Foot Problems



Foot Problems


Kenneth J. Noonan, MD, MHCDS

VINCENT S. MOSCA, MD

Todd A. Milbrandt, MD1


1Guru:








How some parents seem to see their children. (Adapted from Wenger DR, Rang M, eds. The Art and Practice of Children’s Orthopaedics. New York, NY: Raven Press; 1993.)



Clubfoot

While an entire book can be written on clubfoot, we will just stick to a limited number of pitfalls. Clubfoot is frequently part of an underlying syndrome, thus a complete history and physical examination is warranted to uncover other abnormalities. Clubfoot is also associated with tarsal coalition tibia and fibular hemimelia.1 There is no indication for pelvis radiographs, as there is no known association between clubfoot and developmental dysplasia of the hip (DDH).2 Regardless, all children being evaluated for musculoskeletal problems should have a careful hip examination; parents love it when you “check under the hood.” Imaging of hips should be based purely on risk factors or findings suggestive of DDH.


All clubfeet will benefit from initial treatment with the Ponseti method, a series of manipulations and cast applications, which, when combined with a heel cord tenotomy, provides initial correction of the idiopathic clubfoot in up to 95% of patients.3 Even children with syndromic clubfeet (who have a higher rate of residual deformity) will have some improvement in their deformity. Some practitioners have very good success with the Ponseti method in these feet, and they cite the need to go slow in these stiff feet and the need for many more casts than is usual in idiopathic clubfeet. In our opinion, the main pitfalls in use of the Ponseti method result from deviation from the prescribed technique as described by the originator.4





Some clubfeet can develop a “complex clubfoot” pattern during the Ponseti method. When wondering if the foot you’re treating is developing this pattern, think reflex sympathetic dystrophy. Besides retraction of the great toe and full plantar crease as described by Ponseti; if the foot is red, very swollen, and the child absolutely hates to have the foot touched (reflex sympathetic dystrophy-like symptoms) you are likely dealing with a complex
clubfoot pattern (Fig. 29-3). In these cases, the best thing to do is to stop treatment. Give the child a few weeks’ break and start again; albeit more slowly. ORTHOPAEDICS 101: Don’t apply the cast beyond the degree obtained with manipulation.






Figure 29-1 This 9-month-old girl with arthrogryposis has developed a pressure sore over her talus head from a Ponseti cast. KEY POINT: In stiff feet go slow; in all feet don’t cast the foot beyond what is obtained during manipulation. (Used with the permission of the University of Wisconsin Division of Pediatric Orthopaedics.)






Figure 29-2 Tenotomy locations.






Figure 29-3 A: A complex clubfoot is diagnosed when the foot becomes swollen and red and is very irritated. B: The great toe is retracted and a full plantar crease is seen. (Used with the permission of the University of Wisconsin Division of Pediatric Orthopaedics.)

With the Ponseti method, over 98% of clubfeet will have good initial correction and will not need extensive posterior medial release. Over time, recurrent or residual deformity in clubfeet can be present in up to a third of patients. Repeat serial casting should be performed for these feet. If full deformity correction cannot be obtained, an ala carte approach to surgical correction is taken in these feet. For instance, posterior contracture can be managed with a repeat tenotomy, open Achilles lengthening, or even posterior release of the ankle joint. Dynamic forefoot supination is best managed with an anterior tibialis transfer to the lateral cuneiform.

During clubfoot surgery for residual or recurrent deformity, preservation of vascular supply should be the number one priority. Absence or a substantial reduction in the size and flow of the anterior tibial artery occurs in approximately 90% of limbs with clubfoot. Preservation of the posterior tibial artery should be a surgeon’s number one priority. One should consider not fully exsanguinating the foot prior to tourniquet inflation in order to visualize the posterior tibial neurovascular bundle. Although uncommon, the posterior tibial artery may be absent in a clubfoot.9 If the posterior tibial vascular bundle cannot be located at the time of surgery, even after the tourniquet is taken down, a hypertrophied peroneal vascular bundle may be present and should be carefully protected.


Metatarsus Adductus

It is hard to get in trouble with this condition as long as you make the right diagnosis and don’t treat it. First, make certain there is normal ankle dorsiflexion; if not, it is not metatarsus adductus (MTA) and may be a clubfoot. Look at the hindfoot; if there is significant valgus, think of a skewfoot (Fig. 29-4). It may be difficult to differentiate between MTA and skewfoot with radiographs in infants as the navicular is not yet ossified (Fig. 29-5). MTA may also be confused with a metatarsal longitudinal epiphyseal bracket (Fig. 29-6).







Figure 29-4 This child has bilateral foot deformities. A: Viewed from the top, he has bilateral metatarsus adductus in which the left is worse than the right. B: From behind, the child has severe hindfoot valgus. This child must have a skewfoot or variant as children with metatarsus adductus have a normal hindfoot.






Figure 29-5 Serial radiographs of the less involved right foot from Figure 29-4 confirm that this is a classic skewfoot. The initial radiographs at presentation (A) are inconclusive and could be metatarsus adductus or skew foot. B: With time and further development, it becomes clear the navicular is laterally displaced (arrow) on the head of the talus and the forefoot is adducted on the midfoot. In combination with hind foot valgus, this is considered a skewfoot.






Figure 29-6 A: The presenting picture demonstrates that the left foot has severe asymmetric metatarsus adductus of the first ray. B: Radiograph of the left foot reveals the child has a bracket epiphysis (arrows) of the first ray. Most practitioners would recommend resection of the medial aspect of the growth plate.


In the extraordinarily unlikely event that surgery is needed for MTA, do not do a capsular release as this leads to poor results. We recommend an osteotomy of the medial cuneiform, rather than the first metatarsal, both to avoid the proximal physis of the first metatarsal, and for better correction. Lateral osteotomies may be of the second to fifth metatarsals or the cuboid.






Figure 29-7 Calcaneal valgus in a newborn. It is not unusual for the dorsum of the foot to be touching the leg anterior to the tibia.


Positional Calcaneovalgus

This is a very common deformity in newborns. Although the appearance of the foot may be striking and can be confused with congenital vertical talus, spontaneous correction is the rule (Fig. 29-7). Having the parents perform stretching exercises may help the babies a little, but it can help the parents a lot and will keep the grandparents happy that something is being done. “Apparent calcaneal valgus feet” may in fact be posterior medial bowing of the tibia, which usually corrects spontaneously but may result in a 3- to 6-cm leg length discrepancy at maturity.


Congenital Vertical Talus

Congenital vertical talus (CVT) is an uncommon foot deformity in young infants and may not be quite as obvious as some other foot deformities. CVT is characterized by a flat everted foot, which, in some respects, has the opposite appearance of a clubfoot, in which the foot is in cavus and inversion. Both deformities have Achilles tendon contractures. In the clubfoot, the equinus deformity is obvious. In CVT, the ankle doesn’t appear to be in equinus because of the dorsiflexion contracture of the anterior/dorsal structures. This results in a midfoot breech with a rocker bottom and plantar prominence of the talar head (makes foot look flat). To stay out of trouble, the provider has to do three things:



  • Confirm the diagnosis of CVT in contradistinction to an oblique talus, positional calcaneovalgus, posteromedial bowing of the tibia, or is just a really flat foot (Fig. 29-8).


  • Determine whether the child with CVT has one of the associated diagnoses that are present in 50% of patients. (Consider genetics and neurology consults.)


  • Treat the CVT foot with Dobbs method of correction.

By definition, CVT is a fixed dorsal dislocation of the navicular on the head of the talus. As the navicular is not ossified until about 3 years of age, and cannot be seen on plain radiographs, we rely on the relationship of the axis of the talus and the first metatarsal. The diagnosis is confirmed on the plantar flexed lateral radiograph by observing that the axis of the talus passes plantar to that of the first metatarsal (Fig. 29-8B and C). Avoid the pitfall of believing that if the two axes become parallel,
there is no vertical talus. Dorsal translation of the first metatarsal axis in relation to that of the talus indicates dorsal dislocation at the talonavicular joint (Fig. 29-9). The axis of the talus remains vertically aligned with the axis of the tibia on the dorsiflexion lateral radiograph. An oblique talus is on the spectrum between flat foot and CVT; consider it a CVT without a lot of anterior contracture and without dislocation of the navicular. It is characterized by incomplete dorsiflexion of the talus in the ankle mortice, as seen on the dorsiflexion lateral view (normal is 90°) (Fig. 29-10A). There is fair alignment of the talus and first metatarsal on the plantar flexion lateral radiograph (Fig. 29-10B). The exact definition of an oblique talus is debated, but stretching and heel cord tenotomy may be effective.






Figure 29-8 Three-month-old with vertical talus. A: Rocker bottom medial prominence characteristic of vertical talus. B: Lateral radiograph of foot is nondiagnostic. Although the axis of the talus is plantar to that of the first metatarsal, this radiograph is consistent with an oblique talus as well as vertical talus. C: Lateral radiograph in forced plantarflexion confirms the diagnosis of vertical talus as the axis of the talus and first metatarsal still do not line up and the talus remains quite vertical relative to the first metatarsal.






Figure 29-9 Example of a child with vertical talus (A) in which the axes of the talus and first metatarsal become nearly parallel in plantar flexion (B), but the axis of the first metatarsal is translated dorsal to that of the talus. Recall that the definition of a vertical talus is a fixed, dorsal dislocation of the navicular relative to the talus to help understand why this radiograph is consistent with a vertical talus.






Figure 29-10 A: Child with an oblique talus. Note that this radiograph shows a quite similar relationship between the talus and first metatarsal as that seen in Figure 29-9. B: With plantar flexion, the axis of the talus and first metatarsal significantly change their relationship.







Figure 29-11 Dobbs method of manipulation in congenital vertical talus. The thumb of one hand is placed on the head of the talus for counterpressure while the other hand gently stretches the foot into plantar flexion and inversion. The heel should not be touched, so as to allow the calcaneus to slide from a valgus to a varus position under the talus. (From Dobbs MB, Purcell DB, Nunley R, Morcuende JA. Early results of a new method of treatment for idiopathic congenital vertical talus: surgical technique. J Bone Joint Surg Am. 2007;89(suppl 2, Pt 1):111-121.)


Clubfeet and CVT are different in shape, and patients with CVT are also more likely to have an associated condition; yet historically, they both share a similar evolution toward nonoperative treatment. In the past, the CVT foot was treated with extensive surgical release just as clubfeet were treated with wide posterior medial release. Ponseti developed his nonoperative method of treatment for clubfoot, and it is no small coincidence that one of his protégés, Dr. Matt Dobbs, developed a similar approach for CVT. With his method, the foot is manipulated by plantar flexing and inverting the forefoot against plantar-medial pressure on the head of the talus (Fig. 29-11). Serial manipulations and long leg cast applications are carried out just as with clubfoot management. Once the anterior tibialis and long toe extensors have stretched and the talonavicular joint is aligned, the child goes to the operating room for talonavicular joint pinning and Achilles tenotomy (Fig. 29-12).






Figure 29-12 After ensuring the talonavicular joint is reduced and pinned, the Achilles tendon is lengthened. (From Dobbs MB, Purcell DB, Nunley R, Morcuende JA. Early results of a new method of treatment for idiopathic congenital vertical talus: surgical technique. J Bone Joint Surg Am. 2007;89(suppl 2, Pt 1):111-121.)







Figure 29-13 A: In normal weight-bearing position, this patient has a very flat foot. B: When standing on his toes, the arch is visible. This dynamic change with foot position defines a flexible flatfoot.

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Jan 30, 2021 | Posted by in ORTHOPEDIC | Comments Off on Foot Problems
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