Chapter 213. Disorders of the Foot

A common referral to a pediatric orthopedist is for a foot deformity that may or may not be symptomatic. Conditions range from benign, self-resolving, perceived abnormalities involving the forefoot and toes, to more severe congenital and neuropathic deformities including clubfoot, congenital vertical talus, and cavus foot. Frequently, differentiation between a benign, resolving condition and a more severe pathologic deformity can be made by clinical examination and level of suspicion. A review of the common disorders, both benign and pathologic, will be presented to assist in the office evaluation of pediatric foot conditions.

Metatarsus Adductus

Medial deviation of the forefoot of an infant, termed metatarsus adductus, is one of the most common pediatric foot conditions (Fig. 213-1). Intrauterine positioning—medial rotation of the foot across the fetal torso—is the presumed cause of this positional deformity. The “deformity” is usually flexible and can be passively corrected, in which case no treatment is actually necessary. Rare cases with severe rigid deformity may require treatment.1

Clinically, the forefoot is medially deviated in relation to the hindfoot. When viewed from the plantar surface, the lateral border of the foot is curved and appears “bean shaped” (Fig. 213-1B). There may be additional medial deviation of the great toe and the appearance of a high arch.2 The deformity can be passively “corrected” if the examiner grasps the heel and maintains it in the neutral position, while abducting the forefoot (eFig. 213.1). Metatarsus adductus is almost always bilateral, although some children will demonstrate a “windswept” position of the feet, with one foot internally rotated with metatarsus adductus, and the opposite externally rotated by the intrauterine position.

Many children will present at walking age with intoeing. Metatarsus adductus is but one reason the foot progression angle can be deviated medially—the most common being internal tibial torsion (ITT). By observing the plantar surface of the foot (Fig. 213-1), the contribution to the intoeing coming from the forefoot can easily be appreciated and differentiated from ITT. Metatarsus adductus is distinguished from talipes equinovarus (clubfoot) by noting that the ankle and hindfoot have a normal range of dorsiflexion and plantarflexion, whereas a true clubfoot has a fixed hindfoot deformity (see discussion below). Rarely, the forefoot may be medially deviated in a foot that appears to have severe midfoot and hindfoot valgus, a foot that is commonly described as skewfoot (see discussion below).

Treatment of metatarsus adductus varies from observation to casting in more severe presentations.2,3 If the forefoot can be passively manipulated into a corrected position, then the parents can be instructed in passive stretching, and the “deformity” can be observed. Full resolution can be expected. Night splints or reverse-last shoes for children younger than 6 months can also be utilized, although there is little evidence that such orthotic treatment facilitates what would otherwise be spontaneous resolution. If the forefoot is not passively correctable, a short period of casting may be warranted. If using short leg casts, one must carefully insure that the heel is not pushed into valgus during the maneuver to abduct the forefoot and straighten the lateral border (eFig. 213.1).

Surgical correction is reserved for the rare patient with a fixed adductus, and symptoms. The decision for operative treatment, whether soft tissue release or bony procedures, is controversial. Orthopedic consensus is that, even with moderate fixed residual adductus, adult function is still normal.2,3

Calcaneovalgus Foot

This postural deformity of infancy is characterized by a sometimes dramatic hyperdorsiflexion position, where the dorsum of the foot is plastered to the anterior surface of the tibia (Fig. 213-2). Plantarflexion is limited, and the condition may seem severe if the contractures of the dorsal ankle structures do not allow early manipulative relief (eFig. 213.2).

The foot may also be deviated laterally, the “valgus” portion of the deformity, preventing inversion of the foot. The key is to determine whether the heel is also in dorsiflexion. If the heel has descended and moves appropriately upward when the forefoot is plantarflexed, one may conclude that this is a postural, in utero deformity, resulting as a “packaging” defect, which will resolve with time and manipulative stretching.4,5 On the other hand, if the heel has not descended with the hyperdorsiflexed forefoot or does not move appropriately when the forefoot is raised and lowered, then a congenital vertical talus must be ruled out. The latter is usually characterized by the foot having a “rocker bottom” appearance, due to the fixed equinus of the heel (see discussion below). Hip dysplasia must be ruled out in the newborn with a hyperdorsiflexed foot, because the same abnormal in utero fetal position responsible for the calcaneovalgus foot can also cause hip dysplasia.5 A less subtle deformity is a posteromedial bow of the tibia that may present concomitantly with the calcaneovalgus foot. In the latter, the tibia is deformed with an apex based posteriorly, which is easily understood as an additional packaging defect associated with the hyperdorsiflexed foot.6 However, the posteromedial bow of the tibia will require some orthopedic intervention due to the shortening of this portion of the lower extremity.

Once congenital vertical talus, posteromedial bow of the tibia, and hip dysplasia have been ruled out, then The hyperdorsiflexed foot can be treated by gentle manipulation and stretching, pushing the foot into plantarflexion (eFig. 213.2). Such stretching exercises can be taught to the parents. Inversion of the foot may also be carried out as a corrective maneuver. Typical calcaneovalgus foot will resolve spontaneously in a period of 3 to 6 months, although occasionally a more severe case may be referred to the orthopedist for either splinting or casting. Parents should be educated as to the benign nature of this deformity, but they should also be warned that there may be a flatfoot appearance when ambulation begins.

Flexible Flatfoot (Pes Planovalgus)

Flatfoot is probably the most common “deformity” evaluated by pediatric orthopedists. Whether it constitutes an actual deformity is, in fact, questionable.7 In general, the weight of the child’s body in the presence of lax ligaments in the foot flattens the normal arch. In the infant and pretoddler child, a “fat” foot should not be mistaken for a flatfoot, as the arches of infants and young children are often obscured by subcutaneous fat.8 Finally, a lower arch is a normal variant. It is thus surprising that flatfoot is evaluated and treated, often prophylactically by nonorthopedic branches of medicine, fearing that the loss of the longitudinal arch, however subjective, will result in symptomatic disability.

There is no universally accepted definition of flatfoot. The normal height of the longitudinal arch is unknown, and radiographic analysis of the foot is rarely indicated if the physical examination does not reveal a specific indication (see discussion below). The appearance of a flatfoot is well known—the heel is everted with a loss of height, and the talar head and navicular appear to rest on the floor medially. The medial column of the foot may appear longer than the lateral column. When viewed from behind, the examiner may note that all five toes are visible to the lateral side of the tibia (called “too many toes” sign) (eFig. 213.3). However, while observing the child from behind, the examiner may request that the child go up on tiptoes, at which time in the flexible flatfoot, the longitudinal arch will reconstitute, and the heels will invert (eFig. 213.3C). This simple maneuver basically rules out any significant congenital foot pathology. When examining the foot with the child seated and the foot dangling, the flexible flatfoot will demonstrate ease of inversion and eversion, and again the longitudinal arch will be seen to reconstitute.

The differential diagnosis of flatfoot includes conditions such as congenital vertical talus, in which the heel is in equinus and will not correct, and tarsal coalition, in which there is marked restriction of subtalar and midfoot movement, most easily detected by the tiptoes test just described. Tarsal coalition usually presents in older children, typically because of pain.

A decreased longitudinal arch has been described in as much as a quarter of the adult population, and thus must be considered a normal variant. This, however, does not remove the possibility that the patient may have symptoms, which are almost always associated with a contracture of the triceps surae9 and can be detected by dorsiflexion of the foot with the heel stabilized in neutral and the knee fully extended. Patients with a tight triceps complex tend to have more complaints from their flexible flatfeet. Should heelcord contracture be suspected, the child should be asked to walk on his or her heels, which will be difficult with a significant contracture.

Treatment of flexible pes planovalgus depends on the presence or absence of symptoms. Asymptomatic flatfeet require no treatment, with education and reassurance being given to the parents. There is no evidence that prophylactic treatment of flexible pes planovalgus prevents either the development of symptoms or the progression of a deformity.10,11

In symptomatic patients, a variety of shoe inserts, shoe modifications, and exercises are available. If the child has a tight heel cord, then exercises to stretch the gastrocsoleus complex are indicated (eFig. 213.4). The most effective exercise is the gentle dorsiflexion of the foot with the heel stabilized in neutral and the knee in full extension. Calf muscle stretching by leaning forward with the feet inverted, knees extended, and hands on a wall is also recommended (eFig. 213.4). For heel eversion, a medial heel wedge attached to the sole of a shoe may be useful, and with more symptomatic feet, the use of a soft or rigid insert to invert the heel and support the longitudinal arch are often considered (eFig. 213.5). There is no evidence, however, that any of these corrective devices change the anatomic structure of the foot. In light of the not-insubstantial costs of some of the custom-molded orthotics, there is little justification for prescribing such devices unless symptoms warrant. Perhaps the most effective shoe modification for the child with painful flexible pes planovalgus is the recommendation to purchase “running shoes” from an athletic store. Such running shoes, often prescribed for “hyperpronated feet,” include most of the modifications, such as a medial heel wedge, arch support, and rigid heel cup, which are normally prescribed by physicians and gladly provided by orthotists. The use of such running shoes makes prescription of these additional orthoses unnecessary.

There are occasionally older adolescents whose hypermobile flatfoot continues with intractable symptoms in spite of stretching exercises and shoe and orthotic prescriptions. Such patients are rare and represent the only true candidates for surgical management. Because many of the surgical procedures for hypermobile flatfoot are often unsatisfactory in long-term outcomes, pediatric orthopedists are reluctant to recommend such treatment except in the most dire of circumstances. In order to change the anatomic position of a hypermobile flatfoot, some form of stiffening of the joints of the foot—either by imbrication, osteotomy, or fusion—must be applied to the foot. Although short-term efficacy is to be expected, longer-term studies report unsatisfactory results from such surgery,12-14 because all of these stiffening maneuvers will result eventually in osteoarthritic changes within the foot at the adjacent unfused joints. For this reason, only the most recalcitrant of hypermobile flatfoot is ever considered for surgical correction.

Skewfoot

This rare deformity resembles metatarsus adductus but also has the elements of hindfoot valgus and is usually more rigid and severe than any metatarsus adductus alone (eFig. 213.6). Skewfoot has also been termed serpentine or Z-foot, based on the radiographic deformity (eFig. 213.6). Patients will usually present because of discomfort under the base of the fifth metatarsal or under the head of the talus on the medial side. The rigidity of the skewfoot is the striking difference between its relatives, simple metatarsus adductus or simple hypermobile flatfoot.

Patients usually present in older childhood or adolescence when pain and complaints become more severe.15 Because of the later presentation and rigidity, nonoperative methods are rarely successful. Operative treatment may be indicated if symptoms warrant and is often complex due to the rigid deformities at multiple points from the heel to the forefoot.

Clubfoot (Talipes Equinovarus)

Clubfoot is probably the best-known pediatric foot condition requiring treatment, having been known since ancient times. It represents congenital dysplasia of all musculoskeletal tissues distal to the knee and is present in 1 to 2 per 1000 live births. Ancient practitioners struggled with producing an acceptable outcome for clubfoot just as modern orthopedists do because of the myriad of pathologic findings that prevent an optimal outcome from being achieved. Regardless of whether a clubfoot is corrected nonoperatively or operatively, there always appears to be some degree of impairment in the function of the extremity, due to restricted motion in the ankle and hindfoot, diminished muscle strength and power generation of the triceps surae, and kinetic and kinematic abnormalities related to atrophy and fibrosisof the musculoskeletal tissues below the knee. Clubfoot is a congenital abnormality that begins developing prior to the 12th week of gestation; thus, by the time the infant is born, the congenital dysplasia of the lower limb has been present for up to 7 months of intrauterine life.16,17

Evidence of such dysplasia is noted when one looks, for example, at the severely dysmorphic bones of the fetal clubfoot (eFig. 213.7). This difference, combined with the soft tissue fibrosis that impairs manipulative correction, defines why clubfoot is a serious congenital anomaly. Modern treatment, which has returned to an emphasis on nonoperative methods, seeks early anatomic correction while at the same time providing as much motion as possible to counteract atrophy and muscle weakness. Clinical identification of the clubfoot is rarely difficult. The classic appearance of the heel in marked equinus with the foot severely inverted on the end of the tibia is unmistakable (Fig. 213-3). The foot may approach a position of being upside down in relation to the normal position. Lack of correctability of the inversion and the heel equinus separates the true clubfoot from a more mild postural deformity. At the time a newborn infant with a clubfoot is evaluated, Other associated syndromes or conditions, such as Down syndrome, arthrogryposis (eFig. 213.8), skeletal dysplasias, spina bifida or spinal dysraphism, or other trisomy and dysmorphic conditions should be kept in mind. Although concomitant dysplasia is reported to occur in less than 1% of patients with idiopathic clubfeet, a screening hip examination should always be done.

The infant with a clubfoot should be referred quickly, as it is generally agreed that the earlier treatment is begun, the more likely that nonoperative methods will be successful. This is due to the relatively viscoelastic character of the newborn foot, which rapidly becomes nonelastic if treatment is delayed beyond the age of 3 months. Nonoperative treatment has become the mainstay because of the clearly unsatisfactory long-term results obtained with surgery, based on many studies demonstrating that surgically treated feet are stiffer and weaker, due to scarring and muscle atrophy.18,19 Nonoperative treatment proposes to gradually correct the clubfoot deformity without producing the scar tissue that inevitably diminishes the result.

Two methods of nonoperative treatment are currently employed. The first is serial casting, described and popularized by Ponseti of the University of Iowa.20 This method, which involves weekly manipulation and cast application, proposes to correct the foot and allow relaxation of the collagen and remodeling of the osseous structures without producing fibrosis and scarring. The technique is usually spread out over 4 or 5 cast applications done weekly (Fig. 213-4), with a percutaneous heel-cord release done prior to the final cast to bring the foot out of equinus, commonly the most recalcitrant of the four major deformities (cavus, adductus, varus, equinus) that characterize a clubfoot. The retention of the corrected position by a long-leg cast is an important aspect of the Ponseti method, as is the percutaneous heel-cord prior to the final casting Over the 5 weeks of casting, the foot is gradually brought out of cavus and externally rotated, with the dorsiflexion of the foot being the final maneuver assisted by the percutaneous TAL (tendoachilles lengthening). A certain degree of “overcorrection” is sought by the final cast so as to ensure full derotation and correction of the initial cavus, adduction, and varus (Fig. 213-4). Following removal of the last cast, an equally important period begins of bracing the foot in the corrected position by the use of a Denis Browne bar attached to shoes which maintains the feet in 50 to 70 degrees of external rotation (eFig. 213.9). The orthosis is worn full time for a period of 4 months, and then part time for up to 2 years to maintain the correction.

The results of the Ponseti technique have generally been favorable, with 90% of patients undergoing early treatment avoiding surgery20 (the percutaneous TAL is not considered a surgical procedure as it is part of the initial protocol). The avoidance of early surgical procedures is one of the great advantages of the Ponseti method, and long-term outcomes document that by physical examination over half the feet are considered “normal,” although there are both motion and radiographic changes that characterize the residual of any clubfoot. It must be realized, however, that relapses of corrected clubfeet with the Ponseti method are relatively common, requiring additional casting, limited surgical releases, or tendon transfers in order to obtain correction over the longer term. Most studies, however, report a high degree of success with Ponseti’s method despite recurrences reported for up to one third of the patients.

The second nonoperative method is termed the functional or French method, having been developed in Europe, primarily by French orthopedists, in the 1980s.21 The method is considered functional because the foot is stretched daily by trained physiotherapists, with the correction being maintained overnight by a method of taping. The passive manipulations are combined with active stimulation of dorsiflexors and peroneal muscles for a period of 2 to 6 months. Nighttime splinting for up to 2 to 3 years follows.

The French method became known in the United States in the 1990s. Its primary deficiency is the fact that trained physical therapists are necessary for it to succeed, and it is considerably more time consuming than the weekly castings of the Ponseti method. Cooperation and transportation of families is essential for such a program to work, and obviously, patients who live a long distance from the treatment center cannot participate successfully. Nevertheless, in patients able to undergo the French method, similar results have been obtained in the short term, with surgical releases generally being avoided in the first year of life.21 Posterior release, however, is frequently required, because the equinus deformity is not addressed surgically until the child begins ambulation.22 Residual equinus, the most resistant of the clubfoot components, may not be adequately corrected except by percutaneous TAL or posterior release, frequently delayed until ambulatory age.

Surgical correction is appropriate for a foot that is resistant to nonoperative methods. Although many orthopedists believe that surgery is the only method to completely correct a severe clubfoot, the long-term outcome of the surgically treated feet, critically reviewed in the 1990s by several investigators,18,19 demonstrates that multiple operations are common but need to be avoided, and that recurrence is almost always due to incomplete correction. The stiffness and atrophy as well as scarring from operative procedures leave no doubt that surgery for clubfoot should not be the primary choice.

Typically surgery is performed around walking age in the patient who has failed nonoperative methods early due to intolerance of casting, intolerance of posttreatment bracing (DB bar), or noncompliance with either of the nonoperative protocols. There is no advantage to performing surgery earlier than walking age, because the ability to be fully weight-bearing in the postoperative period may in fact be of great assistance in maintaining correction by encouraging a plantigrade foot with no equinus. Soft tissue releases are recommended as the first approach at this age and include extensive ligament and tendon releases and lengthenings, from the posterolateral corner of the ankle and subtalar joint to the medial side of the midfoot. The extent of the procedure must be evaluated intraoperatively in order to ensure that both under- and overcorrection are avoided. As mentioned earlier, although undercorrection is most frequently the cause of “relapse” and leads to repeated surgical procedures, overcorrection into excessive valgus and dorsiflexion can also occur, with debilitating long-term functional implications. The surgeon who is the first to operate on a congenital clubfoot bears a great responsibility in that subsequent operative procedures will almost certainly be regarded as salvage, and whatever improvement in anatomic position that is achieved will almost undoubtedly be accompanied by functional disability due to weakness and stiffness.18,19

Congenital clubfoot remains a treatable but somewhat unsolved problem in pediatric orthopedics. The outcome of treatment depends significantly on the severity of the deformity at presentation, as well as the timeliness and competence of the nonoperative treatment. Competence and timeliness notwithstanding, success also depends significantly on the compliance of the family in maintaining the corrected foot in an appropriate orthosis until walking age, with timely limited surgery being appropriate if there is residual deformity or recurrence following the initial nonoperative method of infancy.

Congenital Vertical Talus

Congenital vertical talus (CVT), also known as congenital convex pes valgus, is a rare foot anomaly, typically differentiated from clubfoot by the appearance of the foot resembling a rocker-bottom deformity (Fig. 213-5). The pathology in CVT is a teratologic dorsal dislocation of the talonavicular joint, in which the midfoot and subtalar joints are dislocated dorsally and laterally while the heel is still fixed in equinus (Fig. 213-5B). In a sense, the reverse of the inverted cavus deformity represents clubfoot.

CVT often presents in association with arthrogryposis or myelomeningocele and various trisomy syndromes. In fact, idiopathic vertical talus is a relatively rare entity, so the patient presenting with a true convex pes valgus must be evaluated for a generalized condition or syndrome.

Clinically the foot has a rocker-bottom appearance, due to the heel being in equinus, combined with the talar head presenting itself in the medial plantar sole of the foot (Fig. 213-5). The forefoot is everted and dorsiflexed and cannot be inverted, due to the contracture of the soft tissues of the dorsum and lateral aspect of the ankle. The navicular is palpable on the dorsum of the talar neck.

A lesser degree of severity may manifest itself as an oblique talus. In this situation, the dorsilateral structures of the ankle are not as severely contracted, and the navicular can be reduced onto the head of talus when the forefoot is plantarflexed and inverted. The heel remains in some degree of equinus.23 This feature—the residual equinus of the calcaneus—and the resulting plantarflexion of the talus describe the radiographic appearance on the lateral X-ray which gives the condition its name—the talus is vertical and parallel to the longitudinal axis of the tibia (eFig. 213.10). Any foot of a newborn or young child which has heel equinus, a rocker-bottom appearance, and lack of inversion and plantarflexion should be suspected of having CVT.

Differential diagnosis for CVT includes a calcaneo-valgus foot. The latter deformity is not easily confused when the heel is seen to descend appropriately when the foot is dorsiflexed. At walking age, a severe flatfoot with a heel-cord contracture may also be mistaken for a vertical talus. This is differentiated by the fact that flatfoot can be inverted and plantarflexed, with the navicular reducing on the head of the talus, and whatever valgus is seen in the flatfoot can also be corrected by inversion. No such flexibility occurs with CVT. Obviously, if any doubt remains following clinical evaluation, a lateral radiograph of the foot in plantarflexion will settle the issue (eFig. 213.10).

Treatment of the congenital vertical talus includes early casting in an attempt to stretch the contracted dorsilateral structures and reduce the navicular on the talus, followed by operative open reduction of the talonavicular joint and release of the hindfoot equinus. The procedure is similar in many ways to the clubfoot release and can be done at any age from immediately prewalker to mid-childhood, depending on the time of recognition of the deformity. The results tend to be better in children under the age of 2, and older children usually require some form of joint stabilization by arthrodesis in order to prevent recurrence.24 Long-term functional outcome of CVT is uncertain, because most patients with CVT have various disabilities and low functional demands due to comorbidities associated with their underlying syndrome or chromosomal abnormality.

Tarsal Coalition

This condition usually presents as a painful flatfoot. By definition, there is an abnormal lack of segmentation between two or more bones of the foot, and this accounts for the rigidity and pain that bring the patient for evaluation.25,26 Because of the rigidity and appearance of the foot, the condition is also known as peroneal spastic flatfoot.

Patients typically present between the ages of 12 and 16 years, although some coalitions have been documented in children as young as 6 years.27 Pain is almost always the initial complaint and is often located in the tarsal sinus, though it may also be present under the medial malleolus and along the arch of the foot. Pain is often activity related, and patients may notice a progressive external rotation and flatfoot, the latter being responsible for the medial arch discomfort.

The predominant physical finding is decreased range of motion at the subtalar joint, best demonstrated by lack of inversion. Patients are often unable to stand on tiptoes without discomfort, and there is a noticeable lack of inversion of the heel when the tiptoe position is requested. This is in contradistinction to the physical findings of a flexible flatfoot. The hindfoot may be in significant valgus as well, and the resistance to passive inversion is often attributed to spasticity of the peroneal tendons—hence, peroneal spastic flatfoot.

The diagnosis should be suspected in any adolescent with painful flatfeet and restricted inversion. Plain radiographs should include anteroposterior (AP), lateral, and oblique views. A calcaneonavicular coalition, the most common tarsal coalition, is usually readily apparent on the oblique x-ray (eFig. 213.11). On the lateral x-ray, secondary changes suggestive of medial facet talocalcaneal coalition (eFig. 213.11B) include talar beaking and the “C” sign, a crescentic bony ridge underneath the talocalcaneal joint. True visualization of a medial facet coalition usually requires a computerized tomography (CT) scan (eFig. 213.11) with the appropriate coronal plane cuts across the subtalar joint (eFig. 213.11C). Coalitions involving other foot joints, including talonavicular, calcaneocuboid, and others, are rare but can usually be recognized on plain radiographs of the feet.

The differential diagnosis of painful rigid flatfeet includes inflammatory processes involving the subtalar joint, as with pauciarticular juvenile arthritis. A difficult clinical problem is the patient with classic symptoms and findings of a tarsal coalition but in whom no coalition can be identified radiographically. Occasionally fibrous coalitions are found, but surgical treatment of such cases frequently is ineffective or the patient develops recurrence.

Treatment of tarsal coalition, documented radiographically or suspected, should be conservative initially, including the use of orthoses, a short period of casting, and injection of the involved subtalar joint with a combination of local anesthetic and steroid. The latter serves both as a diagnostic as well as a therapeutic modality, with some patients receiving long-term relief of the pain for reasons that are not known. but presumably have to do with decreasing the inflammatory response produced either by the abnormal subtalar motion or an intra-articular pain generator. Patients who fail conservative treatment with documented coalitions are then candidates for either resection of the coalition or subtalar midfoot arthrodesis. A calcaneonavicular coalition is easily excised, and the defect created by the excision is filled with subcutaneous fat taken locally from the same lower leg. A medial facet talocalcaneal coalition is more difficult to resect, with subsequent motion more difficult to achieve. If the coalition is not completely removed, the abnormal subtalar motion will continue. Most authors report success resecting calcaneonavicular coalitions, but talocalcaneal coalitions are more unpredictable.28,29 Large coalitions, as well as average size coalitions in obese patients, seem to be most likely to fail. In the latter circumstance, the presence of a large medial facet coalition may best be treated by subtalar fusion rather than an attempt at resection. The best treatment for medial facet coalitions remains controversial.

Cavus Foot

The cavus foot is defined by an abnormal elevation of the longitudinal arch. The deformity has complex underlying etiologies and consists of both forefoot equinus and varus as well as pronation of the midfoot. The etiology of pes cavus is often neurologic,30,31 with the most common underlying diagnoses being peripheral neuropathies such as Charcot Marie Tooth disease and tethered spinal cord. Other diagnoses include cerebral palsy, poliomyelitis, Friedrich’s ataxia, and myelomeningocele. Idiopathic pes cavus exists but must be made as a diagnosis of exclusion.

The clinical features of a cavus foot include plantarflexion of the forefoot with a high arch, with some degree of varus of the hindfoot and pronation of the first metatarsal (eFig. 213.12). The latter deformity produces an inversion and varus of the entire foot by the tripod effect32 (eFig. 213.12), as the plantar surface of the first metatarsal is the first portion of the foot to strike the ground during weight bearing, then producing an inversion of the entire foot and varus of the heel. Patients typically present because of pain under the lateral aspect of the foot due to excessive weight bearing, as well as complaints of frequent lateral ankle sprains due to the forced inversion in association with whatever muscle imbalance or weakness is present from the neuropathic etiology.

The clinical deformity may be fairly mild, if the primary deformity is only a high arch. Inversion of both the forefoot and hindfoot usually produce callosities or pain under the lateral border of the foot due to the abnormal weight bearing in a more advanced case (eFig. 213.13). Secondary changes, again due to the progression of neuropathic changes, include cock-up and clawing deformities of the toes (eFig. 213.14). Determining the underlying etiology of a cavus foot is the first priority because of possible treatment of conditions involving the spinal cord (including tumors) or the underlying neurologic condition. Conservative measures to relieve the abnormal weight bearing and ankle instability include orthoses to balance the weight-bearing surface of the foot or ankle–foot orthoses (AFOs) to stabilize the ankle, and in the case of a muscle weakness etiology, assist with dorsiflexion. Such methods may be quite efficacious but frequently due to progression of the neuropathic condition, the foot deformity progresses to require surgical stabilization.

Surgical procedures to correct a cavus deformity are as numerous as there are underlying etiologies producing it. Depending on the etiology and the severity of the neural imbalance, such procedures as plantar fasciotomy, osteotomy of the first metatarsal and calcaneus, or midfoot osteotomy may be required alone or in combination to create a plantigrade foot with a decreased longitudinal arch and removal of hindfoot varus, thus stabilizing the ankle.32,33 In recurrent or more progressive cases, some form of hindfoot and midfoot arthrodesis, with or without first metatarsal osteotomy to dorsiflex the forefoot equinus, is often required. The surgical goal is to provide stable plantigrade feet that do not require bracing unless the patient also has a foot drop due to weakness of the tibialis anterior muscle.

Hallux Valgus (Bunion)

Hallux valgus in a pediatric orthopedic practice is usually seen in adolescent females who are concerned about cosmesis as well as pain. A positive family history is present in up to three quarters of the patients, and the concern becomes more significant as the child enters adolescence. The deformity consists of lateral deviation of the great toe, with the apex at the first metatarsophalangeal joint (Fig. 213-6). The prominence of the head of the first metatarsal is usually responsible for the discomfort, but the lateral deviation with under- or overlapping of the second toe produces the cosmetic concern. Patients with hallux valgus usually have a rather wide forefoot, making narrow “fashionable” shoes difficult if not impossible to don (eFig. 213.15).

Occasionally, there is an underlying condition associated with the hallux valgus, which may be mild cerebral palsy or connective tissue conditions such as Marfan syndrome or Ehlers-Danlos syndrome. There is controversy whether a flexible flatfoot can actually lead to hallux valgus, as well as the likelihood of recurrence of a hallux valgus deformity in the patient with an uncorrected or untreated flatfoot.34,35

Pediatric patients with hallux valgus should initially be strongly encouraged to avoid surgical treatment. Surgical procedures to straighten the deformity are fraught with untoward effects and complications, not the least of which is recurrence if the patient is skeletally immature or has a significant flexible flatfoot.34,35 Because most procedures involve imbrication of the first metatarsal-phalangeal joint to help maintain correction of the deformity, a certain degree of stiffness will be imparted to this joint, which may impact athletic activities such as running, as well as be the precursor for degenerative arthritis. Unfortunately, the latter can occur in the untreated hallux valgus, and thus there is no consensus on the value of prophylactic correction in adolescents.

If the patient is skeletally immature, surgery should be delayed until maturity, as the risk of recurrence is exceptionally high in younger patients.35 Treatments such as night bracing and stretching exercises of the great toe have value, although there is no evidence that this will provide a long-term solution. Toe spacers and other splints can be tried and may have short-term benefit but again eventually will be unsatisfactory. In patients with pes planovalgus, an arch support and other shoe inserts to decrease the valgus pressure on the great toe are appropriate.

Surgical treatment for the mature adolescent is similar to the treatment for the adult, in that a combination of osteotomies, soft tissue releases, and capsular imbrication are usually used (eFig. 213.15). The indications for the various osteotomies, as well as other adjunctive procedures to displace the great toe dorsally or medially, are sources of orthopedic controversy yet to be resolved. In failed hallux valgus surgery, the final common procedure is a metatarsal-phalangeal fusion, often considered an unsatisfactory outcome because it sacrifices the important function of the great toe during running and push-off.

Polydactyly

Extra toes are probably the most common congenital toe deformities noted, with an incidence of almost 2 per 1000 live births. A positive family history is present in one third of the patients, with the fifth toe being the most frequently duplicated (postaxial polydactyly) (eFig. 213.16).36 Duplication of the fifth toe probably accounts for 80% of the cases of polydactyly of the foot. Preaxial (duplication of the great toe) is less common (eFig. 213.16C) and is seen in association with syndromes including trisomy-13, tibial hemimelia, and Down syndrome.

Removal of a duplicated fifth toe can be accomplished at essentially any time but is probably best done around walking age. This allows the toes to enlarge to a point where the surgery is technically simple due to ample skin and soft tissue for coverage. An important aspect of this waiting is also to make the risk of anesthesia less severe than it would be if the surgery were done in a newborn. For duplication of the great toe, general guidelines for when surgery should be attempted are more difficult, because the variety of duplications vary from simple to complex, and some consideration for no treatment should be made if the deformity is not significantly bulky and, as in most cases, the function is nondisturbed. In cases, however, where there is deformity associated with the duplication (eFig. 213.16C), surgical treatment is appropriate when the child begins ambulating and shoe wear becomes an issue.