Soft Tissue Knee Injuries

Question 1

What is the purpose of the menisci?

Answer 1

to distribute load from convex femoral condyles to relatively flat tibial articular surfaces

Question 2

What are the differences between the lateral and medial menisci?

Answer 2

medial is fixed whislt the lateral meniscus is more mobile; medial is under a greater amount of shear pressure

Question 3

Why does the knee pivot on the medial meniscus through flexion and extension?

Answer 3

due to shpae and soft tissues the tibia interally rotates on flexion and externally rotates on extension

Question 4

What type of stress does the MCL resist?

Answer 4

valgus stress

Question 5

what type of stress does the LCL resist?

Answer 5

varus stress

Question 6

What does the ACL resist?

Answer 6

anterior subluxation of the tibia and internal rotation of the tibia in extension

Question 7

What does the PCL resist?

Answer 7

posterior subluxation of the tibia and hyperextension of the knee

Question 8

Why does the MCL heal well?

Answer 8

has a very good blood supply

Question 9

What type of instability does an MACL rupture lead to?

Answer 9

valgus instability

Question 10

What type of instability does an ACL rupture lead to?

Answer 10

rotatory instability

Question 11

What type of instability does a PCL rupture lead to?

Answer 11

recurrent hyperextension or instability descending stairs

Question 12

What causes a meniscal tear in younger patients?

Answer 12

a sporting injury or getting up from squatting positions

Question 13

What can cause a medinscal tear in older patients?

Answer 13

atraumatic spontaneous degenrate tears

Question 14

How are meniscal tears investigated?

Answer 14

MRI

Question 15

Which meniscus is more likely to be torn?

Answer 15

medial 10x as common

Question 16

Why is there limited healing potential with meniscal tears?

Answer 16

only the peripheral third has a blood supply

Question 17

When should a menisectomy be considered?

Answer 17

mechanical symptoms- painful catching or locking or irreparable tear os failed meniscal repair

Question 18

How should the menisci appear on MRI?

Answer 18

like a black boe-tie; any white in the bows indicates a tear

Question 19

What does an acute locked knee signify?

Answer 19

a significant displaed bucket handle meniscal tear

Question 20

What would happen if the knee remains locked for an extended period of time

Answer 20

Patient may develop fixed flexion defomrity

Question 21

What is the link between a degenerative meniscal tear and OA?

Answer 21

probably represents the first stage of OA

Question 22

What are hte grades in a knee ligament injury?

Answer 22

grade 1- sprain-tear some fibres but macroscopic structure intact; grade 2- partial tear; grade 3- complete tear

Question 23

What are the treatments for an MCL injury?

Answer 23

brace; early motion; physi

Question 24

How are ACL treated?

Answer 24

repair doesnt work- reconstruction only- autograft using patellar tendon or hamstrings;PT

Question 25

What is the rule of thirds in ACL rupture

Answer 25

a third can compensate and are able to funcion well; a third can avoid instability by avoiding certain activites and a third do not compensate and have frequent instability

Question 26

What is the role of ACL reconstruction?

Answer 26

to fix rotary instaibilty not responding to physio- does not treat pain or prevent arthritis

Question 27

How is the LCL injured?

Answer 27

by varus and hyperextension

Question 28

What nerve is commonly damaged in an LCL tinjury?

Answer 28

the common fibular nerve

Question 29

What is the problem with an LCL injury?

Answer 29

it doesnt heal

Question 30

What causes a PCL rupture?

Answer 30

a direct blow to anterior tibia or hyperextension injury

Question 31

What are the symptoms of PCL ruptre?

Answer 31

popliteal knee pain and bruising

Question 32

What type of instability results with PCL rupture?

Answer 32

recurrent hyperextension or feeling unstable when going downstairs

Question 33

What are the common complications associated with knee disloactions?

Answer 33

popliteal artery injury (tear; intima tear and thrombosis); nerve injury- common fibular nerve; compartment syndrom

Question 34

What is the managment fro a knee dislaction?

Answer 34

emergency reduction and recheck of neurovascular status; multi-ligament reconstruction

Question 35

What causes a patellar dislocation?

Answer 35

rapid turn or direct blow

Question 36

Who gets patellar dislocation?

Answer 36

females; adolescents; ligamentous laxity; valgus knee

Question 37

How many patients with patellar disolcation get recurrent dislocation?

Answer 37

10%

Question 38

What type of trauma causes an extensor mechanism rupture?

Answer 38

a fall onto flexed knee with quads contraction

Question 39

What predisposes to an extensor mechanism rupture?

Answer 39

previous tendonitis; steroids; chronic renal failure; ciprofloxacin

Question 40

What is seen on exam with an extensor mechanism rupture?

Answer 40

unable to straight leg raise; palpable gap

Question 41

What is the treatment for an extensor mechanism rupture?

Answer 41

surgical repair

Question 42

Haemarthrosis is seen with what injuries?

Answer 42

ACL rupture or fracture

Question 43

What causes pain on the joint line?

Answer 43

meniscal/chondral pain

Question 44

What is the most likely cause of this presentation? twist, pop, haemarthosis; generalised pain; pain settles after a few days; rotary instability

Answer 44

ACL rupture

Question 45

what is the most likely cause of this presentation?- getting up from squatting, sudden sharp pain medial joint line, effusion, recurrent medial pain and catching +/- locking

Answer 45

meniscal tear