Lecture 19: Anterior and Lateral leg

Question 1

What are the 4 borders of the anterior compartment

Answer 1

Anterior: skin and deep fascia

Medial: lateral surface of tibia

Lateral: anterior intermuscular septum

Posterior: interosseous membrane (IOM)

Question 2

Which of the leg bones is more medial and bigger

Answer 2

Tibia compared to fibula which is smaller and lateral

Question 3

What are the contents of the anterior compartment

Answer 3

4 muscles : Tibialis Ant, Extensor Digitorum Longus, Extensor Hallucis Longus and Peroneous Tertius.
1 nerve : Deep peroneal
1 artery: Anterior tibial

Question 4

Where does the patella tendon attach on the tibia

Answer 4

The tibial tuberosity

Question 5

What are bony bumps that stick out on the medial and lateral side of the ankle

Answer 5

The medial malleolus from the tibia and the lateral malleolus from the fibula

Question 6

What are the 7 bones of the ankle joint superior to inferior (medial to lateral 3 rows) : Taste c not c my intelligent lesbian

Answer 6

Talus 
Calcaneus
Navicular
Cuboid
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform

Question 7

What are the toe bones in the foot

Answer 7

Metarsals then Phalanges (proximal, middle and distal except for big toe which doesn’t have middle)

Question 8

What is dorsiflexion and plantarflexion and which joint does this revolve around involving which main bones

Answer 8

Dorsiflexion is flexing the ankle joint up and plantarflexion is extending the ankle joint down.
This joint is mainly between the tibia and the talus and some medial aspect of the fibula

Question 9

What is Inversion and Eversion and which joint does this revolve around involving which main bones

Answer 9

Inversion is rolling the foot to lift the medial border and Eversion is lifting the lateral border of the foot. This is at the Sub Talar and transverse tarsal joints

Question 10

What is the origin, insertion and action of Tibialis Anterior

Answer 10

O: is in the superior half of lateral tibia + IOM
I: Medial cuneiform and base of 1st metatarsal

Action: Dorsiflex the ankle and inverts the foot at subtalar joint

Question 11

What is the origin, insertion and action of Extensor Digitorum Longus

Answer 11

O: Lateral condyle of tibia + IOM and superior 3 quarters of medial fibula
I: Middle and distal phalanges of lateral 4 toes

Action: Extends the toes and dorsiflexes the ankle

Question 12

What is the origin, insertion and action of Extensor Hallucis Longus

Answer 12

O: Middle anterior fibula (under EDL) + IOM
I: Base of distal phalanx of great toe

Action: Extends Great toe and dorsiflexes the ankle

Question 13

What is the origin, insertion and action of Peroneus Tertius

Answer 13

O: Inferior 1/3 of fibula + IOM
I: Base of 5th metatarsal

Action: Dorsiflexes ankle and Everts foot at Subtalar joint

Question 14

What are the two extensor retinaculums used to prevent bowstringing of extensor tendons of the foot and their attachments.

Answer 14

Superficial Extensor retinaculum: passes tibia to fibula just superior to malleoli.

Inferior Extensor retinaculum: Y shaped with with one lateral attachment on upper surface of calcaneus and two medial attachments: medial malleolus and plantar aponeurosis.

Question 15

What are the contents of the lateral compartment of leg

Answer 15

2 muscles : Peroneus/ Fibularis Longus and Brevis
1 nerve: Superficial peroneal
No artery

Question 16

What is the origin, insertion and action of Peroneus Longus

Answer 16

O: Superior 2/3 of lateral fibula
I: Underneath the foot to go to the Medial cuneiform and Base of the 1st metatarsal (big toe)

Action: Evert the foot and weak plantarflexion

Question 17

What is the origin, insertion and action of Peroneus Brevis

Answer 17

O: Inferior 2/3 of lateral fibula
I: Base of 5th metatarsal

Action: Evert the foot and weak plantarflexion

Question 18

What are the two peroneal retinaculums used to prevent bowstringing of everter tendons of the foot and their attachments.

Answer 18

Superior peroneal retinaculum: attached above the lateral malleolus and below to the lateral surface of the calcaneus.

Inferior peroneal retinaculum: continuous with cruciate crural ligament and attached to the lateral surface of the calcaneous, with some on the peroneal trochlea to make a septum between the tendons

Question 19

What are the nerves that supply the anterior and medial compartments and trace the origin of this

Answer 19

Anterior comp.: Deep peroneal
Lateral comp: Superficial peroneal

These are the two branches from the common Peroneal/fibula nerve which had come around the neck of the fibula.

Common Peroneal nerve itself is one of two branches after the popliteal fossa (the other Tibial nerve which supplies posterior comp) from the Sciatic Nerve

The Sciatic nerve is through the Greater sciatic foramen and is from L4,5,S1-3 (Lumbar sacral plexus) .

Question 20

Describe the cutaneous innervation by the superficial and deep peroneal nerves

Answer 20

Superficial peroneal nerve continues as the cutaneous nerve after supplying the muscle, innervating the lateral half of anterior ankle and most of the dorsum of the foot.

The deep peroneal nerve travels with the anterior tibial artery, crosses the ankle joint, supplies the muscles of the foot and then becomes cutaneous in the first webspace between big toe and 2nd

Question 21

What nerve gives cutaneous for the medial and lateral half of the calf/ leg

Answer 21

Medial is saphenous nerve and lateral half is the common peroneal nerve then superficial branch

Question 22

What happens to the Femoral artery as after it becomes the popliteal artery as it enters the superior aspect of the popliteal fossa

Answer 22

It trifurcates into the Anterior tibial artery, Posterior tibial artery and the Peroneal artery

Question 23

Describe the path of the Anterior Tibial artery: what does it eventually become

Answer 23

It passes anteriorly through the gap in the IOM to become ant comp artery. Travels down to the ankle joint where it crosses midway between malleoli between tendons of EDL and EHL to become Dorsalis Pedis artery. There is a branch from this called Deep Plantar artery which goes between 1&2 Metatarsal to form part of the Deep Plantar arch

Question 24

Describe the path of the Posterior Tibial artery: what does it eventually become

Answer 24

This artery continues through deep posterior compartment followed by tibial nerve and veins, eventually being behind the medial malleolus where after it bifurcates into terminal branches : Medial and Lateral plantar arteries to the sole of the foot.

Question 25

Describe the path of the Peroneal artery what does it eventually become

Answer 25

It is the last branch, coming off Posterior artery after it passes deep to the tendinous arch of soleus. It runs laterally to the fibula whilst still in the posterior comp giving perforating branches to the muscles in the posterior and lateral comp and also nutrient to the fibula.

Question 26

What are the 2 Dorsal foot muscles and which toes are they focused on each

Answer 26

Extensor Digitorum Brevis= 4 lateral toes and Extensor Hallucis Brevis= great toe

Question 27

What Dorsal foot muscles origin, insertion, action and nerve supply

Answer 27

O: Calcaneous and Inferior Extensor retinaculum
I (EDB): Middle and distal phalanges of lateral 4 toes
I (EHB): Base of the proximal phalanx

Action: Extend its target toes at the MTPJ (As well as IPJ for EDB)

Nerve: Deep peroneal

Question 28

What is the cause and potential outcome of Compartment syndrome.

Answer 28

Cause is trauma making swelling/ fluid leakage which increases the pressure in the compartment to the point where the arterial supply is cut off and this puts muscles and nerves at risk of ischaemia and necrosis.

Question 29

What are clinical presentations of compartment syndrome and which leg compartment is it more likely to affect. what is treatment

Answer 29

Pain beyond expectation and with passive movement. Pallor, Pulselessness, Parethesia, paralysis. More likely in anterior compartment as 3 borders are quite inflexible so not much room for expansion. Treatment is fasciotomy to relieve the pressure