The Surgical Treatment of Neuromuscular Planovalgus “The Role of Staple Arthroereisis” Dr. Donald W. Kucharzyk The Orthopaedic, Pediatric & Spine Institute

The Surgical Treatment of Neuromuscular Planovalgus “The Role of Staple Arthroereisis”

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

Neuromuscular PlanovalgusSevere 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

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


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


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

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 MidfootProduces a Rocker Bottom Foot with

Valgus Hindfoot and Abducted Forefoot


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


To Correct This Deformity, we must Address all aspects due to the altered biomechanics

Calcaneus Placed Beneath the TalusReduction of the Hindfoot EquinusMuscle Balance Must be PresentAvoidance of Varus HindfootBest Achieved while Foot is Supple and not

Fixed with Secondary Changes

Neuromuscular PlanovalgusEtiology

Seen in A Variety of Paralytic DisordersUpper Motor Neuron lesions producing

SpasticityLower Motor Neuron lesionsFlaccid ParalysisCerebral PalsyMyelodysplasiaPoliomyelitis

Neuromuscular PlanovalgusTreatment Options

NONOPERATIVE OrthoticsOPERATIVE Subtalar Stabalization

Neuromuscular PlanovalgusNonOperative Treatment

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

Neuromuscular PlanovalgusOperative Treatment

Subtalar Extra-articulat Arthrodesis (Grice)

Batchelor Subtalar ArthrodesisDennyson-Fulford Stabalization

(Princess Margaret Rose)StayPeg Procedure(Millar)Calcaneal OsteotomiesTriple Arthrodesis

Neuromuscular PlanovalgusExtra-Articular Arthrodesis

Preserves the Talonavicular and Calcaneocuboid Joints

Corrects Valgus deformity of HindfootRestores Longitudinal Arch HeightDoes Not Correct Fixed DeformityCan Produce loss of Lateral Mobility of the

HindfootMust Address Hindfoot Equinus (leading

cause of failure)


Variable Success Rates reported (50-85%)

Tohen (JBJS 1969) 76%Banks (CORR 1977) 76%Ross & Lyne (CL.OR. 1980) 64% failureBleck (1987) 50% failureDvrark (1989) 94%


Reasons for Failure

Persistant ankle valgus Nonunion Migration of the Graft Ankle Varus

Neuromuscular PlanovalgusBatchelor Subtalar Arthodesis

Does not Expose the Subtalar JointInsert 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

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

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

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

Neuromuscular PlanovalgusSubtalar StayPeg Arthrorisis

Corrects heel ValgusEliminates Abnormal PronationIncreased Medial Longitudinal ArchPrevents forward movement of TalusAllows readaptation of the foot via

secondary bone and soft tissue changes

Neuromuscular PlanovalgusSubtalar StayPeg Arthrorisis

92% success rate at 4 years (CORR 1983)

No Major ComplicationsLow Incidence of the need for

Mechanical Support PostOpOnly Risk is Dislodgement of Stay

Peg

Neuromuscular Planovalgus

A NEW PROCEDURE SUBTALAR STAPLE ARTHROEREISISEliminates the need for Subtalar

Arthrodesis in a Young ChildEliminates the need to insert a screw or

graft across neck of talusProduces predictable correction and

resultsDelays Arthrodesis till Older Age

Subtalar Staple ArthroeresisBiomechanical and FunctionalStabalizes the Subtalar JointsRequires a Supple FootRequires the Equinus to be corrected

prior to the ProcedureBest Suited for Children less than Six

years of ageContraindicated when forefoot can’t

be placed plantigrade when hindfoot placed in neutral position

Subtalar Staple ArthroereisisTechnique

Lateral Arm of the Cincinnati IncisionTalocalcaneal Subluxation is corrected

via release anterior, lateral and posterior articulations of subtalar joint

Calcaneus reduced and held in placeEquinus evaluated and correctedVitallium Staple placed across joint with

foot in 15 degrees of plantar flexion

Subtalar Staple ArthroereisisClinical StudyCincinnati Children’s Hospital20 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 AssessmentComplications

Subtalar Staple ArthroereisisRadiographic AssessmentLoss of Correction/Loss Talocalcaneal

AngleDivided into Excellent, Good, Fair and PoorExcellent: less than 5 degree lossGood: 5-10 degree lossFair: over 10 degree lossPoor: over 10 degree loss and worse than preop

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

Subtalar Staple ArthroereisisRadiographic Results

Excellent: 15 (48%)Good: 11 (36%)Fair: 2 ( 6%)Poor: 3 (10%) EXCELLENT-GOOD RESULT: 84% FAIR- POOR: 16% Bank’s Criteria ( CORR 1977 )

Subtalar Staple ArthroereisisComplications

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

Subtalar Staple ArthroereisisRecent Additional Study

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

Subtalar Staple ArthroereisisRecent Additional Study

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

Subtalar Staple Arthroereisis

CLINICAL CASE

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


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)

Subtalar Staple Arthroereisis

CONCLUSIONS


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

Neuromuscular PlanovalgusSubtalar Staple Arthroereisis

THANK YOU

Dr. Donald W. Kucharzyk

Documents

The Surgical Treatment of Neuromuscular Planovalgus “The Role of Staple Arthroereisis” Dr. Donald W. Kucharzyk The Orthopaedic, Pediatric & Spine Institute