Common Knee conditions - Acute

Question 1

ACL rupture

Answer 1

Proprioceptive organ –> when ruptured, altered neuromuscular control at knee

MOI: Back: forward flexed, rotated opposite side; hips: ADD, IR; knee: less flexed, valgus; tibial rotation: IR or ER; landing pattern: one foot out of control unbalanced

S&S: Sudden onset; rapid moderate to severe swelling; feeling of instability; pain

CT: Swelling
Lachman’s +
Anterior drawer +
Lever’s sign +

Can have MCL and medial meniscus test + (due to MOI and attachment)

Question 2

PCL rupture

Answer 2

Far less common than ACL

MOI: Direct blow to the tibia in a posterior direction

S&S: Mild to moderate effusion and pain
(No pop/snap –> may not realise they have ruptured their PCL)

CT: Post sag sign +
Post drawer +

Question 3

MCL tear

Answer 3

MOI: Rapid valgus motions usually with flexed knee (consider MOI of ACL)
Typically injured while cutting/landing/jumping

S&S: Sudden onset; rapid moderate to severe swelling; feeling of instability; pain

CT: Valgus stress +
Palpat° medial joint line
Feeling of instability

Also check ACL test

Question 4

LCL tear

Answer 4

Not as common as MCL injury, but the same grading scale

MOI: Direct trauma/force to the medial knee joint forcing the knee into varus

S&S: pain over lateral knee joint

CT: Varus stress +

Question 5

Meniscal tears

Answer 5

Often injured with ACL ruptures due to attachment to MDC and medial capsule

MOI: Twisting/pivoting motions, usually combined movement of knee flexed, compression, and femoral rotation

S&S: Possible tearing sensat° at time of injury; Pain and swelling incr. >24h; swelling come and go; intermittent locking, joint line tenderness

CT: Pain during turning, change of direct°, jumping
Clicking +/-
McMurray’s +
Thessaly’s +
Knee ROM decr.
Pain joint line palpat°