Long Arm Cast

Other Names

Demonstration of the long arm cast

Illustration of the stockinette in the long arm cast

• Long Arm Cast

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Background

• This page describes the long arm cast
  • Often used in pediatric upper extremity casting
• Benefits over the short arm cast
  • Prevents pronation/ supination
  • Immobilizes the elbow
  • Prevents the cast from slipping down

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Indications

• Distal Radius Fracture
• Distal Ulna Fracture
• Pediatric forearm fractures
• Pediatric elbow dislocations

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Contraindications

• Absolute contraindications
  • None
• Relative contraindications
  • Most acute fractures
  • Open fractures
  • Injuries with neurovascular compromise

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Procedure

Equipment

• See: Casting materials

Technique

• Patient position
  • Keep the arm slightly extended past 90°
• Stockinette/ tubular bandage
  • Place proximal segment in axilla, extend over distal fingertips
  • Cut a hole for the thumb
• Cast padding
  • Wrap circumferentially from distal to proximal
  • Typically a single layer of padding is sufficient
  • Provide additional padding to bony prominences at the elbow including the condyles and olecranon
• There should be no creases in the stockinette or cast padding
• Cast material
  • Wrap from distal to proximal
  • Trim excess material to accommodate thumb and fingers
  • Fold the proximal and distal ends of the stockinette over the cast
  • Apply an additional layer of cast material
• Apply a 3 point fixation at the fracture site until the material hardens
• Arm should be supported in a shoulder sling
• Confirm neurovascular exam

Pearls and Pitfalls

• Avoid overstuffing the antecubital fossa
• Avoid creases in the antecubital fossa
  • Can apply padding/ taping at slightly flexed at 90°, then extend to slightly past 90°
• Care should be taken to ensure cast does not restrict flexion of MCP joints

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Aftercare

• Typically non-weight bearing until re-evaluated
• Advise patient to keep cast or splint clean and dry
• Do not insert objects into splint/ cast
• Monitor for complications (worsening pain, paresthesia/ numbness, color changes)
• Seek further care if unable to control pain at home

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Complications

• Acute Compartment syndrome
  • The ability to passively/actively extend fingers without discomfort indicates absence of muscle compartment compression
• Plaster burn/ thermal injury
• Pressure sores
• Nerve palsy
• Vascular compromise
• Splint dermatitis
• Permanent joint stiffness
• Skin infection
  • Cellulitis from underlying wound, pressure ulcers

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See Also

• Casting Main
• Procedures Main

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