Summary

Paediatric bone is soft and plastic. It can bend without snapping completely.

• Buckle (Torus) Fracture: Failure in Compression. The bone squashes down like a crushed can. STABLE. Needs Splint usually.
• Greenstick Fracture: Failure in Tension. One cortex snaps (tension side), the other cortex bends (compression side). UNSTABLE. Needs Cast + Molding. Distinguishing these two is the single most important decision in paediatric forearm trauma. [1,2,3]

Key Facts

• Why "Greenstick"?: If you try to snap a fresh green twig, it splinters on the outside but stays intact on the inside. Dead wood snaps cleanly (Adult fracture).
• The Cast Index: A round cast allows the arm to rotate. An oval cast (molded flat) prevents rotation. Width/Thickness ratio should be <0.8.
• Plastic Deformation: Sometimes the bone bends without breaking at all (Bow sign). This must be reduced or it limits rotation forever.

Clinical Pearls

"Buckle = Splint. Greenstick = Cast": A buckle fracture is inherently stable. It does not displace. A removable splint (Futura) for 3 weeks is fine. A Greenstick has potential to spring back to its deformed position due to the intact cortex acting as a spring. It needs a rigid CAST.

"Break the Cortex?": Debate exists. For severe greenstick fractures, some surgeons advocate intentionally snapping the intact cortex to stop it acting as a spring. This makes the fracture complete but "floppy" (easier to hold neutral).

                 PAEDIATRIC FOREARM #
                        ↓
                 X-RAY APPEARANCE
          ┌─────────────┼─────────────┐
        BUCKLE      GREENSTICK     COMPLETE
      (Bulging)     (Angulated)   (Both gone)
          |             |             |
       STABLE        UNSTABLE      UNSTABLE
          ↓             ↓             ↓
    VELCRO SPLINT    CAST/MUA      MUA/K-WIRE
      (3 weeks)      (6 weeks)     (6 weeks)

1. Buckle Fracture (Torus)

• Treatment: Removable Splint (Futura) or Soft Cast.
• Duration: 3 weeks.
• Outcome: Universally excellent. No follow-up X-ray needed.

2. Greenstick Fracture (Undisplaced)

• Definition: <10 degrees angulation.
• Treatment: Above Elbow Cast (if midshaft) or Below Elbow (if distal).
• Molding: Three-point mold to resist deformation.
• Duration: 4-6 weeks.

3. Greenstick Fracture (Displaced)

• Definition: >15-20 degrees angulation.
• Treatment: Manipulation Under Anaesthetic (MUA).
• Technique:
  • Apply traction.
  • Reverse the deformity (Over-correct).
  • Three-Point Mold cast (Interosseous mold).
• Surgery: Rarely needed unless unstable (K-wires).

The FORCE Study (2020)

• Comparison of Soft Bandage vs Splint vs Cast for Buckle Fractures.
• Result: Soft bandage/Splint was equivalent to Cast for pain and healing, but much more convenient. Changed practice to "No Cast for Buckles".

Is it a clean break?

No. Children's bones are like rubber or fresh branches.

• Buckle: It has squashed slightly. Like crumpling a coca-cola can. It is very stable.
• Greenstick: It has bent and cracked on one side, but is held together on the other. Like bending a fresh branch.

The Cast

• For Buckle: Just a velcro splint for comfort. Take it off to wash.
• For Greenstick: A proper fibre-glass cast is needed because the "branch" wants to spring back to its bent shape. We need to hold it straight until it hardens.

Healing time

Children heal incredibly fast. 3-4 weeks for a buckle, 6 weeks for a greenstick. They will be back on the monkey bars in 2 months.

Q1: Explain the "Three Point Mold". A: A casting technique used to hold a reduction.

1. Pressure point at the apex of the fracture (convexity).
2. Counter-pressure points proximal and distal (opposite side). This mechanical couple prevents the bone drifting back to its deformed position.

Q2: Why do Greenstick fractures have a high re-fracture rate? A: The intact cortex on the concave side is plastically deformed but not broken. It acts as a "spring", constantly exerting a force trying to return the bone to its angled position. If the cast is loose, the fracture slips.

Q3: Describe the FORCE Trial findings. A: The FORCE trial demonstrated that for distal radius Torus (Buckle) fractures, a soft bandage or removable splint offered equivalent pain relief and functional recovery compared to a rigid cast, with lower cost and fewer hospital visits.

(End of Topic)