sport injury

Question 1

mechanism of ACL

Answer 1

sudden deceleration, hyperextension and internal rotation of tibia on femur

Question 2

mechanism of PCL

Answer 2

sudden posterior displacement of tibia when knee is flexed or hyperextended (eg. dahsboard MVC injury)

Question 3

ACL and PCL history (similar and difference)

Answer 3

Similar:
- audible pop, immediate swell

ACL:
knee give way
inability to continue acitivity

PCL

• pain with push off
• cant descend stairs

Question 4

Physical exam of ACL vs. PCL

Answer 4

Similar:
- effusion (hemarthrosis)

ACL:
posterolateral jt line tenderness(bony tenderness)
\+ ant draw
\+ lachman (sensitive)
\+ pivot shift
* test for MCL, meinscal injuries

PCL:
anteromedial jt tenderness
\+ posterior draw
reverse pivot shift
check other ligament/ bone injuries

Question 5

treatment for ACL and PCL

Answer 5

ACL:
depends on if it is stable/ lifestyle
- stable -> immobilization 2-4 weeks with early ROM and strengthen
- high demand lifestyle -> ligament reconstruction

PCL:
- unstable knee/ young/ high demand lifestyle -> ligament reconstruction

Question 6

Collateral ligament tears:
- which side more common
- mechanism for each side
- clinical feature
treatment

Answer 6

1. medial > lateral
2. mechanism
   MCL: valgus force
   LCL: varus force
3. clinical features
   - effusion, tenderness above/ below jt line medially (MCL), laterally (LCL)
   - jt laxity with varus/ valgus force to knee
   (laxity with end point = partial tear; laxity with no end point = complete)
4. Treatment depends on tear
   - partial tear: immobilize 2-4 weeks with early ROM and strengthening
   - complete tear: immobilize at 30 degree flexion
   - multiple ligamentous injurys - sx

Question 7

what is o

donoghue’s unhappy triad

Answer 7

ACL rupture + MCL rupture + meniscus damage

Question 8

what are the tissue source for ACL?

Answer 8

autograft or allograft

• autograft includes hamstring/ bone patellar bone grade
• allograft is from donation from cadaver

Question 9

meniscal tears

• which side more common
• mechanism
• clinical features
• investigations
• treatment

Answer 9

1. medial more common than lateral
2. mechanism
   - twist force on knee when partially flexed (step down and turn)
3. feature
   - immediate pain, difficult weight bear, instability and clicking
   - increase pain with squat +/- twist
   - hemarthrosis with insidious onset (24-48 hour after injury)
   - jt line tender medial/ lateral
   - locking of knee (if meniscus mechanically obstruct extension)

investigation via MRI, arthroscopy

treat:
- not lock: ROM + strengthen (NSAIDs)
- lock/ or fail above tx” arthroscopic repair/ patial menisectomy

Question 10

anatomy of ACL and PCL

Answer 10

ACL
- from medial wall of lateral femoral condyle to anteromedial and posterolateral intercondyloid eminence of the tibial plateau

PCL
- lateral wall of medial femoral condyle to posterior intercondyloid eminence of the tibial plateau