[16] Medial Collateral Ligament Tear Flashcards
What is the most commonly injured ligament of the knee?
The medial collateral ligament
What is the primary function of the MCL?
It acts as a valgus stabiliser of the knee
How is the MCL most commonly injured?
When external rotational forces are applied to the lateral knee, such as a football tackle impacting the outside of the knee
How can MCL injuries be graded?
From 1-3
What is a grade I MCL injury?
Mild injury, with minimally torn fibres and no loss of MCL integrity
What is a grade II MCL injury?
Moderate injury, with an incomplete tear and increased laxity of the MCL
What is a grade III MCL injury?
Severe injury, with a complete tear and gross laxity of the MCL
How does a MCL tear present?
The patient may report hearing a ‘pop’ with immediate medial joint line pain. Swelling tends to follow after a few hours
When does swelling follow a torn MCL within minutes?
If there is associated haemarthrosis
What will be found on examination with a torn MCL?
- Increased laxity when testing the MCL
- Extreme tenderness along the medial joint line, but may be able to weight bear
How is the MCL tested?
The valgus stress test
How can a grade II and III tear be distinguished clinically?
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
What are the main differentials to consider in a suspected MCL tear?
- Fracture
- Haemarthrosis
What investigations should be done in suspected MCL tear?
- Plain film radiograph
- MRI scanning
What is the purpose of x-rays in suspected MCL tear?
Exclude any fracture
