What is the treatment approach for a full thickness Medial Collateral Ligament (MCL) tear?

Treatment Approach for Full Thickness MCL Tear

Conservative management with bracing and rehabilitation is the recommended first-line treatment for isolated full thickness MCL tears, with surgical intervention reserved only for cases with persistent instability after 6 weeks or those with multi-ligament injuries.

Diagnostic Evaluation

• Initial assessment should include:

  • Plain radiographs (anteroposterior and lateral views) to rule out associated fractures
  • Valgus stress testing at 30° of knee flexion to assess degree of instability
  • MRI is the gold standard for confirming diagnosis and evaluating associated injuries 1

• Ultrasound is a viable alternative with high accuracy:

  • 79% sensitivity, 98% specificity, and 95% accuracy for full-thickness MCL tears
  • Dynamic valgus stress ultrasound improves sensitivity to 96% 1

Treatment Algorithm

Conservative Management (First-Line)

1. Acute Phase (0-2 weeks):

   • Hinged knee brace locked at 30° flexion
   • Weight-bearing as tolerated with crutches
   • Ice, elevation, and anti-inflammatory medications
   • Early range of motion exercises within brace constraints

2. Intermediate Phase (2-6 weeks):

   • Progressive unlocking of brace as pain allows
   • Gradual increase in range of motion exercises
   • Begin strengthening exercises focusing on quadriceps and hamstrings
   • Discontinue crutches when gait is normalized

3. Advanced Phase (6-12 weeks):

   • Wean from brace (typically at 6 weeks)
   • Progressive strengthening and proprioceptive training
   • Sport-specific exercises and functional training

Surgical Management

Surgical intervention is indicated for:

• Persistent valgus instability after 6 weeks of conservative treatment
• Grade III tears with concomitant ACL or PCL injuries
• Avulsion injuries with displaced bone fragments
• Multi-ligament knee injuries

Surgical Options:

1. Primary repair: For acute avulsion injuries or tears at femoral/tibial attachment
2. Reconstruction: For chronic injuries or mid-substance tears with poor tissue quality

Evidence and Considerations

The literature demonstrates that most isolated MCL tears, even complete ones, heal well with conservative treatment 2. This is due to the MCL's excellent blood supply and healing potential compared to intra-articular ligaments.

However, there is significant controversy regarding the management of MCL tears in the setting of multi-ligament injuries. A systematic review found satisfactory results with both repair and reconstruction approaches in multi-ligament injuries, but noted a lack of high-quality comparative studies 3.

For combined ACL/MCL injuries, the traditional approach has been to treat the MCL conservatively first, followed by delayed ACL reconstruction after MCL healing and full range of motion is achieved (typically at 6 weeks). This approach helps reduce the risk of arthrofibrosis 4.

Important Considerations and Pitfalls

• Avoid prolonged immobilization: This can lead to stiffness, muscle atrophy, and delayed recovery
• Don't miss associated injuries: Carefully evaluate for concomitant meniscal, ACL, or PCL injuries
• Beware of residual instability: Incomplete MCL healing can increase the risk of failure if ACL reconstruction is performed
• Consider individual factors: Athletic demands, timing of injury, and tissue quality should influence treatment decisions

Return to Activity

• Light activities: 6-8 weeks
• Running: 10-12 weeks
• Return to sports: 12-16 weeks (depending on sport demands and functional testing)
• Full competitive return: When patient demonstrates full range of motion, adequate strength (>90% compared to uninjured side), and functional stability