Technique of genu valgum correction with growth modulation

Dr Taral V Nagda

Institute of Paediatric Orthopaedic Disorders
 www.ipodindia.org
taralnagda@gmail.com

E plate hemiepiphysiodesis is a modern method to correct the deformities of long bones in a growing child. It works on the principle that controlling the growth on one side of growth plate results in angulation on the opposite side.

In presence of deformity the growth modulation on the convex side/ apical side can result in slow controlled correction of the deformity. The advantages of such a procedure will be

• No need of immobilisation or plaster as the bone is not cut
• Earlier mobilisation and return to activities
• Slow and safe correction
• The growth resumes normally after plate removal hence can be done even at younger age
• Timing of surgery not important as long as atleast 1 year available for corection before the growth stops.

Indications

• Correcting angular deformity in a growing child with open physis

Prerequisites

• 1 year of growth remaining
• One plane deformity frontal sagital oblique
• Growth potential on opposite side

Contraindications

• Closed Physis
• Skeletal Maturity
• Physiological Deformities

Case Study

8 yr old girl with renal osteodystrophy with genu valgum shows excellent correction in 1 year

Equipments needed

• C ARM
• Radiolucent table
• 1mm and 1.5 mm guide wires
• E plate
• 5mm self tapping cannulated screws (15-30mm)
• Stop Drill

Surgical steps

Step 1 : LOCALIZATION OF PHYSIS

• Under image intensifier 1.5 mm guide wire is passed at the center of physis
• Confirmed in both AP & Lat views

Step 2: SKIN INCISION

• About 1.5 cm centered over guide wire
• The incision is deepened till perichomdrium
• E plate is positioned with its central hole sliding over the guide wire over the perichondrium
• The plate should be along the midline of the bone axis on lateral view

Step 3 GUIDE WIRES

• 2 guide wires are passed  through the holes on either sides of the physis
• They  need not be parallel but  care should be taken is not to violate the physis

Step 4 SELF TAPPING CANNULATED SCREWS

• Screw length is measured
• Should not be too short
• Generally 15-30 mm screws are sufficient
• Cortex is drilled
• Self tapping screws are passed

Step 5 Closure and Dressing

The closure is done in layers and compression dressing is applied.

No cast or immobilization is needed

Full weight bearing supported walking and knee mobilization are started the next day

Post op Protocol

• Day care surgery
• No immobilisation
• Immediate mobilisation
• Xrays once in 3 months
• Implant removal once the deformity is corrected

Advantages of E plate over staples

• Flexibility
• Unconstrained implant
• Load sharing
• One plate per physis
• Fully threaded cannulated screws resist pull-out forces
• Diverging screws function like a hinge to gently guide natural growth
• Easy to remove