Is an extension brace better after an acute Anterior Cruciate Ligament (ACL) injury?

Extension Brace After Acute ACL Injury: Evidence-Based Recommendations

Functional support with an extension brace is preferred over immobilization for acute ACL injuries, as it provides better outcomes for pain control and stability while allowing appropriate healing and rehabilitation. 1

Benefits of Extension Bracing for Acute ACL Injury

Extension bracing after an acute ACL injury offers several important benefits:

• Controls knee hyperextension, which is critical for protecting the healing ACL 1
• Reduces excessive valgus motion of the knee joint 2
• Provides subjective stability and confidence during the acute phase 1
• Allows for immediate knee mobilization within a controlled range 1
• Permits early weight-bearing activities while maintaining protection 1

Brace Selection and Application

When selecting an extension brace for acute ACL injury:

1. Type of brace: Choose a functional brace with extension limitation capability

   • Functional "hinge-post-shell" designs provide improved tibial-displacement control and greater rigidity 1
   • Setting 10-20 degrees of extension limitation helps minimize hyperextension of the knee joint 1

2. Fitting considerations:

   • Select the longest brace that comfortably fits the patient's leg for optimal protection 1
   • Ensure correct hinge placement relative to the femoral condyles for optimal performance 1
   • Regular tightening of straps helps reduce unwanted brace migration 1

Duration of Bracing

• Functional support should be used for 4-6 weeks following the acute ACL injury 1
• After this initial period, transition to rehabilitation exercises should be prioritized 1

Exercise Protocol with Bracing

While using the extension brace:

• First 4 weeks: Prioritize closed kinetic chain exercises to reduce risk of patellofemoral pain 1
• After 4 weeks: Open kinetic chain exercises (90-45°) can be added 1
  • For hamstring grafts (if reconstruction performed): avoid extra weight in first 12 weeks 1
• Neuromuscular training should be incorporated throughout rehabilitation 1

Brace Design Considerations

Research shows differences between brace designs:

• Rigid braces:

  • More effective at limiting tibial rotation and anteroposterior translation 1
  • May cause extension deficit during gait 2
  • Can increase transverse plane range of motion 2

• Soft braces:

  • Provide adequate limitation of peak abduction with less impact on normal gait 2
  • May offer better proprioceptive benefits 3
  • Show significant decrease in knee joint laxity (33% vs 14% for rigid braces) 3

Common Pitfalls to Avoid

1. Prolonged immobilization: Avoid complete immobilization beyond 10 days as it leads to worse outcomes compared to functional support and exercise 1

2. Overreliance on bracing alone: Bracing should complement, not replace, appropriate rehabilitation exercises 1

3. False sense of security: Patients may develop overconfidence with bracing, potentially leading to risky activities before healing is complete 1

4. Improper fit: Poorly fitted braces can migrate during use, reducing effectiveness and potentially causing skin irritation 1

5. Delayed rehabilitation: Even with bracing, early mobilization and appropriate exercises are essential for optimal outcomes 1

Monitoring and Follow-up

• Regular assessment of brace positioning and structural integrity is essential 1
• Replace damaged braces immediately to ensure maximum functionality 1
• Monitor for skin irritation, which can be more common with certain brace types 1

Extension bracing provides valuable support during the acute phase of ACL injury, but should be viewed as one component of a comprehensive rehabilitation approach that includes appropriate exercise therapy and gradual return to activity.