Treatment of Medial Collateral Ligament (MCL) Injury
Most isolated MCL injuries, including complete grade III tears, should be treated non-surgically with early functional rehabilitation, as this approach results in good patient outcomes in the majority of cases. 1, 2, 3
Initial Management
- Control pain and swelling using the PRICE protocol (Protection, Rest, Ice, Compression, Elevation) immediately after injury 2
- Consider aspiration of painful, tense knee effusions for symptomatic relief 1, 2
- Use NSAIDs to improve healing and speed recovery 2
- Obtain radiographs if indicated by clinical examination to exclude fractures or bony avulsions 2
Treatment Algorithm Based on Injury Grade and Associated Injuries
Isolated MCL Injuries (No Concomitant Ligament Damage)
Grade I and II injuries:
- Non-surgical treatment is the standard of care with lightweight support and aggressive early functional rehabilitation 3, 4
- Functional rehabilitation with motion restoration and strengthening exercises is preferred over immobilization 2
- Manual joint mobilization combined with exercise therapy provides superior outcomes compared to exercise alone 2
Grade III (complete) tears:
- Non-surgical treatment remains the primary approach for isolated grade III MCL tears, with approximately 80% good outcomes expected 5, 3
- Surgical repair is indicated only in specific circumstances: 3
- Severe valgus malalignment present
- MCL entrapment over pes anserinus
- Intra-articular or bony avulsion
- Failure of conservative treatment after appropriate trial (typically 10+ weeks) 6
- Timing matters: Primary repair should be performed within 7-10 days of injury if surgery is indicated 3
Combined MCL and ACL Injuries
This is a critical clinical scenario where the MCL is treated differently:
- Non-surgical treatment of the MCL component results in good patient outcomes even when the ACL is surgically reconstructed 1, 2
- The ACL should be reconstructed surgically (preferably within 3 months to prevent additional meniscal and cartilage damage), while the MCL heals with conservative management 2
- Surgical treatment of the MCL may be considered only in select cases with severe instability 1, 2
Common Pitfalls and Caveats
Critical diagnostic error to avoid:
- There is an 80% incidence of concomitant ligament injury with grade III MCL tears 5
- Failure to identify associated ACL, PCL, or meniscal injuries significantly worsens prognosis and may lead to chronic instability 5
- Always perform comprehensive ligament examination including Lachman, anterior drawer, and posterior drawer tests
Specific subgroup requiring surgical attention:
- Proximal deep MCL tears at the femoral origin in high-level athletes may cause persistent symptoms despite conservative treatment 6
- Clinical features: persistent tenderness at proximal MCL attachment, pain with rapid external rotation, symptoms lasting >10 weeks 6
- These injuries typically require surgical repair and have good outcomes when recognized and treated appropriately 6
Chronic MCL insufficiency:
- Reconstruction is indicated when MCL injuries fail to heal or result in chronic medial instability 3
- Chronic injuries with valgus malalignment require a two-stage approach: distal femoral osteotomy first, followed by MCL reconstruction 3
- Augmentation repair techniques can be used when native ligament quality precludes primary repair 3
Bracing Considerations
- Prophylactic knee braces are not recommended for preventing MCL injuries, as evidence of effectiveness is limited and they may actually increase forces on the medial knee 1, 2
- Functional braces may be used for support during rehabilitation of mild to moderate MCL instability 1
- Lightweight support during early rehabilitation is reasonable for comfort 4