Anterior and Lateral Leg

Question 1

Calcaneus

Answer 1

Largest tarsal bone
Most posterior
Contains the fibular trochlea: ridge on lateral surface

Question 2

Cuboid

Answer 2

Most lateral bone in distal row of tarsals
Articulates with
Posteriorly: calcaneus
Anteriorly: 4th and 5th metatarsals
Medially: navicular and lateral cuneiform
Cuboid sulcus: groove for fibular is longus

Question 3

Crural (Leg) Fascia

Answer 3

Deep fascia of leg, continuous with fascia lata
Covers leg muscles
Part of proximal attachment of underlying muscles
Thickens dismally to form extensor retinaculum which prevents bowstringing during dorsiflexion

Question 4

3 septa in leg

Answer 4

Anterior
Lateral
Posterior
Structures in compartments share same general function, N, A and V.

Question 5

Anterior compartment muscles

Answer 5

Dorsiflexor/extensor
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Fibularis tertius

Question 6

Tibialis anterior

Answer 6

Anterolateral surface of tibia
O: lateral tibial condyle and superolateral 1/2 of tibia
I: medial surface of 1st cuneiform (medial) and first metatarsal base
N: Deep fibular N.
A: dorsiflexion and inversion of foot

Question 7

Extensor Digitorum Longus

Answer 7

O: lateral tibial condyle
Anterior fibular surface
Interosseous membrane
I: extensor expansion over dorsal of lateral four proximal phalanges that divide into 2 lateral slips (dorsal phalanx) and 1 central slip (middle phalanx)
N: Deep fibular N.
A: extends lateral four digits, dorsiflexion

Question 8

Fibularis Tertius

Answer 8

Fuse it’s digitorum longus proximallly
Tendon does not attach to a digit
Variably present
O: anterioinferior fibular surface
I: dorsum of 5th metatarsal base
N: Deep fibular N.
A: dorsiflexion, eversion 
Tendon runs anterior to lateral malleolus

Question 9

Extensor Hallucis Longus

Answer 9

Lateral to tibialis anterior
O: anteriomedial fibular surface and interosseous membrane
I: base of distal phalanx of hallux 
N: Deep fibular N.
A: extend hallux, dorsiflexion ankle

Question 10

Deep Fibular N.

Answer 10

One of the two terminal branches of the common fibular N.
Begins between fibula and fibularis longus M.
Runs inferomedially with anterior tibial vessels and extensor hallucis longus
Ends in medial and lateral terminal branches on dorsum of foot
Supplies anterior compartment Ms., ankle joint and metatarsal phalangeal joints, dorsal intrinsic foot Ms., skin between first and second digits (cutaneous branches)

Question 11

Anterior Tibial Artery

Answer 11

Arises from popliteal A.
Begins near inferior border of popliteus M.
Passes anteriorly over interosseous membrane
Division of anterior and posterior tibial arteries at tibial tuberosity
Descends between EHL and TA Ms. with deep fibular N.
Ends at ankle between malleoli to become dorsalis pedis A.

Question 12

Lateral Compartment

Answer 12

Between anterior and posterior crural septa
Fibularis brevis M.
Superficial fibular N.
Fibularis Longus M.
No artery is in this compartment

Question 13

Another name for fibularis/fibular

Answer 13

Peroneus/perineal

Question 14

Fibularis Longus M.

Answer 14

Extend from fibular head to sole of foot
Superficial to fibularis brevis
O: head and superolateral 2/3 of fibula
Passes inferior just posterior to lateral malleolus and runs obliquely and dismally across sole of foot
I: first metatarsal and medial cuneiform bone
A: eversion and plantar flexion

Question 15

Fibularis Brevis M.

Answer 15

Deep to fibularis longus M.
O: inferolateral 2/3 of tibia
Descends posterior to lateral malleolus
I: dorsal surface of tuberosity on lateral side of 5th metatarsal 
A: Eversion and plantarflexion

Question 16

Superficial Fibular N.

Answer 16

One of two terminal branches of the common fibular N.
Begins between fibularis longus and fibula
Descends between fibular Ms. and lateral to extensor digitorum longus
Becomes superficial in distal 1/3 of leg
Anterioinferior leg
Nearly the entire dorsal surface of the foot
Most of the dorsal aspect of the digits

Question 17

Foot-drop

Answer 17

Common fibular N. Is injured
Most commonly injured lower extremity nerve
Paralysis of all anterior and lateral crural Ms.
Unable to dorsiflexion and some eversion
Difficult to achieve heel strike
High stepping gait, waddling gate, or swing-out gate
Foot strikes with clop
Loss of sensation along anterolateral leg and dorsum of foot

Question 18

Arterial supply of lateral compartment

Answer 18

Branches that pass anteriorly from the fibular artery

Question 19

Fibular Artery

Answer 19

Largest branch of posterior tibial artery

Question 20

Leg compartmental syndromes

Answer 20

Septa are very tough
Trauma may lead to hemorrhage, edema, and inflammation
Intracompartmental pressure may lead to ischemia and permanent injury
Fasciotomy-incising fascia; may be performed to relieve pressure

Question 21

Shin Splints

Answer 21

Due to repetitive microtrauma to tibialis anterior
Inducing small tears to periosteum over tibia and/or tears to overlying deep fascia
Mild form of compartmental syndrome (swelling of tibialis anterior)