How long should a cast stay on for a fracture?

Duration of Cast Immobilization for Fractures

The optimal duration of cast immobilization for fractures depends on the fracture type, with most fractures requiring 4-6 weeks of immobilization, though shorter durations (1-2 weeks) may be appropriate for certain stable fractures followed by functional bracing.

Fracture-Specific Cast Duration Guidelines

Distal Radius Fractures

• Non-displaced or minimally displaced fractures:

  • 1 week of cast immobilization followed by gradually increasing wrist mobilization is safe and effective 1
  • Shows similar outcomes to traditional 3-5 weeks of immobilization with no significant differences in function, pain scores, or secondary displacement rates

• Displaced fractures after closed reduction:

  • 4 weeks of cast immobilization is safe and produces similar outcomes to 6 weeks 2
  • No clinically significant differences in Patient-Rated Wrist Evaluation scores, range of motion, or complications between 4 and 6 weeks of immobilization

Ankle Fractures

• Post-surgical ankle fractures:
  • 2 weeks of cast immobilization followed by 4 weeks of functional bracing produces similar outcomes to 6 weeks of continuous casting 3
  • No clinically significant differences in Olerud-Molander Ankle Scores at 12 weeks or 2 years
  • No difference in wound complications between early transition to bracing versus continued casting

Lateral Ankle Sprains

• Functional treatment is preferred over immobilization:
  • Use of functional support (braces) for 4-6 weeks is preferred over immobilization 4
  • If immobilization is needed for pain or swelling control, it should be limited to a maximum of 10 days 4
  • Ankle braces show greater benefits compared to other types of functional support 4

Considerations for Cast Duration

Balancing Immobilization and Function

• Excessive immobilization can lead to:

  • Joint stiffness
  • Muscle atrophy
  • Chronic pain
  • Complex regional pain syndrome in severe cases 5

• Immediate post-cast impairments include:

  • 40% deficit in forearm rotation
  • 50% reduction in wrist motions
  • Significant grip strength reduction (approximately 24% of unaffected side)
  • Changes in forearm and wrist circumference 6

Transition to Rehabilitation

• Exercise therapy should begin early following cast removal 4
• Manual joint mobilization combined with exercise therapy produces better outcomes than exercise therapy alone 4
• Directed home exercise programs should be implemented after the immobilization period to promote optimal recovery 7

Special Considerations

Surgical vs. Non-surgical Management

• For surgically treated fractures:
  • Early protected weight bearing (≤2 weeks) is recommended for surgically treated Achilles tendon ruptures 4
  • Use of a protective device that allows mobilization by 2-4 weeks postoperatively is suggested 4

Unstable Pelvic Fractures

• Hemodynamically stable patients can safely undergo early definitive pelvic fracture fixation within 24 hours post-injury 4
• For physiologically deranged polytrauma patients, definitive pelvic fracture fixation should be postponed until after day 4 post-injury 4

Common Pitfalls to Avoid

• Unnecessarily prolonged immobilization leading to stiffness and muscle atrophy
• Premature removal of cast for unstable fractures risking displacement
• Failure to transition to functional rehabilitation after cast removal
• Not monitoring for complications such as pressure sores, nerve compression, or complex regional pain syndrome

In summary, the trend in fracture management is moving toward shorter immobilization periods followed by functional rehabilitation, with evidence supporting that this approach provides similar or better outcomes compared to traditional longer immobilization periods.