MSK - Soft Tissue Knee Injury

Question 1

Injury mechanism:

Valgus

Answer 1

MCL

Question 2

Injury mechanism:

Twisting

Answer 2

ACL or meniscal injury

Question 3

Injury mechanism:

Varus

Answer 3

LCL

Question 4

Injury mechanism:

Dashboard/hyperextension

Answer 4

PCL

Question 5

Injury mechanism:

Getting up from squatting

Answer 5

Meniscal tear

Question 6

What are the risk factors for an extensor mechanism rupture?

Answer 6

Previous tendonitis
Steroids
Chronic renal failure (ciprofloxacin)

Question 7

What is the main sign of an extensor mechanism rupture?

Answer 7

CAN’T STRAIGHT LEG RAISE

Question 8

How can an extensor mechanism rupture occur?

Answer 8

Falling onto flexed knee with quads contraction

Question 9

What is the function of Menisci?

Answer 9

Distribute load from convex femoral condyles to flat tibial articular surface

Question 10

What is the test of a Meniscal tear?

Answer 10

STEINMAN’s TEST

Question 11

How do you do Steinman’s Test?

Answer 11

Isolate tender point with hand + hold foot/heel in hand
Rotate AWAY from affected side
Degenerative tear = -ve
Acute tear = +ve

Question 12

What are the 4 types of meniscal tear?

Answer 12

Longitudinal
Bucket Handle
Radial
Parrot Beak

Question 13

What are the classic group sustaining meniscal tears?

Answer 13

Sporting injury in younger patients (or getting up from squat)

Older patients (>40yrs) can get atraumatic spontaneous degenerative tears

Question 14

True or False - 50% of ACL ruptures have meniscal tears

Answer 14

TRUE

Question 15

True or False - lateral meniscal tears are more common than Medial tears?

Answer 15

FALSE

Medial tears are 10x more common than lateral

Question 16

Why do radial tears (meniscal) have limited healing potential?

Answer 16

Only blood supply in peripheral 1/3rd

Question 17

When would you give Arthroscopic Menisectomy for a meniscal tear?

Answer 17

For mechanical symptoms
Painful catching or locking

Or irreparable tears or failed meniscal repair

Question 18

Buzzword - acute locked knee

Answer 18

Displaced bucket handle meniscal tear

Question 19

Test to check for a locked knee/bucket handle tear?

Answer 19

Heel Height (legs hang over edge of bed)

Question 20

What movement does MCL resist?

Answer 20

Valgus stress

Rupture = valgus instability

Question 21

What movement does LCL resist?

Answer 21

Varus stress

Uncommon rupture
Doesn’t heal - causes varus + rotatory instability)

Question 22

What is the treatment for MCL rupture?

Answer 22

Mx - brace, early motion, physio (pain settles after several months)

Heals well unless combined with ACL/PCL rupture

Question 23

True or False - peroneal nerve palsy has a high incidence with LCL rupture?

Answer 23

TRUE

Question 24

In what combo does LCL rupture tend to occur?

Answer 24

PCL/ACL

Question 25

What movement does ACL resist?

Answer 25

Resists anterior subluxation of tibia + internal rotation of tibia in extension (main stabiliser) Rupture = rotatory instability

Question 26

What is the reconstruction for an ACL rupture?

Answer 26

``` Reconstruction Autograft (hamstring, patella tendon) Allograft (achilles) ```

Question 27

What is the rule of thirds in regards to physio to stabilise ACL deficient knees?

Answer 27

1/3 compensate, function well 1/3 avoid instability by avoiding certain activities 1/3 don't compensate, frequent instability (can't go back to high impact sport)

Question 28

When would surgery be chosen in ACL rupture?

Answer 28

Rotatory instability NOT responding to physio Protect meniscal tear Rapid recovery for sport/job Adolescent or young DOES NOT treat pain or arthritis

Question 29

What is the test for an ACL rupture?

Answer 29

Lachmann's Test

Question 30

What are the risks of reconstruction in ACL rupture?

Answer 30

3/12 to 1yr rehab 10% failure rate Graft donor site morbidity Stiffness Most have radiographic signs of arthritis within 10 years

Question 31

What movement does PCl resist?

Answer 31

Posterior subluxation of tibia, i.e. anterior subluxation of femur + hyperextension of knee