29. Ligament injuries of the knee – injury mechanism, diagnosis and treatment

Question 1

What is valgus?

Answer 1

Medial displacement of the knee joint

Question 2

What is varus?

Answer 2

Lateral displacement of the knee joint

Question 3

What ligament provides resistance against valgus forces?

Answer 3

Medial collateral ligament

Question 4

What ligament provides resistance against varus forces?

Answer 4

Lateral collateral ligament

Question 5

How can you test for MCL injury?

Answer 5

Valgus stress testing: The knee flexed 25-30° and then is abducted. Pain and excessive laxity indicate stretching or tearing of the MCL

Question 6

How can you test for ACL injury?

Answer 6

Anterior drawer test

Lachman test:
* the examiner should place one hand behind the tibia and the other on the patient’s thigh. It is important that the examiner’s thumb be on the
tibial tuberosity.
* On pulling anteriorly on the tibia, an intact ACL should prevent forward translational movement of the tibia on the femur (“firm endpoint”).

Question 7

What imaging can be used to diagnose tendon injuries?

Answer 7

MRI

Question 8

What is the treatment for tendon injury?

Answer 8

• Physical therapy
• Surgical Intervention: Treatment plan based on the patient’s pre-injury level of activity and on motivational factors.
  If the ligament has been pulled from its attachment on the bone, the ligament is reattached to the bone with either large sutures or special clips.

Reconstruction tightening up the loose ligament or replacing the loose ligament with a tendon graft (autogenous hamstring tendons).