What is the treatment for a hamstring tear and avulsion fracture?

Treatment of Hamstring Tear and Avulsion Fracture

Surgical repair is the treatment of choice for displaced hamstring avulsion fractures, as early intervention reduces the risk of additional injury and improves functional outcomes.

Diagnosis and Assessment

• MRI is the gold standard imaging modality for evaluating hamstring injuries with avulsion fractures, providing detailed visualization of:

  • Extent of tendon tear
  • Degree of displacement
  • Associated soft tissue injuries 1
  • Bone marrow edema

• CT may be used to determine:

  • Fracture extent
  • Displacement
  • Comminution
  • Intra-articular extension 1

Treatment Algorithm

Conservative Management (for minimally displaced avulsions)

Indicated for:

• Non-displaced or minimally displaced (<2 cm) avulsion fractures
• Low functional demands
• Medical contraindications to surgery

Components:

1. Initial period of rest and protection (2-3 weeks)
2. Ice for pain control and reduction of swelling 1
3. NSAIDs for pain management 1
4. Progressive rehabilitation program focusing on:
   • Gradual restoration of range of motion
   • Progressive strengthening exercises
   • Flexibility training 2

Surgical Management

Indicated for:

• Displaced avulsion fractures (>2 cm)
• Athletes or physically active individuals
• Failed conservative management

Timing:

• Early surgical intervention is preferred (within 3 months of injury) to prevent additional tissue damage 1, 3
• Delayed presentation may require more extensive surgery and has less favorable outcomes 3

Surgical options:

1. Open reduction and internal fixation (ORIF) with cannulated screws for avulsion fractures 4
2. Direct tendon repair to bone for pure tendon avulsions 5

Post-Surgical Rehabilitation

Traditional Approach

• Post-operative bracing with limitation of hip flexion and knee flexion
• Gradual return to weight-bearing
• Progressive rehabilitation program

Advanced Approach

• Consideration of chemoprotection with botulinum toxin injections to:
  • Reduce muscle spasm
  • Minimize need for cumbersome bracing
  • Allow controlled motion during physical therapy 6
  • Potentially reduce risk of re-injury

Rehabilitation Protocol

Phase 1 (0-4 weeks):

• Protected weight-bearing
• Limited range of motion
• Gentle isometric exercises

Phase 2 (4-8 weeks):

• Progressive range of motion exercises
• Initiation of eccentric strengthening
• Core stability training

Phase 3 (8-16 weeks):

• Progressive resistance training
• Sport-specific exercises
• Running progression

Phase 4 (16+ weeks):

• Return to sport-specific activities
• Continued strengthening and flexibility training

Return to Activity

• Full return to previous level of activity typically takes 6-8 months
• Criteria for return:
  • Symmetric knee and hip range of motion
  • Restored strength (>90% compared to unaffected side)
  • Absence of pain with activity
  • Successful completion of sport-specific functional tests 6

Pitfalls and Caveats

1. Delayed diagnosis is common and leads to:

   • More extensive surgical procedures
   • Prolonged recovery time
   • Poorer functional outcomes 3

2. Inadequate rehabilitation following initial injury often leads to:

   • Recurrent injuries
   • Chronic pain
   • Decreased performance 2

3. Return to activity before complete rehabilitation increases risk of re-injury 2

4. Surgical repair of chronic avulsions (>3 months) is technically more challenging but can still yield good results 5, 3