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
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
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
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
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
Neuromuscular PlanovalgusBiomechanics
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)
Neuromuscular PlanovalgusExtra-Articular Arthrodesis
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%
Neuromuscular PlanovalgusExtra-Articular Arthrodesis
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
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)
Subtalar Staple Arthroereisis
CONCLUSIONS
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
Neuromuscular PlanovalgusSubtalar Staple Arthroereisis
THANK YOU
Dr. Donald W. Kucharzyk