Hip and Knee Ligaments

Question 1

Medial Meniscus

Answer 1

• C-shaped
• Attached to the MCL
• Posterior horn is attached to the semimembranosus via the capsule.

Question 2

Lateral Meniscus

Answer 2

• O shaped
• More mobile
• Does not attach to collateral or capsular ligaments
• Attaches to the arcuate ligament and popliteus muscle

Question 3

Menisci

Answer 3

• Menisci carry up to 70% of the load on the tibia.

- Knee joint stability during motion facilitated by menisci

Question 4

Primary Knee Ligaments

Answer 4

• ACL
• PCL
• MCL
• LCL:

**Restrictions listed above are for the tibia. It would be the opposite for the femur

Question 5

ACL Bundles

Answer 5

• 2 Bundles:
  Anteromedial (tighter in flexion)
  Posterolateral (tighter in extension)

Question 6

ACL

Answer 6

• Checks anterior tibial shear and ER
• Handles up to 75% of anterior tibial force at full extension
• Handles up to 90% of anterior tibial force at knee flexion

Question 7

PCL

Answer 7

• Checks posterior tibial shear

- PCL handles between 85 and 100% of posterior tibial force at both 30 and 90 degrees of flexion

Question 8

LCL

Answer 8

• Checks tibial adduction (varus force)/IR

- Handles approx 55% of varus force at full extension and increases with flexion

Question 9

MCL

Answer 9

• checks tibial abduction (valgus force)/ER

- Handles up to 50% of the valgus load on the knee

Question 10

Knee Hyperextension

Answer 10

• AKA genu recurvatum

- This position stresses out the posterior structures (like the joint capsule)

Question 11

Common Causes of Knee Hyperextension

Answer 11

• Inherent laxity of the knee ligaments
• Weakness of biceps femoris muscle
• Instability of the knee joint due to ligaments and joint capsule injuries
• Inappropriate alignment of the tibia and femur
• Congenital recurvatum

Question 12

Bursa of the Knee

Answer 12

• Functions to decrease friction between adjacent surfaces (i.e. b/t tendon–tendon or tendon–bone)
• 4 Anterior Bursae
• 3 Posterior Bursae
• 1 Medial Bursa

Question 13

Anterior Bursae

Answer 13

• Suprapatella
• Prepatellar
• Subcutaneous infrapatellar
• Deep infrapatellar

Question 14

Posterior Bursae

Answer 14

• Popliteus
• Semimembranosus
• Gastrocnemius

Question 15

Medial Bursa

Answer 15

Pes anserine (insertion of sartorius, gracilis, and semitendinosus)

Question 16

Other Knee Ligaments

Answer 16

• Oblique popliteal
• Arcuate popliteal
• Posterior meniscofemoral: ligament of Wrisberg
• Coronary ligament: also known as meniscotibial ligament. Blends with joint capsule but holds meniscus down to periphery of tibia
• Posterior ligament
• Transverse ligament: sometimes called the anterior meniscofemoral ligament. Helps prevent anterior horns of menisci from moving forward.
• Patellar ligament

Question 17

Ligaments of Hip

Answer 17

• Iliofemoral
• Pubofemoral
• Ischiofemoral

Question 18

Iliofemoral Ligamnt

Answer 18

Resists extension and IR, and is one of the strongest in the body

Question 19

Pubofemoral

Answer 19

Resists abduction and ER

Question 20

Ischiofemoral

Answer 20

Resists extension and IR

Question 21

Ligamentum Teres (or capitis) of the Hip

Answer 21

• Triangular in shape and somewhat flattened
• Made tense when the thigh is semiflexed, abducted or rotated outward
• Relaxed when limb is adducted
• Research suggests little influence as aligamentbut is important in transmitting arterial supply to the femoral head.