Blaise Nemeth and Kenneth Noonan
DEFINITION
Clubfoot, also known as congenital talipes equinovarus, occurs in approximately 1 in 1000 live births.
The clubfoot contains four identifiable components that are easily remembered using the acronym CAVE (cavus, adductus, varus, and equinus). Idiopathic clubfoot contains each of the four components to varying degrees.
The so-called postural clubfoot is held by the infant in an equinovarus position, but all components are nearly completely correctable with gentle manipulation and resolve over time without intervention.
A small proportion of clubfeet are teratologic, occurring as part of other neuromuscular diseases, such as Larsen syndrome, any of the arthrogryposis syndromes, and spina bifida.
A severe type of idiopathic clubfoot, the complex clubfoot, has tighter hindfoot and plantar structures.
In 1948 Dr. Ignacio Ponseti began manipulating clubfeet through serial casting, completely correcting the clubfoot deformity. The principles of Ponseti casting lay in gradually stretching the soft tissue structures and gently inducing remolding of the primarily cartilaginous bones of the hindfoot during immobilization.
For the definitive publication on clubfoot and the Ponseti technique, the reader is referred to Dr. Ponseti's book.6
The success of the treatment protocol that bears his name has been borne out through over 30 years of follow-up, establishing it as the standard for initial treatment of clubfoot.1
Dr. Ponseti has recently published a modification to his original casting technique that addresses the specific deformities characteristic of the complex clubfoot.7
ANATOMY
The Achilles and posterior tibialis tendons, as well as the posterior and medial ligaments between the calcaneus, talus, and navicular, are thickened and fibrotic.6
The clubfoot contains a number of changes in bony alignment and shape (FIG 1).
Relative to normal foot anatomy, the first ray is plantarflexed, generating the cavus deformity. By comparison, all rays are plantarflexed in the complex clubfoot, resulting in full-foot cavus.
The navicular is medially displaced on the talus, and the cuboid is medially displaced on the calcaneus as part of the adductus deformity. The medial corners of the head of the talus and the anterior calcaneus are flattened.
The calcaneus is inverted under the talus, creating the hindfoot varus, while also being in equinus and elevated in the fat-pad of the heel.
In children with unilateral clubfoot, the affected foot is smaller, as is the lower leg, relative to the unaffected side.
Up to 85% of clubfeet have an insufficient or absent anterior tibial artery.5
NATURAL HISTORY
The exact cause of the fibrotic changes in clubfoot is unknown.
Left uncorrected, the weight-bearing surface in a clubfoot becomes the dorsolateral surface.
Thick callosities develop, and the positioning of the foot creates significant functional disability.
PATIENT HISTORY AND PHYSICAL FINDINGS
Clubfoot may be identified on prenatal ultrasound as early as 12 to 13 weeks (FIG 2).
Half or more of clubfeet identified on second-trimester ultrasounds have an association with other anomalies or are syndromic.8
The exact sensitivity and specificity of prenatal ultrasound are unknown, but there does appear to be variation with gestational age: the false-negative rate is thought to approach 0% but the false-positive rate may be as high 40% during the third trimester.8 Cases not found on prenatal ultrasound are readily identifiable at birth.
All children with clubfeet should be examined for other findings that may suggest a syndromic or neuromuscular association, such as other contractures or joint dislocations (especially hip dislocation), cutaneous lesions, spinal abnormalities, and abnormal facial features.
The clubfoot is easily identified by the combined deformities of cavus, adductus, varus, and equinus.
Consider complex clubfoot if a deep midfoot crease and cavus extend across the entire plantar aspect of the foot.
A deep heel crease, a nonpalpable calcaneus, and tight varus and equinus may suggest complex clubfoot.
The ability to abduct or dorsiflex the foot completely suggests etiologies other than idiopathic clubfoot, such as isolated metatarsus adductus, neuromuscular disease, or focal anatomic abnormalities.
The fat pad of the heel will feel empty upon palpation due to equinus positioning of the calcaneus. This is especially dramatic in the complex clubfoot.
The lateral head of the talus is easily palpable over the dorsolateral surface of the foot. More laterally, the anterior calcaneal tuberosity is also palpable. Care must be taken in differentiating these two structures because Ponseti casting necessitates free motion of the calcaneus under a talus that is stabilized over its lateral head, whereas pressure at the calcaneal tuberosity blocks calcaneal rotation, allowing only forefoot abduction.
The complex clubfoot has a crease that extends completely, or nearly so, across the plantar aspect of the foot. Full foot cavus is present, with plantarflexion of all metatarsals. Also, the heel crease is deeper than that of most other clubfeet. The first ray in the complex clubfoot, if not noticeably retracted at presentation, will become retracted during the initial one or two correctional casts, as the adductus is corrected, and the cavus will persist. All metatarsals remain plantarflexed.
FIG 1 • Anatomic alignment in neonatal clubfoot. Note the medial displacement of the navicular and cuboid, the inversion and internal rotation of the calcaneus under the talus, and equinus of the talus and calcaneus.
It is important to examine the clubfoot before each casting to evaluate for the adjustments that must be made during casting to correct residual deformities or to identify, and modify casting for, a complex clubfoot.
A number of classification systems have been introduced, the most commonly used being those of DiMeglio and Pirani. Both have utility in evaluating correction and recurrence, but the predictability of recurrence and final function is still unclear.4
The degree of dorsiflexion and abduction, and the distance of the navicular anterior to the medial malleolus, provide other objective measurements.
FIG 2 • Ultrasound at 20 weeks of a child born with clubfoot.
Some children are born with one or both feet held in an equinovarus deformity at birth that is nearly completely correctable on examination. Nearly complete dorsiflexion (more than 20 degrees) is present, although abduction may be slightly limited. The calcaneus is also readily palpable in the fat pad of the heel. These feet may be thought of as “postural” in nature, and most will resolve spontaneously or with parental stretching over 1 to 2 months.
If persistent, one or two casts usually correct the deformity, and no tenotomy is usually necessary because sufficient dorsiflexion is obtained with casting. Feet corrected with casting should be maintained in a foot-abduction orthosis.
IMAGING AND OTHER DIAGNOSTIC STUDIES
Plain radiographs at birth are not helpful in diagnosing clubfoot because the ossific nuclei of the talus and calcaneus are spherical, so orientation and relationship are not discernible, and the other tarsal bones are unossified.
Clinical examination is sufficient to diagnose the congenital clubfoot.
Once full abduction is obtained by casting, if dorsiflexion of more than 10 degrees is present, forced-dorsiflexion lateral films are helpful in differentiating midfoot breach, producing apparent dorsiflexion, from true dorsiflexion occurring at the ankle, suggesting the need for a percutaneous Achilles tenotomy (FIG 3).
DIFFERENTIAL DIAGNOSIS
Metatarsus adductus
Neurologic equinovarus or cavovarus deformity
Both deformities may be differentiated from clubfoot by absence of the other components of clubfoot.
Teratologic or syndromic clubfeet (including neuromuscular disorders)
Clubfoot deformity may be more difficult to correct or may tend to recur.
“Postural” clubfoot
Complex clubfoot
NONOPERATIVE MANAGEMENT
Ponseti casting of the idiopathic clubfoot involves a specific sequence of corrective maneuvers that correct the deformities of the clubfoot in combination.
Each manipulation is maintained with a plaster cast.
Resolution of the deformities occurs simultaneously, but complete resolution sequentially follows the acronym CAVE.
Ponseti casting can be performed successfully in children up to 2 years old, although any correction obtained by casting in older children may reduce the amount of surgery required for complete correction.
An open tendo-Achilles lengthening may be more appropriate than a percutaneous tenotomy in children over 2 years old.
Long-leg casts should always be used.
A short-leg cast should be applied first so that attention is made solely to molding around the ankle before extending the cast above the knee.
Padding should be minimal, and plaster is preferable for its ability to be molded precisely to the contours of the foot and ankle.
Four to six casts should correct the cavus, adductus, and varus deformities. If correction is not achieved in eight casts or the child pulls back in the casts (FIG 4A), the possibility of an unrecognized complex clubfoot or improper casting technique should be considered.
FIG 3 • A. Dorsiflexion of right clubfoot after five corrective casts, before tenotomy. Dorsiflexion of 10 degrees would appear to be sufficient to avoid Achilles tenotomy. B. Forced dorsiflexion lateral radiograph of same foot. Dorsiflexion of the metatarsals relative to the axis of the talus reveals the source of clinical dorsiflexion. The calcaneus is still in equinus (relative to the tibial axis) and a percutaneous Achilles tenotomy is required to complete the correction. C. Forced dorsiflexion lateral radiograph of the left (uninvolved) foot. The calcaneus is dorsiflexed and the axis of the first metatarsal is almost parallel to the axis. D. Forced-dorsiflexion lateral radiograph of the right foot 3 weeks after the percutaneous Achilles tenotomy. Now the calcaneus is dorsiflexed relative to the tibial axis and what was seen on the pretenotomy radiograph (B).
FIG 4 • A. A complex clubfoot that has pulled back in the cast. The cast was originally trimmed dorsally to the web spaces of the toes. The heel is elevated in the cast and the toes are no longer visible. B.Purple discoloration of toes after application of the first cast, as the cast begins to cool. C. One hour later, the cast temperature has stabilized and the toes are pink.
Casting is facilitated by the child being relaxed and calm. Feeding the infant during casting, playing music, or allowing the child to play with toys may assist in this.
For breast-fed infants, it is helpful if the family introduces, and uses once daily, a bottle so that one can be used during casting. If a bottle is not tolerated, having the child suck on a finger that has been dipped in sugar water may be successful.
Before leaving the clinic, the toes should be checked to make sure they are pink and well perfused.
Some toes will become reddish-purple as the casts cool (appearing much like the acrocyanosis present at birth) but will become more pink if the child is bundled and monitored over 1 hour or so (FIG 4 B,C).
Toes that become more purple and dusky indicate that the cast is too tight and should be reapplied.
Casts are changed every 5 to 7 days. The final cast, following percutaneous Achilles tenotomy, is left in place for 3 weeks.
Approximately 95% of clubfeet will require a percutaneous Achilles tenotomy to correct the residual equinus deformity once the other components are corrected.
Once complete correction is obtained, correction must be maintained by placing the feet in a foot-abduction orthosis (FIG 5A).
Some straight-last shoes will need modifications to keep the feet secured (FIG 5B,C), while others require a custom orthosis (FIG 5D) (see “Postoperative Management”).
SURGICAL MANAGEMENT
Percutaneous Achilles tenotomy is required in 95% of idiopathic clubfeet to correct the residual equinus.
About 20% of patients require anterior tibialis tendon transfer to correct recurrent or persistent dynamic varus deformity.
Preoperative Planning
Degree of dorsiflexion
If dorsiflexion is less than 10 degrees, a percutaneous Achilles tenotomy is required to correct the residual equinus.
If dorsiflexion is more than 10 degrees, forced-dorsiflexion lateral foot radiographs help to differentiate midfoot dorsiflexion, with residual calcaneal equinus, from true dorsiflexion occurring at the hindfoot (see Fig 3).
Location
The risk of anesthesia must be balanced against the perceived pain and duration of the procedure, as well as the degree of sedation necessary for safe performance of the procedure and optimizing posttenotomy casting.
Many institutions prefer local anesthesia with 1% lidocaine, with the procedure performed in the clinic, for infants owing to the high risk of general anesthesia. Others use a eutectic mixture of lidocaine anesthetic cream left in place over the heel. Some institutions require general anesthesia in the operating room, and some providers prefer the guaranteed sedation and pain control afforded in this setting, especially for children over 6 months old.
Sedation in a pediatric sedation clinic may be another alternative.
Positioning
The child should be supine on the table with the contralateral leg held out of the way by the parent or an assistant during casting and tenotomy.
Approach
A medial approach is used to avoid the medial neurovascular bundle.
FIG 5 • The foot-abduction orthosis. A. Straight-last shoes are attached to the bar at shoulder width with the buckles along the medial aspect of the shoe to ease application. B. Both shoes should be placed in 60 degrees of abduction in cases of bilateral clubfoot. C. Plastizote padding added to the heel counter of the straight-last shoe prevents plantarflexion and helps keep the foot in the shoe. This shoe also has a heel cut-out to confirm that the heel is well seated in the shoe. The lower edge of the Plastizote should sit in the recess above the posterior calcaneal tuberosity to help prevent lifting of the heel and plantarflexion of the foot. D. A custom-molded foot-abduction orthosis used in a case of complex clubfoot.
TECHNIQUES
CASTING
Stretching
Before casting, the foot should be stretched in the same manner as used for immobilization during casting (TECH FIG 1A,B).
The thumb of the examiner's contralateral hand (eg, the left hand when manipulating the right foot) should be placed over the head of the talus, and the index finger of the other hand should lie along the medial aspect of the first ray with the second through fourth fingers under the plantar aspects of the forefoot.
The calcaneocuboid joint should be avoided, so as not to block subtalar motion.
The first casting should focus on elevation of the first ray to correct the cavus deformity (TECH FIG 1C).
This places the forefoot in supination, locking the midfoot and aligning the forefoot with the hindfoot, providing a lever arm for correction of the hindfoot deformities during later abduction maneuvers.
Some of the adductus may also be corrected during the first casting.
Lower-Leg Cast Application
A thin layer of cotton padding should be applied.
The padding is wrapped three times around the toes distally, then extended proximally over the foot and lower leg to pad with no more than two layers of padding.
The foot should be held in the position to be casted throughout (TECH FIG 2A). The popliteal fossa should be avoided proximally.
A thin layer of plaster is applied over the foot and lower leg.
The plaster may be applied more loosely over the toes but should be snug over the hindfoot and ankle to immobilize the foot properly and allow for precise molding (TECH FIG 2B).
TECH FIG 2 • A. The foot should be held in the position of correction. Casting of the lower leg begins with two layers of cotton padding. B. A thin amount of plaster is applied and the foot is held in position while the plaster sets. The thumb provides counterpressure over the lateral head of the talus as the foot is abducted; the fingers of the same hand mold above the calcaneus and around the malleoli. The fingers should remain in constant motion.
Avoid making the cast too snug so as to impair venous return or apply pressure on the fat pad of the heel.
The lower-leg cast should be precisely molded around the malleoli and above the calcaneus posteriorly using the index and middle finger of the same hand as the thumb that is immobilizing the talus.
Do not apply pressure over the fat pad of the heel.
Throughout, the foot should be held in the position of correction, but the fingers should be in fairly constant motion to prevent pressure spots within the minimally padded cast.
TECH FIG 1 • A. The thumb should be placed over the lateral head of the talus, just anterior to the lateral malleolus, during all corrective maneuvers, including during stretching and casting. B. The fingertips of the opposite hand are placed under the heads of the metatarsals of the foot to keep all rays aligned. The index finger is placed slightly more medially on the first ray to provide an abduction force to the forefoot. C. The first casting corrects the cavus deformity by elevation of the first ray, bringing it into alignment with the other rays.
Completing the Cast
Once the lower-leg cast has set, padding should be applied over the rest of the leg up to the groin, again in no more than two or three layers.
The knee should be held at 90 degrees, and the lower leg should be in slight external rotation.
Padding should be minimized in the popliteal fossa to prevent impingement of the neurovascular structures. The padding should be wrapped three to five times over the proximal thigh to pad adequately.
Plaster should then be wrapped over the short-leg cast above the ankle and extended proximally over the padded knee and thigh to the groin. A plaster splint of three or four layers of plaster roll should be placed over the knee from the middle of the thigh to the middle of the shin to strengthen the cast against knee extension while minimizing bulk in the popliteal fossa. The plaster is then wrapped distally to incorporate the splint, ending once the lower leg has been completely incorporated.
The knee should be molded while held at 90 degrees with the lower leg in slight external rotation until set (TECH FIG 3A). Rolling the plaster at the proximal edge of the cast before the plaster sets up completely helps minimize chafing of the thigh.
The cast should be trimmed distally to expose the toes. The surgeon should confirm that they are pink and well perfused (TECH FIG 3B) before the child is sent home.
TECH FIG 3 • A. Padding and plaster are applied up to the proximal thigh, incorporating the short-leg cast into a long-leg cast. The knee is flexed to 90 degrees. The proximal margin of the cast is rolled to decrease skin irritation. B. The distal end of the cast is trimmed to the web space of the toes dorsally, revealing pink, well-perfused digits. A plantar toe plate remains.
Trimming the plaster over the dorsal aspect too far proximally, beyond the web space, may create a tourniquet effect over the forefoot.
A plantar toe plate should be left to prevent toe flexion and curling, which may facilitate pulling out of the cast.
Parents should be instructed on signs and symptoms of cast problems before discharge.
Cast Changes and Follow-Up
Casts are ideally changed every 7 days, although they may be changed as frequently as every 5 days; up to 2 weeks may be tolerated if necessary to accommodate conflicts preventing weekly cast changes.
Casts should not be removed until just before recasting.
They can be soaked by the family before coming to the office, then removed with a plaster knife in the clinic.
Alternatively, dry casts may be removed with a cast saw, using extreme caution.
Having the parents remove the casts the night before results in varied degrees of recurrence overnight and prolongs casting.
After the first casting, the cavus deformity should be nearly, or completely, corrected.
Abduction may be increased.
Stretching is performed with the forefoot in supination, maintaining alignment of all rays, abducting the foot under the talus.
The foot is then casted in the newly maintained position, just to where the foot may be comfortably corrected without significant resistance.
Trying to overabduct the foot during a single casting results in intolerance as the foot tries to return to its position of comfort, and in the worst cases results in pressure sores or vascular compromise of the soft tissues along the medial foot. A keen sense of touch and patience are essential.
Each subsequent manipulation results in increased abduction of the forefoot and correction of the hindfoot varus (TECH FIG 4A–D).
Throughout, the forefoot should remain in neutral (appearing supinated due to the hindfoot varus) and the hindfoot in equinus (TECH FIG 4E).
Dorsiflexion of the calcaneus remains blocked under the neck of the talus until approximately 25 degrees of abduction has been obtained. Dorsiflexion before that point results in midfoot, and not subtalar, dorsiflexion (see Fig 3).
Subsequent eversion of the calcaneus will bring the forefoot and hindfoot into more neutral positions and dorsiflexion may be obtained by percutaneous Achilles tenotomy.
Once abduction of 70 degrees is obtained (TECH FIG 4F), correction of the remaining equinus deformity may occur.
Overabduction to 70 degrees is necessary to accommodate some of the inevitable recurrence, without allowing progression beyond a normal position that would require recorrection.
TECH FIG 4 • A. Adduction is decreased in the second cast. B. By the third cast, the foot is in line with the leg. C. By the fourth casting, the foot is abducted 20 degrees and held in this position with the cast. D. With the fifth cast, the foot is now held at 45 degrees of abduction. E. Before the tenotomy, the foot remains in plantarflexion throughout abduction. F. After removal of the fifth cast, the foot can be abducted 70 degrees and is ready for percutaneous Achilles tenotomy. The amount of dorsiflexion in this foot is seen in Figure 3.
COMPLEX CLUBFOOT
The complex clubfoot may not be immediately recognizable at presentation.
Correction usually begins using the standard maneuvers, elevating the first ray with the first cast and continuing abduction with the second cast.
Within one or two casts, the foot begins to clearly demonstrate a demarcation from the expected correction as the cavus persists and evolves, involving plantarflexion of all metatarsals, and the first ray becomes retracted.
At this point, the technique must be modified.
In the complex clubfoot, the tight plantar intrinsics and toe flexors induce full-foot cavus. This is exacerbated by the tight hindfoot structures, which also limit correction of the varus to just beyond neutral.
As a result, the casting technique must be modified not only to correct these features, but also to decrease the propensity for pulling out of even long-leg casts.
Lateral counterpressure still occurs at the lateral head and neck of the talus, but stabilization of the fibula should also occur.
The index finger of the contralateral hand (eg, the examiner's left hand when manipulating a patient's right clubfoot) should be flexed at 90 degrees at the proximal interphalangeal joint and placed posterior to the distal fibula.
The thumb of the same hand is placed just anterior to the lateral malleolus along the neck of the talus.
As the foot begins to approach neutral, the full-foot cavus, along with the dramatic equinus, can pose significant casting difficulties.
The foot becomes contiguous with the lower leg, absent any ankle dorsiflexion, and the cavus shortens the foot, making it even more difficult to immobilize.
A posterior splint of three or four layers of plaster should be applied under the plantar surface of the foot, extending from beyond the tips of the toes proximally over the posterior lower leg.
As in the upper-leg portion of the traditional cast, the posterior splint about the foot strengthens the plantar portion of the cast against the forceful plantarflexion of the complex clubfoot without increasing bulk over the anterior ankle, which may impede molding and immobilization.
Then, a thin layer of plaster may be wrapped in the usual manner to encompass the foot and lower leg. A minimal amount of plaster should be used because precise molding is even more important for the complex clubfoot.
The pads of the thumbs of both hands may be placed under the forefoot, with the pads of the index fingers placed over the dorsal surface of the talar neck, anterior to the medial and lateral malleoli, with the pads of the middle fingers posterior to the malleoli. The forefoot is then forcefully dorsiflexed against the counterpressure over the dorsal talar neck, enough to produce blanching of the digits (presumably due to tension constriction of the posterior tibial and peroneal arteries) (TECH FIG 5A).
Further counterpressure to dorsiflexion is applied over the anterior thigh above the flexed knee.
Upon release of dorsiflexion pressure after setting of the cast, the slight relaxation of the cast will result in revascularization of the digits (TECH FIG 5B).
Care should be taken not to abduct the foot beyond 45 degrees because the tight hindfoot prevents further progression of the hindfoot into valgus, and abduction of the forefoot only occurs.
On extending the cast up over the lower leg, the knee should be flexed to 110 degrees to minimize the ability to pull out of the cast. An anterior plaster splint over the thigh and knee should be used just as in the traditional technique.
Tenotomy occurs once the cavus and adductus deformities are corrected, and about 40 degrees of abduction is obtained.
Attempting to abduct the complex clubfoot beyond 40 degrees results in no further hindfoot correction and only overabducts the forefoot, making immobilization of the foot in the cast more difficult.
TECH FIG 5 • A. When casting the complex clubfoot, to correct the full-foot cavus, a dorsiflexion force is applied to dorsiflex at the midfoot. The fat pads of both thumbs are placed under the heads of the metatarsals, with the index fingers over the dorsal aspect of the talar neck, and the middle fingers placed behind the malleoli to help mold the cast. B. When dorsiflexing the complex clubfoot during initial castings (before tenotomy), the toes should blanch. When dorsiflexion pressure is released, the slight relaxation of the cast results in reperfusion of the digits. In this case, blood flow returned initially to the first, fourth, and fifth digits; the second and third became pink a few moments later.
PERCUTANEOUS ACHILLES TENOTOMY
The tenotomy should occur 1 to 1.5 cm above the insertion of the Achilles on the posterior tuberosity of the calcaneus.
In many feet, this is 1 to 1.5 cm above the posterior heel crease.
Performing the tenotomy too low results in damage to the posterior calcaneal tuberosity.
For procedures in the clinic, local anesthesia must be used.
A small amount of 1% lidocaine may be injected locally over the tendon at the site of blade insertion before the procedure, taking care not to inject so much as to obscure the ability to discern the Achilles tendon for the procedure (TECH FIG 6A). Usually less than 0.05 mL is sufficient.
Alternatively, a eutectic mixture of lidocaine anesthetic cream may be used topically. It should be left in place for at least 45 minutes for maximal effect. Blanching of the skin correlates with the anesthetic effect.
An assistant should hold the foot in maximal dorsiflexion to increase tension on the Achilles tendon, making it more easily palpable and able to be transected (TECH FIG 6B).
A second assistant should hold the contralateral leg and foot out of the field.
A thin, sharp scalpel should be used to perform the tenotomy. Cataract surgical blades (5100 or 5400 Beaver blades) are well suited for this procedure, although an 11 blade is also acceptable. One of two techniques may be used to insert the blade:
The blade of the scalpel may be inserted perpendicular to the skin, anterior to the Achilles tendon, from the medial side, with the blade itself oriented parallel to the longitudinal axis of the tendon. The blade must be advanced far enough to pass beyond the lateral side of the tendon so that complete transection occurs. Once advanced far enough, the blade may be rotated in place, orienting the blade perpendicular to the tendon (TECH FIG 6C).
Alternatively, the blade may be advanced anterior to the tendon at a 45-degree angle to the skin, again advancing the tip of the blade deep enough to pass the lateral side of the tendon, but with the blade oriented perpendicular to the tendon from the outset. The handle of the scalpel may then be lifted ventrally, bringing the blade perpendicular to the skin, resting against the tendon (TECH FIG 6D).
TECH FIG 6 • A. Local anesthesia for percutaneous Achilles tenotomy of the left foot. Lidocaine is injected 1 to 1.5 cm above the insertion of the Achilles tendon on the calcaneus, which in this case occurs at the level of the hindfoot crease. B. An assistant dorsiflexes the left foot, applying tension to the Achilles tendon, making it easier to palpate and transect with the scalpel. C. One of the two techniques used to insert the scalpel blade and transect the tendon. (The illustration is of the left foot.) The handle of the scalpel is perpendicular to the skin over the medial heel cord, with the blade parallel to the axis of the tendon. Once the tip of the blade has been advanced beyond the lateral edge of the tendon, the blade is turned perpendicular to the tendon (arrow). D. The second of the two techniques for blade insertion. (The illustration is of the left foot.) The handle and the blade are advanced at a 45-degree angle to the skin, with the sharp edge of the blade oriented perpendicular to the tendon. Once advanced deeply enough for the tip to be beyond the lateral edge of the tendon, the handle is swung anteriorly to bring the blade into contact with the tendon (arrow). The handle is now perpendicular to the skin. E. Transection of the Achilles tendon of the left foot. Pressure is applied with the contralateral thumb, pressing the tendon onto the blade, resulting in tendon transection. The level of the tenotomy is 1 cm above the posterior heel crease. F. The foot is in plantarflexion before the tenotomy. G. After the tenotomy, 30 degrees of dorsiflexion is obtained. In extreme dorsiflexion the digits blanch, presumably due to impingement of the posterior tibial artery. Decreasing dorsiflexion just a few degrees resulted in reperfusion. H. During application and molding of the short-leg cast, the foot should be held in maximum dorsiflexion and abduction. An assistant provides counterpressure above the knee. Dorsiflexion pressure is applied only over the plantar aspect of the midfoot and forefoot and the heel remains untouched, while the cast is molded around the ankle with the fingers of the other hand.
Once the blade is oriented perpendicular to the fibers of the Achilles tendon, the safest maneuver involves pressing the tendon onto the blade using the contralateral thumb (TECH FIG 6E).
Complete transection often results in a palpable “pop,” release of the Achilles tendon, and an immediate increase of 15 to 20 degrees of dorsiflexion (TECH FIG 6F). A palpable defect in the tendon confirms complete transection.
If incomplete transection occurs, the tendon should be revisited, adjusting blade position as necessary, to complete the release.
Care should be taken not to pull the blade through the tendon lest laceration of the overlying skin occur once the resistance of the tendon disappears following transection.
The Betadine should be cleansed from the skin to prevent Betadine burns to the neonatal skin, and pressure should be applied to the incision site to stop all bleeding before cast application.
The foot should now be held in the new position of maximum dorsiflexion and abduction.
In some cases, the increased dorsiflexion will increase traction on the solitary posterior tibial artery as it passes under the medial malleolus, constricting it and resulting in blanching of the digits (TECH FIG 6G).
The lower leg is wrapped with sterile cotton in the usual manner, accommodating the increased dorsiflexion.
The plaster is applied in the usual manner, and the cast must be molded well at the anterior ankle to accommodate the increased dorsiflexion and prevent pulling back in the cast (TECH FIG 6H).
For the complex clubfoot, the posterior plaster splint should be used in the short-leg cast.
On release of dorsiflexion pressure after setting of the cast, the slight relaxation of the cast will result in revascularization.
If revascularization does not occur, the cast may need to be removed and reapplied. Although maximum dorsiflexion is prevented because of vascular compromise, what is gained is usually sufficient for adequate correction without the need for a second tenotomy or later recorrection.
Casting
Extension of the cast above the thigh as a long-leg cast should occur with the knee in the usual 90 degrees of flexion, first with padding (TECH FIG 7A) and then with plaster, holding the lower leg in slight external rotation (TECH FIG 7B).
The complex clubfoot should have the knee flexed at 110 degrees.
An anterior knee splint should be used in both cases.
The posttenotomy cast should be left on for 3 weeks before removal to allow tendon healing.
Frequently, blood seeps through the cast and becomes visible, and parents should be alerted to this.
Persistent bleeding, resulting in a spot above the heel larger than a quarter in size, may signify injury to vascular structures on the lateral aspect of the foot, rarely requiring any intervention other than further assessment.2
When the cast is removed, complete correction should have been obtained (TECH FIG 7C,D).
TECH FIG 7 • A. Cotton padding is applied from the proximal edge of the short-leg cast up to the groin. B. With extension to the long-leg cast, the lower leg is held in slight external rotation, and the knee is held at 90 degrees of flexion. The foot is now in maximum dorsiflexion and abduction. C,D. Three weeks after tenotomy, after the final cast is removed, complete correction is obtained. C. The foot abducts 70 degrees. D. The foot actively dorsiflexes 20 degrees.
POSTOPERATIVE CARE
After removal of the posttenotomy cast, the child should immediately be placed in a foot-abduction orthosis. Most fully corrected idiopathic clubfeet will tolerate standard orthoses consisting of open-toed, straight-last shoes connected by a bar.
In the case of bilateral corrected clubfeet, both shoes should be placed in abduction and external rotation on the bar to the degree of comfortable correction, typically 55 to 60 degrees (see Fig 5D).
For unilateral clubfoot, only the shoe of the affected foot is placed near the extreme of abduction. The shoe of the uninvolved, normal foot is placed at 35 degrees of abduction and external rotation. The shoes should be placed at shoulder width on the bar.
Mounting the shoes on the bar such that the buckle of the anterior ankle strap is on the medial aspect of the foot eases application of the orthosis (see Fig 5D).
In cases of unilateral clubfoot, application of the orthosis is easier if the affected foot is placed into its shoe first, followed by the normal foot. In bilateral cases, one foot is usually “tighter” (more resistant to correction or had less correction from the tenotomy), and this is the one that should be placed in the orthosis first.
The anterior ankle strap secures the foot in the shoe and should be tightened sufficiently to prevent pulling the foot out of the shoe. The laces should be pulled only tight enough to conform the shoe to the foot. Tightening further may cause venous congestion and extreme discomfort.
If the foot is not secured in the shoe, Plastizote pads should be used. Usually a pad placed in the heel of the shoe, positioned so that the inferior edge rests just above the posterior tuberosity of the calcaneus, is sufficient.
If necessary, pads on the tongue and/or under the toes may provide further limitations to pulling the foot out of the shoe.
In some cases, the tongue provides an obstruction to securing the foot, and removing the tongue may actually improve the ability of the strap to secure the foot.
Other modifications that may help prevent pulling out include lacing the shoes from the ankle down to the toe, slightly decreasing the degree of external rotation of the shoes (no less than 45 degrees), or widening the bar slightly beyond shoulder width.
Only a single, thin pair of socks should be worn with the shoes. For the first 1 or 2 days, two socks may be used to prevent blisters (much like the double-sock method used by runners), but thereafter only one pair should be used.
Thick, well-padded socks prevent adequate securing of the foot and make it easier to pull the foot out of the shoe.
For the first week, the orthosis and socks should be removed with every diaper change to inspect the feet for evidence of developing pressure sores.
Red spots that do not disappear within 5 minutes signal a potential problem spot and require refitting of the shoes with Plastizote or repositioning on the bar.
Care should be taken to remove the orthosis when the child is calm to prevent the child from associating crying with subsequent removal, resulting in persistent resistance to orthosis wear with unrelenting crying.
After casting, the leg and foot are hyperesthetic.
Massaging the leg, initially deeply and progressing to light touch, with each diaper change during the first week helps with desensitization.
The lower leg may also develop intermittent purple discoloration when dependent to gravity after casting. This usually resolves over the first month out of casts.
After the first week, the orthosis should be worn full time, but it may be removed once daily for bathing and a short period of play (1 to 2 hours).
Full-time wear continues for 3 to 4 months to maintain correction.
Tighter feet, or those more difficult to correct, may benefit from periodic stretching in dorsiflexion and abduction whenever the orthosis is removed.
Children should be re-examined in and out of the orthosis after 1 month, then 2 months later.
After 3 months of full-time wear and maintenance of full correction, children wear the orthosis only during periods of sleep, at nighttime, and during naps.
Children should be examined every 3 to 6 months, depending on the level of concern regarding recurrence, until bar and shoe wear is complete.
Any episodes of recurrence warrant recasting as soon as identified.
Casting is performed in the usual manner to obtain complete correction again.
Casting is usually sufficient to correct the recurrence. Rarely, a repeat percutaneous tenotomy is necessary for more severe recurrence. Once complete correction is again obtained, orthosis wear occurs for 3 months full time before resuming part-time wear.
Straight-last shoes may be worn until the child's toes curl over the edge of the shoe. Then the next appropriate size should be fitted and attached to the bar.
Part-time wear continues until the child is 4 years old, when orthosis wear may be discontinued. Children should be monitored for recurrence, which occurs rarely after 4 years old.
Complex clubfeet almost always pull out of standard straight-last shoes. A variety of newer bar-and-shoe constructs have been developed to address the limitations of current standard orthoses, including one developed by Dr. Ponseti (see Fig 5D).
OUTCOMES
A corrected clubfoot tends to recur to its original position, requiring maintenance of correction in the orthosis. Noncompliance with bar-and-shoe wear increases the likelihood of recurrence to more than 80%. Compliance is increased with close follow-up and explicit discussions with the family and all caregivers.3
Twenty percent to 50% of corrected clubfeet will require anterior tibialis tendon transfer to correct dynamic varus present during ambulation (see Chap. PE-92).
COMPLICATIONS
Cast sores, cast saw burns
Prolonged casting or pulling back in the cast due to improper technique, unrecognized clubfoot, or failure to modify casting for complex clubfoot
Overabduction from unrecognized complex clubfoot or overabduction in foot abduction orthosis (beyond degree of correction)
Posterior tibial artery impingement
Peroneal artery or lesser saphenous vein laceration during tenotomy2
Pulling back in cast from poor cast molding, unrecognized complex clubfoot, or not enough knee flexion in long-leg cast if complex clubfoot
Recurrence due to incomplete correction or lack of orthosis wear
REFERENCES
· Cooper DM, Dietz FR. Treatment of idiopathic clubfoot: a thirty-year follow-up note. J Bone Joint Surg Am 1995;77A:1477–1489.
· Dobbs MB, Gordon JE, Walton T, et al. Bleeding complications following percutaneous tendo Achilles tenotomy in the treatment of clubfoot deformity. J Pediatr Orthop 2004;24:353–357.
· Dobbs MB, Rudzki JR, Purcell DB, et al. Factors predictive of outcome after use of the Ponseti method for the treatment of idiopathic clubfeet. J Bone Joint Surg Am 2004;86A:22–27.
· Flynn JM, Donohoe M, Mackenzie WG. An independent assessment of two clubfoot-classification systems. J Pediatr Orthop 1998;18: 323–327.
· Greider TD, Siff SJ, Gersen P, et al. Arteriography in club foot. J Bone Joint Surg Am 1982;64A:837–840.
· Ponseti IV. Congenital Clubfoot: Fundamentals of Treatment. New York: Oxford University Press, 1996.
· Ponseti IV, Zhivkov M, Davis N, et al. Treatment of the complex idiopathic clubfoot. Clin Orthop Relat Res 2006;451:171–176.
· Treadwell MC, Stanitski CL, King M. Prenatal sonographic diagnosis of clubfoot: implications for patient counseling. J Pediatr Orthop 1999;19:8–10.