Clinical Anatomy Considerations of the Lower Limbs

Question 1

What confers passive stability to the hip joint?

Answer 1

Bony architecture = femoral head and acetabulum, ball and socket
Acetabulum labrum = fibrocartilaginous rim along the margin of the acetabulum
Ligaments and muscles

Question 2

How does a posterior hip dislocation typically occur?

Answer 2

During a traumatic event when the hip in a flexed, adducted and medially rotated position

Question 3

What nerve can be affected by a posterior hip dislocation?

Answer 3

Sciatic nerve (L4-S3 anterior rami), most commonly the common fibular division

Question 4

Where does the sciatic nerve run?

Answer 4

Leaves pelvis through greater sciatic foramen inferior to the piriformis, runs posterior to the acetabulum at the level of the ischium

Question 5

What is Trendelenburg’s sign?

Answer 5

Inferior movement of the contralateral hip when standing on one leg, due to dysfunctional hip abduction caused by muscle weakness or paralysis

Question 6

What muscles abduct the hip?

Answer 6

Gluteus medius = originates between the anterior and posterior gluteal lines of the ilium
Gluteus minimus = originates between the anterior and inferior gluteal lines of the ilium

Question 7

Where do the gluteus medius and minimus insert onto?

Answer 7

The greater trochanter of the femur

Question 8

Where does the superior gluteal nerve (L4-S1) run?

Answer 8

Leaves pelvic cavity via the greater sciatic foramen superior to the piriformis, passes between gluteus minimus and gluteus medius

Question 9

What are some features of femoral shaft fractures?

Answer 9

Displaced by muscular contraction, causing rotation and/or shortening, sharp fragments may injure nearby structures

Question 10

What is a maisonneure fracture?

Answer 10

Separating of the distal tibia and fibular can cause tearing of the tibiofibular syndemosis (e.g fracture to proximal fibular)

Question 11

What are potential neural complications of a maisonneure fracture?

Answer 11

Anterior compartment = deep fibular nerve, dorsiflexion
Lateral compartment = superficial fibular nerve, eversion
Cutaneous innervation = superficial fibular nerve and deep fibular nerve

Question 12

What causes foot drop?

Answer 12

Dysfunction of anterior compartment musculature

Question 13

What are some features of foot drop?

Answer 13

May lead to changes in gait, high steppage and foot slap

Question 14

What do active components of joint do?

Answer 14

Add to the movement of the joint (e.g muscle)

Question 15

What does the labrum of the acetabulum do?

Answer 15

Stops bony edges grinding against the joint and keeps head of the femur in the joint

Question 16

Why are ligaments at a joint in a spiral?

Answer 16

So they can contract when the joint moves to add to the stability

Question 17

What is the classic position of the head of the femur in a hip dislocation?

Answer 17

Superior, lateral and posterior to the acetabulum

Question 18

What can damage to the common fibular nerve cause?

Answer 18

Loss of movement in the foot

Question 19

Do distal or middle femur features affect the blood supply more?

Answer 19

Distal = femoral artery runs anteriorly on femur before moving posteriorly

Question 20

What are the menisci of the knee?

Answer 20

Wedge shaped cartilage = absorb shock and make joint more stable

Question 21

What is varus posture?

Answer 21

Knees oppose each other, compression on medial side

Question 22

What is valgus posture?

Answer 22

Knees touch each other, compression on lateral side

Question 23

What happens if you spread the tibia and the fibular at the bottom?

Answer 23

They will break apart at the top

Question 24

Lack of what action causes foot drop?

Answer 24

Inability to dorsiflex