Mehta / EDF Casting (Elongation-Derotation-Flexion)

Attire

Size 8 gloves · gown per casting setup.

Anesthesia

General anesthesia (airway secured). Anticipate improved ventilation after traction release / towel removal.

Equipment

• Mehta (EDF) casting table with traction capability.
• Head halter + pelvic traction straps; lower-extremity halters (hip flexion).
• Silver-impregnated casting shirt (undergarment).
• Webril 4" padding; plaster of Paris 4" rolls; fiberglass tape 3–4" (white + 1 colored).
• Cast saw, duckbill flaring tool, trimming instruments. Clothespin/clamp (elevate axillary shirt). Moleskin (PACU petaling).

Positioning

• Supine on Mehta table. Upper bar at mid-thoracic / scapular level; lower bar at pubic symphysis (small spike at sacrum level).
• Gentle head traction (elongation); pelvic traction at iliac-crest level; LE halters for hip flexion (reduce lumbar lordosis).
• Lower table/mattress for 360° circumferential access.

Technique pearls

• Undergarment: silver-impregnated shirt, smooth into axillae, elevate axillary portion off skin.
• Padding: 3 circumferential Webril layers, axilla→pubic symphysis, 50% overlap, wrinkle-free; extra folded Webril over iliac crests.
• POP layering: 4 layers at pubis → cephalad 50% overlap (≈2 mid-trunk) → 4 layers at axilla → reverse caudad (≈+2 mid) = ~4 uniform layers. Apply slightly snug (not tight) to prevent pistoning.
• Pelvic mold: ulnar border / broad palm, gentle waist indentation just above iliac crests, no thumb impressions.
• Derotation (e.g., left curve): surgeon on convex side; P→A force on posterior rib prominence, A→P counterforce contralateral chest; 3rd assistant A→P on ipsilateral shoulder. Avoid heavy anterior rib pressure (iatrogenic rib deformity).
• Fiberglass overwrap: 3 layers inferior border → cephalad 50% overlap (≈2 mid) → 3 layers superior; finish 1 colored layer, end roll mid-cast (not at superior edge).
• Release traction after fiberglass sets; remove folded towels beneath cast (improves ventilation).

Trimming & windowing

• Inferior: trim to pubic symphysis, confirm hip flexion ~100°; duckbill-flare posterior-inferior edge for diaper.
• Superior/axilla: assess arms adducted, pull shoulders down; trim to avoid axillary impingement/skin pinch.
• Anterior window: xiphoid ≈ antecubital fossa when arm adducted; cut hourglass / figure-of-eight (rib margins stay covered; leave ~2 fingerbreadths sup/inf).
• Posterolateral rib-expansion window: D-shaped window on concave-rib side (e.g., right for left curve).

Final check

Comfortable breathing; no axillary/groin impingement at hip flexion; smooth padded edges; flare posteriorly/inferiorly + within anterior window for rib expansion. PACU: petal edges with moleskin.

References

Welborn/Sanders/D'Astous, *Evolution of EDF Casting*, JPOSNA 2021 · Mehta MH, JBJS(Br) 2005 · POSNA Academy Video Abstract 8A.