Medial Collateral Ligament Tear Flashcards
What is the most commonly injured ligament of the knee?
MCL
Function of MCL
Valgus stabiliser of knee.
Mechanism of injury
Impact to the outside of the knee (direct blow in a valgus stress direction).
Non-contact MCL injuries can also occur, albeit less common from valgus stress with external rotation force like skiing.
MCL injuries can be graded from Grade I to Grade III.
Explain them.
Grade I - Mild injury with minimally torn fibres and no loss of MCL integrity.
Grade II - Moderate injury, incomplete tear and increased laxity of MCL.
Grade III - Severe injury, complete tear and gross laxity of MCL.
Clinial features
After trauma to lateral aspect of the knee.
Patient’s usually tell you they heard a ‘pop’ with immediate medial joint line pain.
Swelling usually happens after a few hours of injury.
If there is associated haemarthrosis the swelling will happen within minutes.
Examinations
Increased laxity when testing the MCL via valgus stress test.
Extreme tenderness along medial joint line
May be able to bear weight still
How can you distinguish grade II and grade III?
On medial stress testing.
Grade II is lax in 30 degrees of knee flexion but solid in full extension
Grade III is lax in both positions
Dx
Fractures
Meniscal injury
Multi-ligament tears like MCL&ACL
Investigations
Plain film radiograph to exclude any fracture.
Gold standard is MRI scan
This will show the exact extent and grade of tear.
Management depends on the grade of injury.
Grade I mx.
RICE + NSAIDs is the mainstay.
Strength training as tolerated.
Return to full exercise should be around 6 weeks.
Grade II mx.
Analgesia with a knee brace and weight bearing/strength training as tolerated.
Should be able to return to full exercise within 10 weeks.
Grade III mx.
Analgesia with a knee brace and crutches.
Any associated distal avulsion should warrant surgical consideration.
Should be able to return to full exercise within 12 weeks.
Complications
Instability in the joint
Damage to saphenous nerve
