Anterior/Lateral Leg

Question 1

tibial plateau

Answer 1

@superior surface tibia

has medial and lateral condyles
-intercondylar eminence b/t (projections fit into intercondylar fossa of femur)
-minisci + ACL + PCL will attach

Question 2

fibula

Answer 2

basically just a mucle attachment site, not weight wearing

Question 3

interosseous membrane

function

Answer 3

1. stabilizes tib and fib
2. physical barrier b/t ant/post but gaps at top and bottom for vessels and nerves travel b/t compartments
3. muscles attach

separates ant/post compartment

Question 4

superficial fascia

Answer 4

aka subQ tissue w/ veins + cutaneous N + lymph vessels/nodes + fat

main superficial veins= great saphenous V (medial) + smaller/lesser saphenous (post)

Question 5

deep fascia

Answer 5

aka crural fascia
-cont w/ fascia lata/popliteal fascia/deep fascia foot

> 3 intermuscular septa + retinacula (ankle)

Question 6

retinacula

Answer 6

bands of CT that overlie tendons and hold in place

retain tendons

Question 7

leg compartments

general

Answer 7

1. anterior
2. lateral
3. posterior (super and deep)

thigh has ant/med/post

Question 8

anterior compartment

Answer 8

ankle dorsiflexors + toe extensors

motor by deep fibular N
blood by anterior tibial A

Question 9

lateral compartment

Answer 9

foot evertors (main) + plantarflexion (weak)

motor by superficial fibular N
blood by perforating branches (no major A)

Question 10

posterior compartment

Answer 10

superficial = ankle plantarflexion
deep = toe flexor

motor by tibial N

Question 11

anterior compartment muscles

Answer 11

1. tibialis anterior
2. extensor hallucis longus (EHL)
3. extensor digitorum longus (EDL)
4. fibularis tertius

Question 12

foot drop

Answer 12

injury to deep fibular N = can’t dorsiflex so toes not clear the ground when walking

can also occur w/ injury to common fib N or tibialis anterior muscle

Question 13

tibialis anterior

Answer 13

main ankle dorsiflexor and foot invertor

most ant and superficial muscle

og @lateral tibia + anterior surface of IM
in @medial cuneiform + base of MT1 (medial)

IM = interosseous membrane

Question 14

shin splints

Answer 14

overuse of tibialis anterior aka repeated microtrauma = small tears in periosteum lateral to tibia

swelling/edema of periosteum (bc hard to drain fluid) + pain in middle half of leg

common in runners bc constant dorsiflexion

Question 15

extensor hallucis longus

EHL

Answer 15

main extensor of hallux + assist dorsiflex ankle

deepest muscle in anterior compartment

og @ant surface fibula + ant IM
in @ distal phalanx of hallux

hallux is big toe/MT1

Question 16

extensor digitorum longus

EDL

Answer 16

main extensor of digits II-V + assist ankle dorsiflexion

og @ lateral condyl tibia + ant fibula + IM
in @ middle + distal phalanges of II-V

Question 17

fibularis tertius

Answer 17

assist dorsiflex ankle + assist lateral compartment everting foot

og @ distal end fibula + IM
in @ base of MT5

longus and brevis are in lateral compartment

IM = interosseous membrane

Question 18

anterior compartment syndrome

Answer 18

bleeding/swelling = inc pressure so no room for extra fluid
-deep fibular N gets compressed = weaken dorsiflexion and pain down leg
-dec blood flow = ischemia

from trauma or injury, treat w/ fasciotomy

Question 19

lateral compartment muscles

Answer 19

1. fibularis longus
2. fibularis brevis

Question 20

fibularis brevis

Answer 20

deep to longus

og @ distal 2/3 lateral fibula
-tendon hooks behind lateral malleolus like a pulley to redirect force

in @ base of MT5

Question 21

fibularis longus

Answer 21

superficial to brevis

og @ head + prox 2/3 lateral fibula
-tendon also hooks behind lateral malleolus

in @ medial cuneiform + base of MT1
-wraps around cuboid bone anteromedially

Question 22

combined fibularis actions

Answer 22

retinacula changes direction of pulling forces to ensure insertion is puled to origin

lateral margin of foot raises/medial margin drops (eversion) OR
heel pull up/front half drops (plantarflex)

Question 23

eversion mechanism

Answer 23

brevis pulls lateral side up
longus pulls medial side down

Question 24

innervation

Answer 24

sciatic > common fibular N > split @under neck of fibula =
deep fibular (ant comp, post div L4-S1) + superficial fibular N (lat comp, post div L5-S2)

Question 25

cutaneous innervation

Answer 25

1. saphenous N from femoral=medial leg
2. lateral sural cutaneous N= prox 2/3 lateral
3. superficial fibular N= distal 1/3 anterolat leg + dorsum foot

Question 26

common fibular N injury

Answer 26

very superficial as crosses head/neck fibula

if damage proximal to split = affects all distal/downstream branches aka all ant muscles + all lat muscles + skin ant/lat/most dorsum

weak dorsiflex, eversion, extend toes

Question 27

arterial supply

Answer 27

popliteal A split into posterior/anterior tibial A

anterior tibial A contributes to genicular anastomosis

anterior tibial + fibular + posterior tibular contribute to anastomosis around ankle

Question 28

superficial veins

Answer 28

-great saphenous V drain to femoral V
-small/lesser saphenous drain to popliteal V

perforating veins penetrate crural fascia so allow superficial to drain into deep veins

Question 29

deep veins

Answer 29

in accompanying veins/venae comitantes form aka not just a singular tube (two smaller instead)

Question 30

lymphatics

Answer 30

ant lymph vessels travel medial/superior to inguinal region
>drain to superficial inguinal nodes>deep inguinal nodes

some parts lateral travel post/super to popliteal fossa
>drain to superificial popliteal nodes > deep inguinal nodes