Associated Injuries

If besides the valgus force there is also external tibial torsion it is probable an injury to the anterior cruciate ligament (ACL)

Medial meniscal tears are rare in isolated MCL injuries and when happen, they usually are peripheral tears due to stretching of the deep MCL









Classification

The injuries of the MCL are classified according to its severity based on the physical examination findings

Grade I (partial rupture): medial opening of 0 - 5 mm

Grade II (partial rupture): medial opening of 5 - 10mm

Grade III (complete rupture): medial opening of more than 10mm








Diagnosis

• History: previous knee injuries, mechanism of injury, symptoms
  
  
• Clinical Examination
  
  
  

Swelling is common, if hemarthrosis is present always think in a possible ACL or meniscal tear.



Palpate the femoral origin, the midsubstance and the tibial insertion of the MCL looking for tender spots and palpable defects.




Valgus Stress Test in extension and 30° of flexion

• The valgus stress test is the most reliable test to evaluate the MCL
  
  
• Always examine the normal side first and compare, do not expect a 3cm opening, an opening of 5 to 8 mm is indicative of an MCL injury
  
  
• A positive valgus stress test at 30° of flexion is indicative of an isolated injury of the MCL but if it is positive in extension there is also an injury to the posterior oblique ligament and perhaps the ACL.
  
  
  
  

Always rule out ACL injuries performing the Lachman
&
The drop leg Lachman tests


The Lachman test is the most reliable test to evaluate the ACL.





The Drop Leg Lachman Test can be helpful in the acute setting and in 'big guys'. Remember, the isolated injury to the MCL does not justify a positive Lachman test



Meniscal test can be difficult to perform especially in the acute situation