Week 5: Knee Joint & Ligaments

Question 1

What is the classification of the knee joint, and what movements are available?

Answer 1

• Condylar – movement in two planes
• Flexion/extension and internal/external rotation (of flexed knee)

Question 2

What are the components of the knee joint?

Answer 2

• Femoral condyles (medial & lateral) - convex
• Tibial condyles (medial & lateral) - convex
• Patella (patello-femoral joint)

Question 3

What is the tibiofemoral joint?

Answer 3

Complex synovial condylar joint

Question 4

What is the patellofemoral joint?

Answer 4

Synovial joint and is part of the knee joint complex

Question 5

Where does the joint capsule of the knee attach?

Answer 5

Attaches around joint margins – but anteriorly is replaced by patellar ligament

Question 6

Which plateau of the proximal tibia is bigger?

Answer 6

Medial - 50% bigger to accomodate bigger femoral condyle

Question 7

What is the relationship of the fibrous capsule with the collateral ligaments?

Answer 7

• Medially – blends with medial collateral ligament
• Laterally – it is separate from the lateral collateral ligament

Question 8

What is the patellar ligament?

Answer 8

Terminal part of the tendinous insertion of the quadriceps femoris muscle to the tibial tuberosity

Question 9

Describe the attachment sites of the patellar ligament:

Answer 9

Strong flat band attached to the inferior border of the patella and is continuous over the front of the patella with the fibers of the quadriceps tendon to attach distally to the tibial tuberosity

Question 10

What are the functions of the patella ligament?

Answer 10

• Attaches the quadriceps muscle group to the tibia
• Resists upwards displacement of the patella

Question 11

Describe the location of the infrapatellar (Hoffa’s) fat pad:

Answer 11

• Fills the space between the patellar ligament and the anterior intercondylar area of the tibia
• Attachments to the patella tendon (proximally), patella (inferior pole) and anterior horns of the meniscus

Question 12

What is the function of the infrapatellar fat pad?

Answer 12

It acts a deformable space filler- (can change shape, position, pressure and volume thought with movements of the knee joint

Question 13

Is the infrapatellar fat pad an intra- or extra-capsular structure?

Answer 13

Intracapsular, but extrasynovial, its posterior surface is covered with synovial lining

Question 14

What tissue are plicae made of?

Answer 14

Synovium (inward fold of the synovial membrane)

Question 15

What structures does the infrapatellar plica attach to?

Answer 15

Deep surface of the infrapatellar fat pad, extending to the intracondylar notch

Question 16

Discuss the role of the infrapatellar plica structures in producing knee pain:

Answer 16

• May be impinged or stretched within the knee joint - irritation of these structures gives rise to what is known as ‘Plica Syndrome’ –particularly the medial plica

Question 17

The iliotibial band is comprised of the longitudinally directed fibres from which muscles?

Answer 17

Gluteus maximus and tensor fascia lata

Question 18

Within what soft tissue structure is the iliotibial band found?

Answer 18

Fascia lata

Question 19

Describe the attachments of the iliotibial band:

Answer 19

• It is a thickened portion of the fascia lata
• Attaches to the iliac crest and to the linea aspera via the lateral intermuscular septum
• Attaches to the lateral tibial condyle

Question 20

Can the iliotibial band be stretched at the knee joint?

Answer 20

No. Due to its thickness, and attachment along the length of the femur, the iliotibial band
- The proximal portion of the iliotibial band may be stretched over the lateral aspect of the hip joint

Question 21

What two muscles take attachment from the distal ½ of the lateral intermuscular septum?

Answer 21

Short head biceps femoris and vastus lateralis

Question 22

What is the oblique popliteal ligament?

Answer 22

Fibrous expansion of the tendon of the semimembranosus muscle, provides posterior reinforcement to the capsule

Question 23

What movement is the oblique popliteal ligament most likely to restrict?

Answer 23

Hyperextension

Question 24

What structure does the tendon of popliteus pass under to insert on the lateral femoral condyle?

Answer 24

Lateral collateral ligament

Question 25

Describe the location of the arcuate (popliteal) ligament:

Answer 25

Back of the head of the fibula, arches upward and medially over the tendon of the popliteus muscle to spread out over the posterior surface of the capsule

Question 26

Describe the attachment sites of the longer superficial medial collateral ligament:

Answer 26

* Medial epicondyle of femur to medial epicondyle of tibia and medial surface of tibial shaft

Question 27

Does the medial collateral ligament blend with the knee joint capsule?

Answer 27

Yes

Question 28

To what intra-articular structure do the deep fibres of the medial collateral ligament attach?

Answer 28

The outer periphery of the medial meniscus

Question 29

Describe the attachment sites of the lateral collateral ligament:

Answer 29

Lateral condyle of femur to fibula head

Question 30

Does the lateral collateral ligament blend with the knee joint capsule?

Answer 30

No, it is extracapsular - The lateral collateral ligament is separated from the capsule by a fat pad, through which run some of the vessels and a nerve to the knee joint (the inferior lateral genicular nerve and vessels)

Question 31

What tendon passes deep to the lateral collateral ligament?

Answer 31

Tendon of popliteus (intracapsular)

Question 32

What is the function of the collateral ligaments?

Answer 32

* MCL opposes valgus forces * LCL opposes varus forces

Question 33

How could the integrity of the MCL be tested?

Answer 33

Place the knee in extension and apply an abduction force to the tibia - a positive test will result in gapping of the medial aspect of the knee joint and/or reproduction of pain

Question 34

What type of ligaments are the cruciate ligaments?

Answer 34

Intra-capsular, but as they are wrapped in synovial membrane are described as being extra synovial

Question 35

What are the attachments of the anterior cruciate ligament?

Answer 35

Tibia intercondylar eminence to the posterior lateral femoral condyle

Question 36

From the tibia to the femur, describe the direction of fibre bundles of the ACL:

Answer 36

Anteromedial and posterolateral - Run posteriorly and superiorly

Question 37

What are the attachment sites of the posterior cruciate ligament?

Answer 37

Posterior intercondylar eminence of the tibia to the medial condyle of the femur

Question 38

From the tibia to the femur, describe the direction of fibre bundles of the PCL:

Answer 38

Anterolateral and posteromedial - Run superiorly and anteriorly

Question 39

Describe the function of the cruciate ligaments:

Answer 39

* ACL prevents anterior displacement of the tibia and internal rotation of the tibia on the femur * PCL prevents posterior displacement of the tibia on the femur