MCL Stress test

Question 1

What does the MCL stress test diagnose?

Answer 1

MCL laxity or complete rupture

Question 2

What is the rationale behind the MCL stress test?

Answer 2

By applying a valgus force, you gap the medial joint line and put the MCL under tension. Having the knee in full extension and slight flexion can be used to differentiate the degree of damage.

Question 3

MCL Stress test procedure

Answer 3

1) Explain & IC
2) Patient in long sitting with relaxed quads and hamstrings
3) Physio takes the weight of one leg, holding with one hand on the thigh and the other on the medial aspect of the calf/ankle.
4) Physio applies a distraction force to the medial aspect of the knee joint, attempting to create gapping.
5) Perform the test on both legs in full extension & at 20-30 degrees of flexion
6) Observe gapping and end feel and compare one side to the other.

Question 4

What is a positive result of the MCL Stress test?

Answer 4

At 20: pain @ joint line & no laxity = MCL mild injury
At 20: pain @ joint line & some laxity = moderate injury, ligament’s integrity is compromised but it is still partially intact.
At 20: pain & gross instability (visual gapping) = complete rupture of the medial collateral ligament.
At full extension: any instability in this position = MCL tear and cruciate ligament involvement as the knee should be stable in 0 even with a complete rupture of the medial collateral ligament

Question 5

What is a negative result of the MCL Stress test?

Answer 5

No pain or laxity evident at full extension or 20-30 flexion, findings
equivocal as the non-affected knee.

Question 6

Result: At 20: pain @ joint line & no laxity
What does this mean?

Answer 6

Mild MCL injury

Question 7

Result: At 20: pain @ joint line & some laxity
What does this mean?

Answer 7

moderate injury, ligament’s integrity is compromised but it is still partially intact.

Question 8

Result: At 20: pain & gross instability (visual gapping)
What does this mean?

Answer 8

complete rupture of the medial collateral ligament

Question 9

Result: At full extension, any instability in this position
What does this mean?

Answer 9

MCL tear and cruciate ligament involvement as the knee should be stable in extension even with a complete rupture of the medial collateral ligament