How do I immobilize a partial Achilles tendon rupture?

Immobilization of Partial Achilles Tendon Rupture

For partial Achilles tendon rupture, immobilize with a protective device that limits dorsiflexion for 2-4 weeks, followed by early protected weight bearing to optimize recovery while preventing rerupture. 1, 2

Initial Immobilization Approach

1. First 2-4 weeks:

   • Use a splint or modified cast device that specifically limits dorsiflexion to protect the tendon 1
   • Position the ankle in slight plantar flexion (equinus position) to reduce tension on the Achilles tendon 2
   • Ensure the immobilization device provides adequate equinus positioning - equinus casts achieve better ankle positioning than rigid boots with heel wedges 3

2. Weight bearing protocol:

   • Begin early protected weight bearing within the first 2 weeks 1
   • Use crutches initially to assist with partial weight bearing
   • Gradually increase weight bearing as tolerated while maintaining protection of the tendon

Device Selection

Choose from one of these immobilization options:

• Equinus cast - Provides superior ankle positioning in plantar flexion (average 136° tibiotalar angle) 3
• Walking boot with heel wedges - More convenient but achieves less equinus (average 124° tibiotalar angle) 3
• Custom orthosis - May address biomechanical factors like foot pronation or heel varus 2

Rehabilitation Timeline

1. Weeks 0-2: Complete immobilization in equinus position
2. Weeks 2-4: Begin protected weight bearing with immobilization device
3. Weeks 4-6: Progress to full weight bearing in protective device
4. Weeks 6-8: Begin gentle range of motion exercises while continuing protection
5. Weeks 8-12: Start eccentric strengthening exercises - the most effective conservative treatment 2

Additional Treatment Measures

• Apply ice therapy for pain management
• Consider NSAIDs for acute pain relief (short-term use only) 2
• Use heel lifts or orthoses to reduce tendon strain 2
• Wear open-backed shoes when transitioning from immobilization 2

Important Considerations and Pitfalls

• Avoid common pitfalls:

  • Misdiagnosis - most cases labeled "tendonitis" are actually degenerative tendinopathy 2
  • Corticosteroid injections directly into the tendon (increases rupture risk) 2
  • Prolonged immobilization (leads to muscle atrophy) 2
  • Overly aggressive early rehabilitation 2

• When to consider surgery:

  • Persistent partial ruptures not responding to 2-3 months of conservative treatment 2
  • Young, active patients and athletes may benefit from earlier surgical intervention 2, 4

• Recovery expectations:

  • Most patients (80%) fully recover within 3-6 months with proper conservative care 2
  • Return to sports activities typically occurs within 3-6 months 1

Remember that patient compliance with the immobilization protocol is crucial to prevent rerupture and ensure optimal healing 1. The combination of appropriate immobilization and early functional rehabilitation offers the best outcomes for partial Achilles tendon ruptures.