Living Anatomy of the Lower Limb

Question 1

At what vertebral level is the Posterior Superior Iliac Spine (PSIS)?

Answer 1

S2

Question 2

What structures of note are at S2?

Answer 2

the middle of the sacro-iliac joints
the bifurcation of the iliac arteries
End of the spinal cord, beginning of the filum terminale

Question 3

At what vertebral level is the suprcristal plane?

Answer 3

between L4 and L5

Question 4

For what clinical procedure is the supracristal plane useful?

Answer 4

Epidural

Question 5

What are the boundaries of the femoral triangle?

Answer 5

Superior: Inguinal ligament
Lateral border: medial border of sartorius
Medial border: lateral border of adductor magnus
floor: pectineus, iliopsoas etc
roof: fascia lata

Question 6

What are the contents of the femoral triangle?

Answer 6

From lateral to medial:
Femoral Nerve (N)
Femoral Artery (A)
Femoral Vein (V)
Empty Space (E)
Lymphatics (L)

Question 7

What are the boundaries of the popliteal fossa?

Answer 7

Superomedial: semitendinosus and semimebranosus
Superolater: biceps femoris
Inferomedial and lateral: respectice heads of gastrocnemius

Question 8

What are the contents of the popliteal fossa?

Answer 8

From lateral to medial:
Tibial Nerve (N)
Popliteal Vein (V)
Popliteal Artery (A)

+ termination of small saphenous vein
+origin of common fibular nerve from tibial nerve

Question 9

Describe the course of the common fibular nerve

Answer 9

leaves the popliteal fossa and courses around the head of the fibula
at this point it is palpable, but also vulnerable to injury

Question 10

What are the 4 pulse points in the lower limb commonly used in clinical examination?

Answer 10

Femoral Pulse
Popliteal Pulse
Posterior Tibial Pulse
Dorsalis Pedis Pulse

Question 11

What procedures may be carried out on the femoral artery in the femoral triangle?

Answer 11

Coronary angiography
stenting
Arterial Blood gas (ABG)

Question 12

What is the clinical use of these pulse points?

Answer 12

Assess the condition of the blood supply to the lower limb

identify the level of any possible obstruction

Question 13

Describe the superficial venous drainage of the lower limb

Answer 13

2 main veins:
Great Saphenous vein: - past medial malleolus, up medial side of leg, posterior to medial condyle of femur
- formed by union of dorsal venous arch and vein of big toe

Small Saphenous vein: - ascends posterior to lateral malleolus, ascends between heads of gastrocnemius and into popliteal vein
- formed from union of dorsal venous arch and vein of little toe

Question 14

How do varicose veins arise?

Answer 14

Great saphenous vein prone to becoming varicose
dilates in such a manner that valves do not close
incompetent veins so blood pools

Question 15

Name the locations of the L3 and L5 dermatomes?

Answer 15

L3 = Knee

L5 = Big Toe

Question 16

How would you test for the L3 and L4 myotomes?

Answer 16

L2,3 = Hip flexion

L4,5 = Hip extension

Question 17

How would you test the S1 and S2 myotomes?

Answer 17

S1,2 = Ankle Plantarflexion

Question 18

What movement would you expect with a knee reflex?

What vertebral levels are being tested?

Answer 18

Extension of the leg at the knee joint

L3,4