MCL Part I

MCL Part I

MCL is the main stabilizer of the medial aspect of the knee

Attachements:3 layers of the MCL: superficial middle and deep.  Each layer has its own insertion and origin, but generally speaking the MCL originates at medial femoral condyle and inserts on the medial margin of the meniscus and just below the medial tibial articular margin.

Static- MCL and posterior oblique ligaments are primary stabilizers of the knee in a static position

  -MCL provides 57% of resistance to valgus force at 5 degrees of flexion
  -MCL provides 78% resistance to valgus force at 25 degrees of flexion

Dynamic- Ligaments play a role in dynamic stabilization along with the semimembranosus the quadriceps and the pes anserine

 

MCL and ACL Relationship

-ACL tears are only 20% likey when there is no valgus laxity is seen upon clinical exam
  -ACL tears are 53% likely with valgus laxity at 30 degrees of flexion
  -ACL tears are 78% likely when the knee is in full extension and valgus laxity is present

 

MOI

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  -Valgus stress placed on knee when the foot is planted
  -Combined flexion/valgus/external rotation

Clinical Presentation

  -76% of patients with MCL tears can walk into an evaluation
  -Swelling and bruising between 2 and 24 hours
  -Tenderness to palpation with swelling focused on medial knee

Testing

 

Valgus in extension

  • +  test may indicate multiple ligament damage along with complete MCL

Valgus at 30 degrees

  • + test Rules in MCL deficiency/partial tear

 

Classification:

Grade I

  -Partial fiber tear
  -Localized tenderness but no instability

Grade II

  -Partial fiber tear
  -Increase tenderness and swelling

Grade III

  -Complete disruption with subsequent laxity
 - Grade III broken into three subcategories
 Grade 1+ -3-5 mm laxity
 Grade 2+ -6-10 mm laxity
 Grade 3+ - 10+ mm Laxity