MSK Session 9

Question 1

What lies posteriorly to the medial and lateral femoral condyles? Anteriorly?

Answer 1

Intercondylar fossa posteriorly

Shallow depression for patella articulation

Question 2

Where is the adductor tubercule and what muscle attaches here?

Answer 2

Medial epicondyle of femur

Adductor magnus

Question 3

What is the name for the superior tibial surface? Describe the shape of the medial and lateral surfaces and their separation?

Answer 3

Tibial plateau

Medial - concave
Lateral - convex

Separated by intercondylar eminence

Question 4

What do the menisci of the knee do? What shape are they and which one is stronger?

Answer 4

Deepen surface of articulation
Consist of tough fibrocartilage
Act as shock absorbers

Lateral is C-shaped so is stronger

Question 5

Describe the attachments of the menisci of the knee?

Answer 5

Attached to intercondylar areas
Attached to joint capsule via coronary ligaments
Anteriorly connected by transverse ligament of the knee

Question 6

What muscles stabalise the knee joint?

Answer 6

Quadriceps femoris

Inferior fibres of Vastus medialis and lateralis

+ iliotibial tract laterally

Question 7

What two groups of ligaments are extracapsular and intracapsular for the knee?

Answer 7

Extracapsular = collaterals

Intracapsular = cruciates

Question 8

What are the cruciate ligaments? How are they positioned?

Answer 8

Anterior and posterior cruciates

Anterior passes posteriorly and inserts laterally (from intercondylar surface of tibia to posterior part of medial side of lateral condyle of femur)

Posterior passes anteriorly and inserts medially (post intercondylar surface of tibia to anterior part of lateral surface of medial condyle of femur)

Question 9

What does the ACL do and describe its features?

Answer 9

Weaker of two
Relatively poor blood supply
Limits posterior movement of femur on tibia
Limits hyperextension

Question 10

What does the PCL do and describe its features?

Answer 10

Stronger of two
Limits anterior movement of femur on tibia
Limits hyperflexion
In weight bearing flexed knee - PCL is the main stabaliser

Question 11

What are the two extra-capsular ligaments and where do they originate and insert?

Answer 11

Medial (Tibial) collateral
Lateral (Fibular) collateral ligament - sits outside joint capsule

Extend from femoral epicondyles above to :

• medial condyle of tibia
• lateral surface of fibular head
  
  • reinforced by ilio-tibial tract

Question 12

What is clinically important about the medial collateral ligament?

Answer 12

Middle fibres attach directly to medial menisci.

Question 13

Name 1 anterior and 2 posterior ligaments that help to stabalise the knee?

Answer 13

Anterior = patellar

Posterior = oblique and arcuate popliteal ligaments

Question 14

What is the oblique popliteal ligament an extension of?

Answer 14

Semimembranous

Question 15

When the knee is flexed what muscles rotate the leg?

Answer 15

Medial - semitendinosus

Lateral - Biceps femoris

Question 16

What occurs when the knee is locked? How can this be unlocked?

Answer 16

Locked when femur rotates medially/internally over the tibia to allow medial condyle to bear weight

To unlock requires a posterior muscle - popliteus - to rotate femur externally

Question 17

What is the ‘unhappy triad’ in the knee?

Answer 17

Lateral blow to a flexed knee causing twisting.

Causes tears in MCL, medial menisci and ACL (as taught during flexion)

Question 18

What is the clinical test for testing the ACL and PCL?

Answer 18

Draw sign

for ACL push tibia anteriorly
for PCL push tibia posteriorly

Question 19

How can the PCL be damaged?

Answer 19

Falling onto tibial tuberosity with flexed knee

Causes tibia to be pushed backwards in relation to femur

Question 20

What are the three main bursa of the knee?

Answer 20

Suprapatellar
Prepatellar
Superficial infrapatellar

Question 21

If chronic friction e.g. excessive kneeling, or direct trauma is experienced on the knee, what can occur?

Answer 21

Bursitis

Prepatellar - Housemaids knee
Superficial infrapatellar - Clergymans knee

Question 22

If fluid accumulates in the synovial membrane of the knee what can occur?

Answer 22

Popliteal cyst - Baker’s cyst

In popliteal fossa
Sign of chronic knee effusion

Question 23

How can we investigate the knee?

Answer 23

Imaging - films/MRI

Arthroscopy

Aspiration

Clinical examination