Knee ligament injuries

Question 1

What does the ACL do?

Answer 1

stabilise the knee joint by being the primary restraint to limit anterior translation of the tibia and contribute to rotational stability

Question 2

When does an ACL tear usually occur?

Answer 2

When there is history of twisting the knee while weight bearing, from landing from a jump

Question 3

How will an ACL tear usually present?

Answer 3

Rapid joint swelling and significant pain, instability

Question 4

What specific tests are done for an ACL tear?

Answer 4

Lachmans test and anterior draw test

Question 5

What is Lachmans test?

Answer 5

putting the knee at 30 degrees of flexion and stabilise the femur, pull the tibia forward to assess the amount of anterior movement of the tibia compared to the femur

Question 6

What is the anterior drawer test?

Answer 6

flexing the knee to 90 degrees and placing the thumbs in the joint line and index finder on the hamstring tendons posteriorly, force is then applied anteriorly to demonstrate tibial excursions

Question 7

What are the differential diagnosis for ACL tear?

Answer 7

Fracture, meniscal tear, collateral tear, quadriceps or patellar ligament tear

Question 8

What investigations would need to be done for an ACL tear?

Answer 8

radiograph of the knee to exclude bony injuries and see if lipohaemarthrosis is present, MRI scan for diagnosis

Question 9

What is the initial management for an ACL tear?

Answer 9

Rest, Ice, Compression, Elevation

Question 10

What is the conservative management for an ACL tear?

Answer 10

rehabilitation, strength training of the quadriceps to stabilise the knee, canvas knee splint

Question 11

What is the surgical treatment for an ACL tear?

Answer 11

tendon or an artificial graft with prehabilitiation before hand

Question 12

What are the complications of ACL tear?

Answer 12

post traumatic osteoarthritis

Question 13

What is a PCL tear and how would i present?

Answer 13

high energy trauma to proximal tibia, immediate posterior knee pain, instability and positive posterior draw test

Question 14

What is the medial collateral ligaments function?

Answer 14

to act as a values stabiliser of the knee

Question 15

When does the MCL usually tear?

Answer 15

external rotational forms are applied to the lateral knee such as a impact to the outside of the knee

Question 16

What is a grade I MCL tear?

Answer 16

mild injury, minimally torn fibres and no loss of MCL integrity

Question 17

What is a grade II MCL tear?

Answer 17

moderate injury with an incomplete tear and increased laxity of the MCL

Question 18

What is a grade III MCL tear?

Answer 18

severe injury, with complete tear and gross laxity of the MCL

Question 19

What are the clinical features of a MCL tear?

Answer 19

trauma to lateral aspect of the knee, immediate medial joint line pain, swelling, increased laxity when testing the MCL via the values stress test, tender along joint line, may be able to weight bear

Question 20

How can grade II and III MCL tear be distinguished on medial stress testing?

Answer 20

Grade II is lax in 30 degrees of knee flexion but solid in full extension, grade III is lax in both

Question 21

what are the differential diagnosis for MCL tear?

Answer 21

fractures, meniscal injury and collateral ligament tears

Question 22

What is the gold standard for MCL tear scanning?

Answer 22

MRI

Question 23

What is the management for a grade I MCL tear?

Answer 23

RICE, analgesia, strength training, full exercise in 6 weeks

Question 24

What is the management of grade II MCL tear?

Answer 24

Analgesia with a knee brace and weight bearing/strength training, full exercise in 10 weeks

Question 25

What is the management for grade III MCL tear?

Answer 25

analgesia with knee brace and crutches, 12 weeks full exercise

Question 26

What are the complications of an MCL tear?

Answer 26

instability of the joint, damage to the saphenous nerve

Question 27

What is a meniscal tear?

Answer 27

the c shaped fibrocartilage found in the knee joint tears

Question 28

What is the function of the meniscus in the knee?

Answer 28

shock absorbers and increase articulating surface area

Question 29

What is the medial meniscus attached to?

Answer 29

MCL, the lateral is not attached to the LCL

Question 30

What is the most common cause of meniscal tear?

Answer 30

trauma related injury (twisted knee while flexed and weight bearing) and degenerative disease

Question 31

What are the types of meniscal tears?

Answer 31

Vertical, longitudinal, transverse, degenerative

Question 32

What are the clinical features of meniscal tears?

Answer 32

tearing sensation, intense sudden onset pain, swelling, locked in flexion and unable to extend if the meniscal tear causes a free body

Question 33

What happens on examination of the meniscal tears?

Answer 33

tinderness in the joint line, joint effusion, limited knee flexion, McMurrarys test and Apleys grind test

Question 34

What are the differential diagnosis of meniscal teats?

Answer 34

fracture, cruciate ligament tear, collateral ligament tear, osteochondritis dissecans

Question 35

What imaging would you do for meniscal tears?

Answer 35

Plain radiograph to exclude fracture and then MRI

Question 36

What is the management for meniscal tears?

Answer 36

rest and elevation, compression and ice, atroscopic surgery if the teat is in the outer third of the meniscus can be sutured together or if the inner third can be trimmed

Question 37

What are the complications of meniscal tears?

Answer 37

osteoarthritis, knee arthroscopy can cause DVT, damage to local structures, saphenous nerve and vein, peroneal nerve and popliteal vessels