The Surgical Treatment of Neuromuscular Planovalgus

1
The Surgical Treatment of
Neuromuscular Planovalgus
The Role of Staple Arthroereisis

• Dr. Donald W. Kucharzyk
• The Orthopaedic, Pediatric
• Spine Institute
• Crown Point, Indiana

2
Neuromuscular Planovalgus

• Severe PlanoValgus of the Foot in a Neuromuscular
  Child is a Complicated Matter to Treat
• Altered Biomechanics and Secondary Changes can
  occur
• Biomechanical Changes occur in the Subtalar Joint
  and Midfoot
• Secondary Changes include Altered Gait, Genu
  Recurvatum and Plantar Callous

3
Neuromuscular PlanovalgusFunctional Anatomy

• To Understand Planovalgus we need to look at the
  Functional Concepts of the Subtalar Joint
• From a Functional Standpoint the Subtalar Joint
  is a Single Axis
• The Axis of Rotation Averages 41 deg. To the
  Horizontal and 23 deg. To the Midline of the Foot

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Neuromuscular PlanovalgusFunctional Anatomy

• This Allows the Foot in Stance to Absorb the
  Torsion of the Tibial
• The Hindfoot Everts allowing the Talonavicular
  and Calcaneocuboid Joints to become Parallel
  giving free Motion to the Mid and Fore Foot
• Weightbearing Forces are Transmitted Medial to
  the Calcaneous

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Neuromuscular PlanovalgusFunctional Anatomy

• Mild Pronation in the Forefoot allows even
  Distribution of Weight on the Plantar Surface of
  the Foot
• Valgus Positioning of the Hindfoot allows the
  Center of Gravity to Pass over the Subtalar Joint
  easily
• Varus Positioning, on the other hand, Results in
  a Semi-Rigid Foot with Abnormal Gait Pattern

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Neuromuscular PlanovalgusBiomechanics

• In a Neuromuscular Child, the Deformity is
  Produced through a Combination of Spasticity,
  Weakness, and Altered Motion during Gait
• Equinus in the Hindfoot prevents Normal
  Dorsiflexion
• Shifts Dorsiflexion to the Midfoot
• Produces a Rocker Bottom Foot with Valgus
  Hindfoot and Abducted Forefoot

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Neuromuscular PlanovalgusBiomechanics

• The Talus assumes a more Vertical and Medial
  Position
• The Calcaneus rotated Posterolaterally from its
  Normal Position
• Sustentaculum Tali loses its Supporting Position
  beneath the Neck of the Talus as the Calcaneus
  Subluxes Laterally
• Posterior Tibialis loses its Function adding to
  the Planovalgus Deformity

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Neuromuscular PlanovalgusBiomechanics

• To Correct This Deformity, we must Address all
  aspects due to the altered biomechanics
• Calcaneus Placed Beneath the Talus
• Reduction of the Hindfoot Equinus
• Muscle Balance Must be Present
• Avoidance of Varus Hindfoot
• Best Achieved while Foot is Supple and not Fixed
  with Secondary Changes

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Neuromuscular PlanovalgusEtiology

• Seen in A Variety of Paralytic Disorders
• Upper Motor Neuron lesions producing Spasticity
• Lower Motor Neuron lesions
• Flaccid Paralysis
• Cerebral Palsy
• Myelodysplasia
• Poliomyelitis

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Neuromuscular PlanovalgusTreatment Options

• NONOPERATIVE
• Orthotics
• OPERATIVE
• Subtalar Stabalization

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Neuromuscular PlanovalgusNonOperative Treatment

• UCBL orthosis with medial wedge
• limited if equinus present as it
• will exaggerate midfoot collapse
• during gait
• SMO when equinus and valgus
• deformity are marked and
• talus plantarflexed into vertical
• position

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Neuromuscular PlanovalgusOperative Treatment

• Subtalar Extra-articulat Arthrodesis (Grice)
• Batchelor Subtalar Arthrodesis
• Dennyson-Fulford Stabalization (Princess Margaret
  Rose)
• StayPeg Procedure(Millar)
• Calcaneal Osteotomies
• Triple Arthrodesis

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Neuromuscular PlanovalgusExtra-Articular
Arthrodesis

• Preserves the Talonavicular and Calcaneocuboid
  Joints
• Corrects Valgus deformity of Hindfoot
• Restores Longitudinal Arch Height
• Does Not Correct Fixed Deformity
• Can Produce loss of Lateral Mobility of the
  Hindfoot
• Must Address Hindfoot Equinus (leading cause of
  failure)

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Neuromuscular PlanovalgusExtra-Articular
Arthrodesis

• Variable Success Rates reported (50-85)
• Tohen (JBJS 1969) 76
• Banks (CORR 1977) 76
• Ross Lyne (CL.OR. 1980) 64 failure
• Bleck (1987) 50 failure
• Dvrark (1989) 94

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Neuromuscular PlanovalgusExtra-Articular
Arthrodesis

• Reasons for Failure
• Persistant ankle valgus
• Nonunion
• Migration of the Graft
• Ankle Varus

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Neuromuscular PlanovalgusBatchelor Subtalar
Arthodesis

• Does not Expose the Subtalar Joint
• Insert Fibular Graft from the Neck of the Talus
  across the sinus tarsi into the Calcaneus with
  Neutral Hindfoot
• Brown (JBJS 1968) 17 out of 20 patients had
  stability with survival of the graft at 4 years

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Neuromuscular PlanovalgusBatchelor Subtalar
Arthrodesis

• Seymour and Evans (JBJS 1958) reason for success
  simplicity of insertion and retention, fixation
  of the foot after insertion of the graft is
  stable
• Hsu, Yau, Obrien and Hodgson (JBJS 1972)
  complication of the procedure being late
  development of ankle valgus

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Neuromuscular PlanovalgusDennyson-Fulford
Stabalization

• Cortical screw inserted into the talar neck and
  laterally into the calcaneus
• Sinus Tarsi denuded and decorticated and grafted
• Maintains correction of the deformity with rapid
  fusion

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Neuromuscular PlaniovalgusDennyson-Fulford
Stabalization

• Reported Fusion Success Rates of 94 (JBJS 1976)
• Barrasso (JPO 1984) 95 fusion success rates
• DeLuca (1990) similar fusion rates of 94-95
  with the use of allograft

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Neuromuscular PlanovalgusSubtalar StayPeg
Arthrorisis

• Corrects heel Valgus
• Eliminates Abnormal Pronation
• Increased Medial Longitudinal Arch
• Prevents forward movement of Talus
• Allows readaptation of the foot via secondary
  bone and soft tissue changes

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Neuromuscular PlanovalgusSubtalar StayPeg
Arthrorisis

• 92 success rate at 4 years (CORR 1983)
• No Major Complications
• Low Incidence of the need for Mechanical Support
  PostOp
• Only Risk is Dislodgement of Stay Peg

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Neuromuscular Planovalgus

• A NEW PROCEDURE
• SUBTALAR STAPLE ARTHROEREISIS
• Eliminates the need for Subtalar Arthrodesis in a
  Young Child
• Eliminates the need to insert a screw or graft
  across neck of talus
• Produces predictable correction and results
• Delays Arthrodesis till Older Age

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Subtalar Staple ArthroeresisBiomechanical and
Functional

• Stabalizes the Subtalar Joints
• Requires a Supple Foot
• Requires the Equinus to be corrected prior to the
  Procedure
• Best Suited for Children less than Six years of
  age
• Contraindicated when forefoot cant be placed
  plantigrade when hindfoot placed in neutral
  position

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Subtalar Staple ArthroereisisTechnique

• Lateral Arm of the Cincinnati Incision
• Talocalcaneal Subluxation is corrected via
  release anterior, lateral and posterior
  articulations of subtalar joint
• Calcaneus reduced and held in place
• Equinus evaluated and corrected
• Vitallium Staple placed across joint with foot in
  15 degrees of plantar flexion

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Subtalar Staple ArthroereisisClinical Study

• Cincinnati Childrens Hospital
• 20 patients (31 feet)
• Spastic Planovalgus (CP and Myelo)
• Followup was on average 4 years (2 to7)
• Radiographic evaluation included lateral
  talocalcaneal angle (preop, postop, and recent
  followup)
• Clinical, Radiographic Assessment
• Complications

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Subtalar Staple ArthroereisisRadiographic
Assessment

• Loss of Correction/Loss Talocalcaneal Angle
• Divided into Excellent, Good, Fair and Poor
• Excellent less than 5 degree loss
• Good 5-10 degree loss
• Fair over 10 degree loss
• Poor over 10 degree loss and
• worse than preop

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Subtalar Staple ArthroereisisRadiographic Results

• PreOp Talocalcaneal Angle 50 degrees
• ( Range was from 32 deg. To 65 deg.)
• PostOp Talocalcaneal Angle 32 degrees
• ( Range was from 3 deg. To 44 deg.)
• Average Amount of Correction was 18 degrees

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Subtalar Staple ArthroereisisRadiographic Results

• Excellent 15 (48)
• Good 11 (36)
• Fair 2 ( 6)
• Poor 3 (10)
• EXCELLENT-GOOD RESULT 84
• FAIR- POOR 16
• Banks Criteria ( CORR 1977 )

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Subtalar Staple ArthroereisisComplications

• MINOR
• Breakdown of Wound 1
• Superficial Infection 1
• MAJOR
• Migration of Staple 1

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Subtalar Staple ArthroereisisRecent Additional
Study

• 10 patients (14 feet)
• Spastic Cerebral Palsy
• Follow-up 2 plus 3 years (2 to 7)
• Radiographic Results
• Preop angle 55 deg.
• Postop angle 32 deg.
• Average Correction 20 deg.

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Subtalar Staple ArthroereisisRecent Additional
Study

• Radiographic Results
• Excellent-Good 85
• Fair-Poor 15
• Complications
• Prominence of Staple 1

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Subtalar Staple Arthroereisis

• CLINICAL CASE

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Subtalar Staple ArthroereisisConclusions

• Suitable for Stabalization of the planovalgus
  foot in Children less than Six years of age
• Stabalizes the joint while Secondary Adaptive
  Changes Occur (osseous and soft tissue)
• Delayed and Eliminated the need for Osseous
  Fusion of the Growing Foot

34
Subtalar Staple ArthroereisisConclusions

• Comparing these results to Various Authors
  results of subtalar arthrodesis
• Arthrodesis Arthroereisis
• Excellent-Good 70.9 84
• Fair-Poor 29.1 16
• Complications 27 1
• ( valgus, varus, nonunion, graft migration)

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Subtalar Staple Arthroereisis

• CONCLUSIONS

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Subtalar Staple ArthroereisisConclusions

• An Excellent Procedure for the Management of
  Subtalar Instability in the Young Child who has
  Severe Talocalcaneal Subluxation secondary to
  Neuromuscular Imbalance

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Neuromuscular PlanovalgusSubtalar Staple
Arthroereisis

• THANK YOU
• Dr. Donald W. Kucharzyk