9/17 Anterolateral Leg

Question 1

Tibia and fibula orientation

Question 2

where is the lateral and anterior compartments located?

Answer 2

lateral compartment is on the fibula side

anterior compartment in front of the interosseous membrane

Question 3

osteology of the foot

Question 4

fibular trochlea

Question 5

Cuboid

• MOST LATERAL BONE IN DISTAL ROW OF TARSUS
• ARTICULATES WITH:

– POSTERIORLY= CALCANEUS

– ANTERIORLY= 4TH AND 5TH METATARSALS

– MEDIALLY= NAVICULAR AND LATERAL CUNEIFORM

• CUBOID SULCUS: – GROOVE (FIBULARIS LONGUS)

Question 6

Crural (Leg) Fascia

• Deep fascia of leg – Continuous with fascia lata
• Covers leg muscles
• Part of proximal attachment of underlying muscles
• Thickens distally to form extensor retinaculum (L., band or halter)
• Prevents bowstringing during dorsiflexion

Question 7

Crural Fascia does what?

Answer 7

encloses the 4 different compartments in the leg

Question 8

Crural Fascia

• Thick septa 1. anterior 2. lateral 3. posterior
• Structures in compartments share…

– Same general function – Nerve – Artery and vein

Answer 8

KNOW THIS !!!

Question 9

what function does the anterior compartment

Answer 9

Anterior (dorsiflexor/extensor) Compartment Muscles

Question 10

Anterior (dorsiflexor/extensor) Compartment Muscles

• Location:

– Anterior to interosseous membrane

• Muscles:

1. Tibialis anterior

2. Extensor hallucis longus

3. Extensor digitorum longus

4. Fibularis tertius (NOT SHOWN)

• Primary functions: – Dorsiflexion – Toe extension

Answer 10

Question 11

Tibialis Anterior

• Long thick muscle on anterolateral surface of tibia
• Proximal attachment: – Lateral tibial condyle and superolateral ½ of tibia
• Distal attachment: – Medial surface of first (medial) cuneiform and first metatarsal base
• Functions: – dorsiflexion and inversion of

Question 12

Extensor Digitorum Longus

• Proximal attachment: – Lateral tibial condyle – Anterior fibular surface – Interosseous membrane
• Distal attachment: – Each of the four tendons forms an extensor expansion over dorsum of lateral four proximal phalanges that divide into

– Two lateral slips (distal phalanx)

– One central slip (middle phalanx)

• Functions: – Extends lateral four digits – Dorsiflexion

Question 13

Fibularis Tertius

• Fuse with digitorum longus proximally
• Tendon does not attach to a digit
• Variably present
• Do not confuse with other “fibularis” muscles
• Attachments:

– Proximal: Anteroinferior fibular surface – Distal: Dorsum of fifth metatarsal base

• Functions: – Dorsiflexion – Eversion

Question 14

Extensor Hallucis Longus

• Lateral to tibialis anterior
• Proximal attachment:

– Anteromedial fibular surface and interosseous membrane. Medial to distal half of the proximal attachment of extensor digitorum longus

• Distal attachment: – Base of distal phalanx of hallux
• Functions: – Extend hallux – Dorsiflex ankle

Question 15

Anterior Compartment:

Deep Fibular Nerve

• One of two terminal branches of the common fibular nerve: – Begins between fibula and fibularis longus muscle. – Runs inferomedially with anterior tibial vessels between tibialis anterior and extensor hallucis longus. Ends in medial and lateral terminal branches on dorsum of foot.
• Supplies: – Anterior compartment muscles – Ankle joint and metacarpal phalangeal joints – Dorsal intrinsic foot muscles – Skin between first and second digits

Question 16

Anterior Compartment:

Anterior Tibial Artery

• Arises from popliteal artery
• Begins near inferior border of popliteus muscle – Tibial tuberosity demarcates approximate point of division of anterior and posterior tibial arteries.
• Passes anteriorly over interosseous membrane
• Descends on anterior surface of interosseus membrane between EHL and TA muscles with deep fibular nerve.
• Ends at ankle between malleoli to become dorsalis pedis artery.

Question 17

Lateral Compartment contains?

Answer 17

fibularis longus and brevis

superficial fibular nerve

Question 18

Fibularis Longus Muscle

• Extends from fibular head to sole of foot
• Superficual to fibularis brevis
• Attachments:

– Proximal: Head and superolateral 2/3 of fibula – Passes inferior just posterior to lateral malleolus – Runs obliquely and distally across sole of foot to attach distally to first metatarsal and medial cuneiform bone.

• Functions: – Eversion and plantar flexion

Answer 18

Question 19

cuboid sulcus is for?

Answer 19

groove for fibularis longus

Question 20

Fibularis Brevis Muscle

• Deep to fibularis longus
• Attachments:

– Proximal: Inferolateral 2/3 of tibia – Descends posterior to lateral malleolus

– Distal: dorsal surface of tuberosity on lateral side of fifth metatarsal

• Functions:

– Eversion – Plantarflexion

Answer 20

Question 21

Superficial Fibular Nerve

• One of the two terminal branches of the common fibular nerve.
• Begins between fibularis longus and fibula.
• Descends between fibular muscles and lateral to extensor digitorum longus
• Becomes superficial in distal third of leg to supply: – Anteroinferior leg – Nearly the entire dorsal surface of the foot – Most of the dorsal aspect of the digits

Question 22

Clinical Anatomy: Common Fibular Nerve

• Common fibular nerve winds superficially around fibular head – most commonly injured lower extremity nerve
• Injury results in paralysis of all anterior and lateral crural muscles
• Loss of dorsiflexion and eversion causes “foot-drop:” – Difficult to achieve heel strike – Patient has high stepping gait, waddling gait, or a swing-out gait – If leg swung strongly forward the foot strikes with a “clop” – Loss of sensation along anterolateral leg and dorsum of foot

Question 23

Lateral Compartment: Arterial Supply

• Branches that pass anteriorly from the fibular artery. The one compartment without a distinct arterial branch accompanying the compartment nerve.

– Fibular artery = largest branch of posterior tibial artery

Question 24

Clincial Anatomy: Crural Fascia

Leg compartmental syndromes

– Septa are very tough

– Trauma may lead to hemorage, edema, & inflammation

– Intracompartmental pressure may lead to ischemia and permanent injury

– Incising fascia (Fasciotomy) may be performed to relieve pressure.

Question 25

Shin Splints

• Due to repetitive microtrauma to tibialis anterior
• Inducing small tears to periosteum over tibia
• and/or tears to overlying deep fascia
• Is a mild form of compartmental syndrome (swelling of tibialis anterior due to repetitive ground reaction force).

Question 26

summary of all leg compartments