THE FOOT IN CEREBRAL PALSY- Part

1A TOPIC PRESENTATION

BY DR. LIBIN THOMAS MANATHARA

AMALA INSTITUTE OF MEDICAL SCIENCES

Topics• Introduction• Equinus Deformity• Surgical Correction of Equinus Deformity• WHITE MODIFICATION• Z-Plasty Lengthening of the Achilles Tendon• MOREAU AND LAKE

• Lengthening of the Gastrocnemius-Soleus Muscle• STRAYER

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Introduction

Introduction• Foot deformities caused by altered or abnormal muscle forces are

common in patients with cerebral palsy, with 70% to 90% of children affected. • The most common deformity is ankle equinus, with equinovarus and

equinovalgus deformities being equally common.

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Introduction• A foot deformity can have significant effects on the patient’s overall

ambulatory level. • The presence of a bilateral as opposed to a unilateral foot deformity,

regardless of the type, has been shown to have a significant effect on overall level of ambulation.

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Introduction• A patient’s deformity may change over time, especially in young

children. • For example, in a very young child with a valgus foot deformity,

persistent tonic reflexes and abnormal muscle forces may over time cause a varus foot position to develop.

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Introduction• Spasticity of the smaller muscles of the foot can lead to other

deformities, such as hallux valgus, claw toes, and forefoot adduction. • These can occur in isolation but more often occur in association with

other deformities related to abnormal extrinsic foot musculature.

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Equinus Deformity

Equinus Deformity• Equinus deformity is the most common foot deformity in patients

with cerebral palsy, affecting 70% of children, of whom approximately 25% develop a deformity severe enough to require operative treatment. • Conservative treatment consisting of stretching, bracing, botulinum

toxin A (BTX-A), and, occasionally, casting remains the primary form of treatment or means of delaying operative intervention.

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Equinus Deformity• The deformity is caused by spasticity of the gastrocnemius-soleus

muscle, which often worsens during periods of rapid growth because of overgrowth of the tibia relative to the gastrocnemius-soleus. • Animal models have shown that muscles in mice with hereditary

spasticity grow at a slower rate than normal muscle.

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Equinus Deformity• Ultrasound evaluation of the musculotendinous junction showed that

patients with cerebral palsy have longer Achilles tendons and shorter muscle bellies than normal controls. • Whereas ankle dorsiflexion increases in operatively treated patients,

the muscle-tendon architecture remains abnormal.

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Equinus Deformity• Bracing, especially at night, to prevent the foot from going into the

equinus position is essential. • The exact indications for surgery are unclear given the variable nature

of cerebral palsy; however, surgery typically is indicated when the ankle cannot be brought into the neutral position in an ambulatory child and when it leads to difficulties with hygiene, foot wear, and standing programs in a nonambulatory child.

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Surgical Correction of Equinus Deformity

Surgical Correction of Equinus Deformity• Because of the variable nature of cerebral palsy and the fact that

numerous procedures and postoperative regimens have been used in the treatment of equinus contracture, it is difficult to compare studies and success rates. • In addition, many recurrences are more than 5 years after the initial

operation and may not be included in short-term studies.

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Surgical Correction of Equinus Deformity• The recurrence rate in the literature ranges from 0% to 50%,

depending on the type of patient and the length of follow-up. • Younger patients, especially those younger than 3 years, and

hemiplegics are most likely to have recurrence. • Recurrence in patients older than 6 years is very rare.

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Surgical Correction of Equinus Deformity• The gastrocnemius-soleus can be lengthened at either the

musculotendinous junction with an aponeurotic recession or at the level of the Achilles tendon through an open or percutaneous approach. • For mild to moderate contractures, it is recommended that

lengthening be done at the level of the musculotendinous junction; the higher rate of overlengthening seen with the use of open Z-plasty techniques leads to residual weakness.

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Surgical Correction of Equinus Deformity• The use of the percutaneous approach has been shown in a small (28

feet) randomized, blinded study to provide rapid healing as demonstrated on ultrasound evaluation of the tendon, shorter operative and hospitalization times, postoperative dorsiflexion, and higher parental satisfaction. • Larger studies are necessary to further evaluate this.

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Surgical Correction of Equinus Deformity• Overlengthening of the gastrocnemius-soleus should be avoided,

especially in an ambulatory child, because it can cause weakness in push-off and crouch gait. • Because overlengthening is much less common with an aponeurosis

recession,this is preferred in ambulatory children and open Achilles lengthening may be reserved for patients with severe deformities that cannot be corrected by recession and for nonambulatory patients.

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Surgical Correction of Equinus Deformity• It is important to evaluate patients after release for toe flexion

contractures that have been unmasked after Achilles tendon lengthening, because this can lead to abnormal weight bearing on the tips of the toes. • This can be treated with simultaneous Z-lengthenings of the flexor

digitorum longus and flexor hallucis longus.

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Open Lengthening of the Achilles Tendon

Open Lengthening of the Achilles Tendon (WHITE MODIFICATION)• Use a posteromedial incision to expose the Achilles tendon from its

insertion to approximately 10 cm proximally, preserving the sheath.• Divide the posteromedial two thirds of the tendon near its insertion.• Apply a moderate dorsiflexion force to the foot, and divide the medial

two thirds of the tendon 5 to 8 cm proximal to the site of the distal division.

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Sliding lengthening of Achilles tendon. A, Posteromedial incision. B, Two cuts are made through one half of tendon in opposite directions. Rotation of fibers must be followed accurately. As foot is placed in dorsiflexion, tendon fibers separate.

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Open Lengthening of the Achilles Tendon (WHITE MODIFICATION)• Dorsiflex the foot so that the tendon lengthens to the desired length.• The tendon can be sutured in a side-to-side fashion with absorbable

suture.• Carefully close the tendon sheath and subcutaneous tissues to

prevent adherence of the tendon to the overlying skin.• Apply a short-leg cast with the ankle in maximal dorsiflexion.

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Postoperative Care• The patient is allowed to bear full weight on the leg postoperatively.• The cast is left on for approximately 4 weeks. • During this time, knee extension is encouraged to maintain the

lengthening of the gastrocnemius-soleus complex. • The cast is removed, and an ankle-foot orthosis is fitted with the

ankle in maximal dorsiflexion.

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Postoperative Care• Alternatively, a mold for a custom ankle-foot orthosis can be made at

the time of the initial procedure so that it is ready at the time of cast removal. • This is especially helpful if patient compliance and follow-up are

questionable. • The patient begins with full-time brace wear, and this is modified

depending on the patient’s growth remaining and progress in physical therapy.

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Z-Plasty Lengthening of the Achilles Tendon

Z-Plasty Lengthening of the Achilles Tendon• Make a posteromedial incision midway between the Achilles tendon

and the posterior aspect of the medial malleolus. • The lower extent of the incision is at the superior border of the

calcaneus, and it continues cephalad for 4 to 5 cm.

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Z-Plasty Lengthening of the Achilles Tendon• Expose the Achilles tendon with sharp dissection directed posteriorly

toward it.• Incise the sheath of the Achilles tendon longitudinally from the

superior to the inferior extent of the incision. • Free the tendon from the surrounding tissues.

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Z-plasty lengthening of Achilles tendon. A, Longitudinal incision, halfway between posterior aspect of medial malleolus and tendon. Longitudinal cut in tendon is brought out proximally in one direction and distally in opposite direction. B, Ends are sutured to repair tendon.

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Z-Plasty Lengthening of the Achilles Tendon• Make a longitudinal incision in the center of the Achilles tendon from

proximal to distal.• Turn the scalpel either medially or laterally distally, and divide that

half of the tendon transversely.

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Z-Plasty Lengthening of the Achilles Tendon• Make the distal cut toward the medial side for a varus deformity and

toward the lateral for a valgus deformity.• Hold this cut portion of the tendon with forceps, and bring the scalpel

to the proximal portion of the longitudinal incision in the tendon.

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Z-Plasty Lengthening of the Achilles Tendon• Turn the scalpel opposite the distal cut, and divide that half of the

tendon transversely to free the Achilles tendon completely.• Divide the plantaris tendon on the medial aspect of the Achilles

tendon transversely.• Evaluate the passive excursion of the triceps surae muscle using a

Kocher clamp to pull the proximal stump of the tendon to its maximally stretched length.

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Z-Plasty Lengthening of the Achilles Tendon• Allow the tendon to retract halfway back to its resting length, and

suture it to the distal tendon end at that point.• Control tension further by adjusting the foot position: neutral for mild

spasticity, 10 degrees of dorsiflexion for moderate involvement, and 20 degrees of dorsiflexion for severe deformity.

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Z-Plasty Lengthening of the Achilles Tendon• Perform the repair in a side-to-side manner with heavy absorbable

sutures.• Close the wound with absorbable sutures or subcuticular sutures and

skin strips, and apply a long-leg cast.

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Postoperative Care• Ambulation is allowed as soon as the patient is comfortable. When

pain is gone (usually 5 to 10 days), the cast is changed to a short-leg cast, and walking is continued. • Cast immobilization is continued for a total of 6 weeks. • Bracing is used if the anterior tibial muscle is not strong or is not

under volitional control.

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Postoperative Care• If there is no function in the anterior tibial muscle, full-time bracing is

required. • If the anterior tibial muscle functions only with withdrawal, full-time

bracing is required for several months and then at night only to prevent recurrence of the Achilles tendon contracture.

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Percutaneous Lengthening of the

Achilles Tendon

Percutaneous Lengthening of the Achilles Tendon• Moreau and Lake found that when done as an outpatient procedure,

percutaneous lengthening of the Achilles tendon was quick, inexpensive, and free of complications. • Of the 90 legs treated in this fashion, 97% showed improvement in

gait function.

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Percutaneous Lengthening of the Achilles Tendon (MOREAU AND LAKE)• With the patient prone and the leg prepared to the midthigh to

include the toes, extend the knee and dorsiflex the ankle to tense the Achilles tendon so that it is subcutaneous, easily outlined, and away from the neurovascular structures anteriorly.• Make three partial tenotomies in the Achilles tendon. • Make the first medial cut, just at the insertion of the tendon onto the

calcaneus, through one half of the width of the tendon.

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Incisions for percutaneous Achilles tendon lengthening. Cut ends slide on themselves with forceful dorsiflexion of foot.

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Percutaneous Lengthening of the Achilles Tendon (MOREAU AND LAKE)• Make the second tenotomy proximally and medially, just below the

musculotendinous junction. • Make the third laterally through half the width of the tendon midway

between the two medial cuts.

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Percutaneous Lengthening of the Achilles Tendon (MOREAU AND LAKE)• Place the two incisions on the medial side if the heel is in varus as it

usually is and on the lateral side if the heel is in valgus.• Dorsiflex the ankle to the desired angle.• The incisions do not require closure, only a sterile dressing and a

long-leg cast with the knee in full extension.

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Lengthening of the Gastrocnemius-Soleus

Muscle

Lengthening of the Gastrocnemius-Soleus Muscle• Strayer, in 1950, described an operation in which the aponeurotic

tendon of the gastrocnemius is divided transversely near its junction with that of the soleus, the ankle is dorsiflexed into the neutral position, and the retracted proximal part of the tendon is sutured to the underlying soleus. • Strayer believed the operation was helpful because it altered the

proprioceptive impulses received from the extremity, inhibiting abnormal stretch reflexes.

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Lengthening of the Gastrocnemius-Soleus Muscle• Many modifications of this procedure have been described, including

that by Vulpius, in which the aponeurotic tendon of the gastrocnemius is divided and the distal part is allowed to retract distally but is not sutured to the soleus.

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Lengthening of the Gastrocnemius-Soleus Muscle• Using radiographic markers, Craig and van Vuren showed that a

Strayer-type gastrocnemius-soleus recession provided the greatest degree of equinus correction because the origin of the soleus extends distally to the midportion of the tibia and fibula, which tethers the gastrocnemius tendon and decreases lengthening. • They also stated that reduction of spasm in the gastrocnemius is

essential when the equinus deformity is caused by a persistence of the positive support reflex or by a hyperactive stretch reflex.

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Lengthening of the Gastrocnemius-Soleus Muscle• For equinus deformity in which the chief cause of contracture is

spasticity or increased electrical activity in the gastrocnemius alone, one of the techniques described here is recommended. • Partial neurectomy in this situation is no longer indicated. • The procedure chosen should be based on the surgeon’s experience

and the unique clinical presentation of the patient.

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Gastrocnemius-Soleus Lengthening (STRAYER)

Gastrocnemius-Soleus Lengthening (STRAYER)• Make a posterior longitudinal incision over the middle of the calf at

the level of the musculotendinous junction, expose the aponeurosis of the gastrocnemius, and make an inverted or transverse incision through it. • Release this in a lateral-to-medial fashion to ensure complete release.• Release the raphes of the gastrocnemius-soleus and the plantaris

tendon completely.

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Gastrocnemius lengthening. A, Incision over posterior aspect of calf. B, Transverse cut through tendon. C, Foot is placed in dorsiflexion to neutral to separate tendon ends.

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Gastrocnemius-Soleus Lengthening (STRAYER)• Bring the ankle into slight dorsiflexion, which separates the ends of

the tendon.• If the aponeurosis of the soleus tendon is contracted, and further

correction is desired, divide it, but do not disturb the soleus muscle itself.

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Gastrocnemius-Soleus Lengthening (STRAYER)• Postoperative Care• Patients are placed in a short-leg cast for 4 weeks and allowed to bear

weight as tolerated. • Knee extension is encouraged, and physical therapy to maintain ankle

dorsiflexion is started after cast removal. • Patients are placed in a maximal dorsiflexion ankle-foot orthosis for

nighttime use for 6 months postoperatively.

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THANK YOU