessory navicular medially, "pump bump" on lateral calcaneus), and will require treatment. Most bony feet are best handled by first reassuring the parents that the child is normal and then recommending soft, pliable shoes.
SUMMARY
Foot deformities may reflect a generalized disorder, especially a neurologic problem; thus, the child should have a brief general examination. Many infantile foot deformities, such as calcaneovalgus, are postural and self-correcting. Metatarsus varus is not referred for treatment until age 2 months and then only if the deformity is moderate or severe. Fixed forefoot equinus and heel varus characterize a clubfoot, which requires immediate treatment.
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Corrective shoes are not advised as the primary treatment for metatarsus varus or clubfoot but often are prescribed to maintain the corrected position after serial casts. Flexible flatfoot is a manifestation of a constitutional laxity affecting all ligaments and joints. The feet appear abnormal because of weight-bearing stresses. Most children with flatfoot achieve a partial correction spontaneously. Current research does not document that treatment with corrective shoes or inserts produces a result better than the partial correction that occurs naturally. ACKNOWLEDGMENT Our special thanks to Yolanda Nerio for her help in preparing this article.
REFERENCES 1. Kurman, J. S., and MacEwen, G. D.: The incidence of hip dysplasia with metatarsus adductus. CHn. Orthop. 164:234, 1982. 2. Ponseti, I. V., and Becker, J. R.: Congenital metatarsus'adductus: The results of treatment. J. Bone Joint Surg., 48A:702, 1966. 3. Staheli, L. T.: Corrective shoes for children: A survey of current practice. Pediatrics, 66:1, 1980. 4. Wenger, D., Mauldin, D., Speck, G., et al.: The effect of treatment on outcome in flexible flatfoot: A prospective randomized trial. Unpublished data, 1985. 5. Williams, P. F.: Orthopaedic Management in Childhood. London, Blackwell Scientific Publications, 1982.
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