THE FOOT IN CEREBRAL PALSY- Part

2Topic Presentation

Amala Institute of Medical Sciences, ThrissurDepartment of OrthopaedicsDr. Libin Thomas Manathara

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TOPICS• PART 1- Equinus deformity• PART 2- Valgus or varus deformity• Equinovarus deformity• Split tendon transfers• Osteotomy of the calcaneus • PART 3- Valgus or varus deformity, continued…• Equinovalgus deformity• Calcaneus deformity• Cavus deformity • Forefoot adduction deformity• Hallux valgus deformity• Claw toes

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Varus or Valgus Deformity

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Varus or Valgus Deformity- Introduction• Varus and valgus deformities can occur in patients with cerebral

palsy, most commonly in association with an equinus deformity• It has been shown that TA (tibialis anterior or anterior tibial muscle)

muscle dysfunction alone or in combination with dysfunction of the TP (tibialis posterior or posterior tibial muscle) muscle is more commonly the cause of Varus deformity than isolated TP dysfunction

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Varus or Valgus Deformity• In hemiplegia the foot deformity has been found to be either equinus

or equinovarus• In diplegia and quadriplegia it was valgus or varus• Although less common, varus deformities are • more functionally disabling • more difficult to manage nonoperatively and • easier to correct operatively

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Varus or Valgus Deformity• Consequently, surgery is done more often and more successfully for

varus than for valgus deformities

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Varus or Valgus Deformity• The biomechanics of the hip and knee also influence whether a varus

or valgus deformity is present • Diplegic patients typically have • internally rotated and adducted hips • flexed knees• external rotation deformity of the tibia

• This combination of deformities causes the foot to assume a valgus position

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Varus or Valgus Deformity• In hemiplegic patients, the internally rotated thigh with the knee

coming to full extension in stance phase causes the foot to internally rotate and produce a varus deformity

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Equinovarus Deformity

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Equinovarus Deformity• The normal posterior tibial muscle is active during stance phase to

stabilize the foot and inactive during swing phase• In cerebral palsy, the TP contracts during swing phase, leading to the

varus position of the foot at heel strike

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Equinovarus Deformity• It is essential to determine which muscles are responsible for the

deformity before any attempt at surgical correction • It also is important to determine whether the deformity is flexible and

correctable or rigid

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Equinovarus Deformity• Patients with flexible deformities are more likely to be successfully

treated nonoperatively with orthotics and shoe modifications and operatively with soft tissue procedures such as tendon lengthenings, releases, or transfers (usually of the abnormally active muscle)• Patients with rigid varus deformities generally require bone

procedures, such as calcaneal osteotomy

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Lengthening of the Posterior Tibial Tendon

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Lengthening of the Posterior Tibial Tendon• The posterior tibial tendon can be lengthened in a variety of ways,

including open Z-plasty of the tendon itself and various recession procedures, such as step-cut lengthening and intramuscular lengthening• A Z-plasty lengthening of the tendon, although it gives a large amount

of correction, can cause scarring and tethering of the tendon in its sheath, leading to recurrence of deformity

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Lengthening of the Posterior Tibial Tendon• Recession procedures such as lengthening at the musculotendinous

junction have a lower risk of overlengthening and scarring of the tendon sheath• Recession procedures, because the tendon itself is spared, are good

for patients at high risk of recurrence or in whom a posterior tibial transfer may be needed in the future

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Musculotendinous Recession of the Posterior Tibial Tendon

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Musculotendinous Recession of the Posterior Tibial Tendon• Place the patient supine, and make a 3-cm longitudinal incision over

the posteromedial aspect of the tibia, at the junction between the middle and distal thirds• Incise the deep fascia, and identify the flexor digitorum longus and

retract it posteriorly• Identify the posterior tibial musculotendinous junction by placing a

hemostat beneath it and observing its action when inverting the foot without flexing the toes

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Musculotendinous Recession of the Posterior Tibial Tendon• Pass a hemostat around the tendinous portion of the

musculotendinous junction to isolate it from the surrounding muscle, protecting the neurovascular bundle• Divide the tendinous portion of the posterior tibial musculotendinous

unit, leaving its muscular fibers intact • Manipulate the foot into an overcorrected position • Close the wound, and apply a short-leg walking cast

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Split Tendon Transfers

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Split Tendon Transfers• Depending on the muscles that are out of phase, split tendon

transfers of the posterior or anterior tendon can be done • Full tendon transfers should be avoided because of the higher risk of

complications and overcorrection of the deformity

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Split Tendon Transfers• Preoperatively, it is essential to ensure that the deformity is flexible

and to identify the correct tendon to be transferred• The split transfer not only improves active muscle function during gait

but also acts as a dynamic sling, balancing the abnormal forces evenly across the foot

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KLING, KAUFER, HENSINGER- Posterior tendon transfer• Begin the first of two incisions 5 cm proximal and medial to the

medial malleolus, and extend the incision distally, ending over the navicular• Identify the posterior tibial muscle and tendon• Identify and protect the neurovascular bundle

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KLING, KAUFER, HENSINGER• Open the anterior aspect of the tendon sheath preserving the

posterior tunnel to prevent dislocation of the tendon• Dissect the plantar portion of the posterior tibial tendon from its

insertion on the navicular, preserving as much length for transfer as possible• Deliver this portion of the tendon into the proximal aspect of the

wound, and place a nonabsorbable suture in the free end of the tendon

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KLING, KAUFER, HENSINGER• Make a second incision over the lateral side of the ankle 2 cm

proximal to the lateral malleolus, and extend it to the insertion of the peroneus brevis tendon at the base of the fifth metatarsal• Open the sheath of the peroneus brevis tendon• Through the medial incision, create a tunnel posterior to the tibia and

anterior to the neurovascular bundle, directed laterally toward the fibula

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KLING, KAUFER, HENSINGER• Pass the free end of the tendon through the tunnel, ensuring that the

transferred tendon is posterior to the tibia and fibula and anterior to the neurovascular bundle and toe-flexor tendons to prevent neurovascular and flexor tendon compression during muscle contraction• Weave the end of the tendon through the peroneus brevis tendon,

and suture it to the tendon

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KLING, KAUFER, HENSINGER• Adjust tension on the transferred tendon so that the hindfoot is in

neutral with the ankle in neutral dorsiflexion• If the Achilles tendon was lengthened with a Z-plasty, repair it at this

time• Close the wounds in routine fashion, and apply a long-leg cast with

the knee slightly flexed and the foot in neutral

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Split Anterior Tibial Tendon Transfer

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HOFFER ET AL.• Three incisions are used for the split anterior tibial tendon transfer• With the patient supine, make the first incision medially over the

anterior tibial insertion on the medial cuneiform and first metatarsal

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HOFFER ET AL.• Identify the anterior tibial tendon, protecting the dorsalis pedis

artery, and split the tendon with an umbilical tape (Fig.)

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HOFFER ET AL.• Make a second incision over the anterior aspect of the leg at the

musculotendinous junction, and identify the anterior tibial tendon; pass the umbilical tape into the second incision (Fig.)

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HOFFER ET AL.• Identify the lateral half of the tendon, release it from its insertion,

and secure it with a locking stitch (Fig.), preserving as much length as possible, and then pass it into the second incision as well

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HOFFER ET AL.• Make the third incision on the foot over the dorsal aspect of the

cuboid• Pass the lateral half of the tendon subcutaneously into the third

incision, and close the first two incisions (Fig.)

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HOFFER ET AL.• Drill a hole into the cuboid, preserving a roof of bone• Pass the lateral slip of tendon through the drill hole, and suture it to

itself with nonabsorbable suture with the ankle in slight dorsiflexion and hindfoot eversion• If this is combined with lengthening of the Achilles tendon or

posterior tibial tendon recession, these procedures should be done before the anterior tibial tendon transfer• Carefully hold the foot in the corrected position during wound closure

and application of a short-leg cast

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Osteotomy of the Calcaneus

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Osteotomy of the Calcaneus• When the heel becomes fixed in varus, a corrective procedure on the

bone is required, combined with a muscle balancing soft tissue procedure• Osteotomy of the calcaneus as advocated by Dwyer corrects the

varus of the heel and, in contrast to a triple arthrodesis, does not impair mobility in the subtalar or midtarsal joints

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Osteotomy of the Calcaneus• Good long-term results have been reported after a modified Dwyer

calcaneal osteotomy (Silver et al.) • A minimum age of 3 years is recommended for this osteotomy• Triple arthrodesis is recommended in children 9 years old or older

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Osteotomy of the Calcaneus• Opening wedge osteotomies of the calcaneus are not recommended • The skin laterally and medially along the bone is only slightly mobile,

and opening wedges put tension on the suture line and tend to cause incisional skin sloughs• The medial calcaneal nerves also may be stretched by an opening

wedge osteotomy made from the medial side, causing painful neuromas

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Osteotomy of the Calcaneus• For these reasons, a closing wedge resection osteotomy of the

calcaneus is recommended• For varus deformities, the incision is lateral and the base of the

wedge of bone removed is lateral

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Calcaneal Osteotomy (DWYER)• Expose the lateral aspect of the foot through a curved incision parallel

and about 1 cm posterior and inferior to the peroneus longus tendon (Fig.)

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Calcaneal Osteotomy (DWYER)• Retract the superior wound edge until the tendon sheath of the

peroneus longus is exposed• Strip the periosteum from the superior, lateral, and inferior surfaces

of the calcaneus posterior to this tendon

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Calcaneal Osteotomy• Remove a wedge of bone from the calcaneus just inferior and

posterior to the tendon and parallel with it • Make the base of the wedge 8 to 12 mm wide as needed for

correction of the deformity, and taper the wedge medially to, but not through, the medial cortex of the calcaneus

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Calcaneal Osteotomy• Manually break the medial cortex, and close the gap in the bone• Bring the bony surfaces snugly together by pressing the foot into

dorsiflexion against the pull of the Achilles tendon

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Calcaneal Osteotomy• Failure to close the gap in the calcaneus indicates that a small piece

of bone has been left behind at the apex of the wedge and should be removed• Ensure that the varus deformity has been corrected, and that the heel

is in the neutral or a slightly varus position• Close the wound, and apply a cast from the toes to the tibial

tuberosity

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THANK YOU

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