What type of cast is recommended for a midshaft radius fracture?

Cast Selection for Midshaft Radius Fractures

For midshaft radius fractures, a long-arm cast is the recommended initial immobilization method, especially for displaced fractures requiring closed reduction. 1

Initial Management

• Midshaft radius fractures typically result from a fall onto an outstretched hand and require proper immobilization to ensure adequate healing 1
• For nondisplaced or minimally displaced fractures, initial immobilization should be with a sugar-tong splint, followed by conversion to a short-arm cast for a minimum of three weeks 1
• For fractures with significant displacement (>3mm) or angulation (>10°), proper reduction followed by more rigid immobilization is necessary 2

Cast Selection Based on Fracture Characteristics

• For displaced midshaft radius fractures:

  • Initial immobilization with a long-arm cast provides better control of forearm rotation and helps maintain reduction 1
  • After initial healing (typically 3-4 weeks), conversion to a short-arm cast may be appropriate 3

• For stable, minimally displaced fractures:

  • Short-arm casting may be sufficient, particularly in older patients (>55 years) where it has been shown to be as effective as long-arm casting while causing less disability and shoulder discomfort 3

Duration of Immobilization

• Traditional immobilization period for radius fractures is 6 weeks 4
• Recent evidence suggests that 4 weeks of immobilization may be sufficient for adequately reduced distal radius fractures, with similar functional outcomes and complication rates compared to 6 weeks 4
• Radiographic follow-up is recommended at approximately 3 weeks and at the time of immobilization removal to confirm adequate healing 2

Special Considerations

• Combined fractures involving both the radius and ulna generally require surgical fixation rather than casting alone 1
• For pediatric patients, acceptable angulation parameters differ based on age, with greater remodeling potential in younger children 5
• Monitor for potential complications such as:
  • Median nerve injury, which can complicate distal radius fractures 1
  • Skin irritation and muscle atrophy, which occur in approximately 14.7% of immobilization cases 2
  • Joint stiffness, which can be minimized through appropriate active finger motion exercises during the immobilization period 2

Follow-up Protocol

• Initial radiographs to confirm diagnosis and fracture pattern 2
• Follow-up radiographs between 1-2 weeks after initial reduction to detect early loss of reduction 5
• Additional imaging at approximately 3 weeks and at the time of cast removal 2
• Consider earlier transition from long-arm to short-arm immobilization after initial healing phase (3-4 weeks) to improve patient comfort while maintaining fracture stability 3