Lower leg and Ankle Anatomy

Question 1

tibia

Answer 1

primary weight bearing bone

Question 2

4 compartments lower leg

Answer 2

anterior (most common place for compartment syndrome): dorsiflexors and toe extensors
TA, EHL, EDL, fibularis tertius, anterior tibial artery → dorsalis pedis artery in foot, deep fibular n.

lateral: plantar flexors and evertors
fibularis longus, fibularis brevis, superficial fibular n.

superficial: plantar flexors
gastroc, soleus, plantaris

deep: invertors and toe flexors
TP, FDL, FHL, posterior tibial a., tibial n.
all of these pass through the tarsal tunnel to enter the plantar surface of the foot.

Question 3

ankle ligaments

Answer 3

ATFL: most commonly injured, prevents anterior translation talus/foot; anterior drawer test
CFL: 2nd most commonly injured in lateral ankle sprain, fibularis longus/brevis tendons run over it
PTFL: almost never torn
deltoid: medial ankle stabilizer, triangular ligament
tibiofibular syndesmosis: interosseous ligament

Question 4

ankle plantarflexion (musc, inn)

Answer 4

gastrocnemius: S1-2 tibial n.
soleus: S1-2, tibial n.

plantaris

tibilaris posterior: L5-S1, tibial n.

FDL, FLD, fib long, fib brev also contribute (toe flexors), mainly evertors

Question 5

ankle dorsiflexion (musc, inn)

Answer 5

tibialis anterior: L4-5, deep fibular n.

fibularis tertius: L5-S1, deep fibular n.

EHL, EDL also contribute; main action is to extend toes

Question 6

ankle inversion (musc, inn)

Answer 6

tibialis posterior: L5-S1, tibial n.

tibialis anterior: L4-5, deep fibular n.

Question 7

ankle eversion (musc, inn)

Answer 7

fibularis longus and brevis: L5-S1, superficial fibular n. (main evertors)

fibularis tertius: L5-S1, deep fibular n.

Question 8

ankle pronation and supination (movements involved)

Answer 8

pronation: eversion, dorsiflexion, external rotation of tibia
supination: inversion, plantar flexion, internal rotation of tibia

Question 9

Maisonneuve fracture

Answer 9

high ankle sprain complication - proximal fibular fracture (rupture of tibiofibular syndesmosis)

syndesmosis splits → extends up → proximal fibular fracture

order XR to r/o fracture

Question 10

shin splints

Answer 10

medial tibial stress syndrome, medial shin pain

excessive overload over time (running) → microtears of muscle-periosteum interface (traction periositis)

Tx: correct pronation

Question 11

tibial stress fracture

Answer 11

d/t untreated shin splints

actual microfracture of tibia d/t overuse

reimage to follow fracture healing

Question 12

talus fracture

Answer 12

fracture of bone that articulates w tibia, usually d/t forced dorsiflexion w axial load

talar body fracture (AKA dome) have greater risk of AVN

Tx: NWB if non displaced, ORIF otherwise

Question 13

calcaneus fracture

Answer 13

MC foot fracture d/t traumatic axial load

Tx: cast and NWB if stress fx or small fx; otherwise ORIF

Question 14

most common foot fracture

Answer 14

calcaneus fracture

Question 15

Sever’s disease

Answer 15

posterior heel pain in children d/t excessive overuse of gastroc (achilles tendon) pulling on calcaneus → calcaneal aopohysitis

Question 16

posterior heel pain in athletic child

Answer 16

sever’s disease

overuse injury w achilles pulling on calcaneus → calcaneal apophysitis

Question 17

syndesmosis injury

Answer 17

high ankle sprain, injury of tibiofibular syndesmosis (interosseous membrane) d/t excessive external rotation forces; common football injury

talus pushes into fibular → separation, tearing ligaments

sometimes causes Maisonneuve fracture

squeeze test positive

Tx: NWB CAM boot 3 wks

Question 18

lateral ankle sprain

Answer 18

injury to ATFL/CFL/PTFL d/t excessive inversion forces
rolling ankle inward
most common type and mechanism of ankle sprain

grading 1-3; ATFL/CFL tears

beware fibularis longus/brevis tendon injury

anterior drawer (ATFL) and talar tilt (CFL) positive

Question 19

most common ankle sprain

Answer 19

lateral ankle sprain (ATFL/CFL/PTFL)

order of torn ligaments is usually ATFL→CFL→PTFL

Question 20

grading of lateral ankle sprains

Answer 20

1: partially torn ATFL, intact CFL
2: fully torn ATFL, partially torn CFL
3: fully torn ATFL, fully torn CFL

Question 21

lateral ankle sprain, common co injury

Answer 21

beware fibularis longus/brevis tendon injury

Question 22

medial ankle sprain

Answer 22

deltoid ligament (very sturdy) injury d/t excessive eversion

not common bc deltoid ligament strong

deltoid ligament: anterior and posterior tibiotalar ligaments, tibionavicular ligament, tibiocalcaneal ligament

Question 23

deltoid ligament structures

Answer 23

very strong ligament, eversion injury uncommon

components: anterior and posterior tibiotalar ligaments, tibionavicular ligament, tibiocalcaneal ligament

Question 24

tarsal tunnel syndrome

Answer 24

pain/numbness/tingling d/t compression of structures underneath the flexor retinaculum

region behind median malleolus, invovling structures that pass underneath the flexor retinaculum (tarsal tunnel)

tibial n/a/v, TP, FDL, FHL

Question 25

tarsal tunnel acronym

Answer 25

Tom Dick and Very Nervous Harry

tibial n/a/v, TP, FDL, FHL

Question 26

ankle bursitis

Answer 26

Haglund deformitiy AKA “pump bump”

excessive friction forces (high heels)

bursae: retrocalcaneal, retroachilles

Question 27

Haglund deformity

Answer 27

AKA “pump bump”

ankle bursitis d/t friction forces, usually high heels

Question 28

ACS of leg

Answer 28

emergency fasciotomy indicated

usually anterior compartment

trauma → venous damage → blood pumps in but can’t pump out → ischemia/necrosis

extreme out of normal proportion pain stretching muscles of that compartment

w/u: manometry (compartment pressure testing)

Question 29

chronic exertional compartment syndrome

Answer 29

chronic condition, temporarily raised intracompartmental pressure during exercise

pain/paresthesias/weakness worse or increased intensity w exercise

Dx: manometry

Tx: fasciotomy

Question 30

TA tendon injury

Answer 30

overuse (tenosynovitis) or rupture (eccentric overload) → TA tendon (dorsiflexor/invertor) injury

foot slap may be audible/visible

pain w resisted dorsiflexion or passive plantarflexion w tendon palpation

Question 31

tibialis posterior tendon injury

Answer 31

overuse; TP is plantar flexor and invertor

higher risk w gait abnormalities, excessive pronation, medial ankle sprains (deltoid ligament sprain, rare)

remember TP wraps around medial malleolus

too many toes sign

Question 32

FHL injury

Answer 32

dancer’s tendonitis

actions w lots of big toe flexion against resistance (dancing) → FHL (long big toe flexor) injury

Question 33

fibularis tendon injury

Answer 33

often d/t overuse eversion activity (overpronation, sports) or as result of bad lateral ankle sprain

pain w resisted plantar flexion and eversion, or passive dorsiflexion and inversion

Question 34

achilles tendon injury

Answer 34

pain posterior heel over achilles tendon and calcaneus d/t repetitive eccentric overload → inflammation and degeneration

risk of tendonosis (degredation d/t improper healing)

distal 2-6 cm of achilles tendon is poorly vascularized → predisposed to tears