ACL

Question 1

Functions of ACL

Answer 1

limits anterior translation of the tibia on the femur
contributes to rotational stability

Question 2

Highest prevalence in sports for ACL injuries

Answer 2

basketball
soccer
alpine skiing
lacrosse
football

Question 3

Mechanism of injury for ACL

Answer 3

MOI
70% are non-contact injuries
tibia translates anteriorly while knee is in slight flexion and valgus

Question 4

Patient Reports with ACL injury

Answer 4

pop or tearing sensation
pain
immediate swelling = hemarthrosis
sense of instability
lack of full knee extension at midstance

Question 5

Clinical Exam of ACL injury

Answer 5

joint effusion
decreased active and passive ROM
decreased force production quads
decreased extension at midstance
partial weight bearing or limp

Question 6

Diagnosis of acl injury

Answer 6

feeling of soft end feel when it should be firm

MRI is the gold standard
manual gold standards = lachman (78%) and pivot shift (89%)

Question 7

Associated injuries with ACL injury

Answer 7

meniscal tears
multi-ligament tears
osteochondral defects
bone marrow edema
tendon tears
arterial tears
nerve injury
dislocation

Question 8

ACL Reconstruction

Answer 8

Autografts
Allografts

Question 9

Autografts

Answer 9

own tissue
patellar tendon (central 1/3)
hamstring

Question 10

Allografts

Answer 10

cadaver grafts
taken from achilles, posterior tib, anterior tib

Question 11

Single Bundle ACL

Answer 11

gold standard, has the best results

Question 12

Femoral tunnel placement

Answer 12

frontal plane malpositioning

Question 13

Anterior tunnel misplacement

Answer 13

knee is tight in flexion and loose in extension

Question 14

Posterior misplacement

Answer 14

knee is lax in flexion and tight in extension

Question 15

Psychosocial Complications of ACL

Answer 15

surgery/rehab
loss of sports season
loss of scholarship funding
lowered academic performance
kinesiophobia
disability

Question 16

Long-Term Complications of ACL

Answer 16

Post-traumatic osteoarthritis following ACL injury is 87%

Possible causes:
inflammatory cytokine
osteochondral defects
osteochondral lesions
loss of meniscus cartilage
persistent instability

Question 17

ACL strain is greatest between

Answer 17

10° to 30° of knee flexion

Question 18

ACL strain gradually decreases between

Answer 18

30° to 60° of knee flexion

Question 19

ACL strain is insignificant at

Answer 19

knee flexion angles greater than 60°

Question 20

Day 1 intervention for ACL

Answer 20

get swelling under control, restore extension
check ankle dorsiflexion and begin stretching gastrocsoleus complex. practice hip hinging

Question 21

Quads Contraction

Answer 21

loading the ACL
anteriorly directed force on the proximal tibia, most notably at 0° to 60° flexion

Question 22

Hamstring contraction

Answer 22

unloading the ACL
posteriorly directed force on the proximal end of the tibia

Question 23

Squatting with heels off the ground

Answer 23

over 3 times more ACL loading compared to squatting with heels on the ground

at greater knee flexion angles, heels lift off, knees go beyond toes, shear force on ACL increases

Question 24

Minimize load on ACL

Answer 24

lean trunk forward 30 to 40° from vertical during squats at knee angles 15-90° using hip flexion (vs lumbar flexion)

leaning trunk forward helps you to optimally recruit hamstrings

Question 25

Single vs double leg squats

Answer 25

significantly greater ACL load during single leg squat knee moves forward an average of 10 cm beyond the toes compared to double leg squats

Question 26

Sagittal plane motion of trunk can influence the moments at hip and knee

Answer 26

landing with trunk forward increases the moment at the hip while decreasing moment at knee landing with trunk erect increases the moment at knee while decreasing moment at hip