ACL

Question 1

Gene associated with ACL tears in females

Answer 1

COL5A1

Question 2

ACL tissue composition

Answer 2

90% type 1 collagen

10% type 3 collagen

Question 3

ACL tensile strength:

Answer 3

2200N anterior translation

Question 4

Segond fracture is:

Answer 4

bony avulsion of the anterolateral ligament in ACL tear

Question 5

ACL femoral tunnel placement should be:

Answer 5

on the lateral wall at 9/10 o’clock, and with 1-2mm of bone remaining between the tunnel and the lateral wall

Question 6

ACL tibial tunnel placement should be:

Answer 6

10mm anterior the PCL insertion, 75 degrees entry point from the horizontal on the anteomedial tibia

Question 7

Facts about BTB Allo:

Answer 7

30% rate of anterior knee pain
max load to fail = 2600N

complications:

• patella fracture or tendon rupture
• graft failure

Question 8

BTB graft failure associated with

Answer 8

• age <20 years

- <8mm diameter graft

Question 9

Facts about Quadruple Hamstring Auto:

Answer 9

• less painful
• high load to failure 4000N
• fixation strength may be less than BTB
• ?hamstring weakness in females leading to re-rupture

Question 10

“Windshield Wiper Effect”

Answer 10

suspensory fixation of hamstring graft causes tunnel abrasion due to movement during knee flexion/extension

Question 11

Allograft re-rupture rates?

Answer 11

4.3x higher than autograft for athletes <19 years

Question 12

For peds ACL recon, risk of physeal injury is increased with:

Answer 12

• LARGE TUNNELS >12mm
• oblique tunnels
• interference fixation
• high speed reaming
• dissection near the perichondrial ring of Lacroix

Question 13

Sagittal plane femoral tunnel malposition:

Answer 13

anterior graft causes knee tightness in flexion

- posterior graft causes knee to be tight in extension

Question 14

Sagittal plane tibial tunnel malposition

Answer 14

anterior graft causes knee tight in flexion and impingement with knee in extension

Question 15

Optimal graft-screw divergence should be:

Answer 15

< 30 degrees

Question 16

Biggest factor affecting return to sports after successul ACL reconstruction?

Answer 16

psychological and lifestyle factors

Question 17

early strengthening following ACL recon - advantages?

Answer 17

early eccentric strengthening at 3 weeks post-op

• higher quad strength and volume at 1 year wtihout increases in knee laxity
• immediate post-op wbat is safe
• immediate ROM 0-90 is safe

Question 18

Is there a difference in early vs delayed rehab protocols following ACL recon?

Answer 18

no, literature says no difference

-

Question 19

is bracing necessary following ACL recon?

Answer 19

not necessary

Question 20

Pathomechanics of ACL deficient knees

Answer 20

anterior translation
internal tibial rotation
medial tibial translation at 15-90 deg flexion (may cause OA)

Question 21

Classic bone bruise pattern in ACL injury predicts what?

Answer 21

prolonged range of motion deficit following reconstruction

Question 22

How much physeal disruption with ACL recon can cause growth disturbance?

Answer 22

7-9% of cross-sectional area

Question 23

Graft Strain During Rehab after ACL recon:

Answer 23

low strains with:

• isometric hamstring contractions at any knee flexion angle
• isometric quad contractions at knee flexion >60 deg (or combined quad and hamstring
• active knee ROM 35-90 deg

Question 24

secondary stabilizer to anterior tibial translation in ACL deficient knee?

Answer 24

posterior horn of medial meniscus