Lecture 9 - Leg Flashcards
Bones of the leg
Tibia
Fibula
(Femur)
Tibia
Most common long bone to be broken
Relatively poor blood supply
Anteromedial surface is bare
Soleal line on posterior surface
Fibula
Lateral malleolus important in ankle stability
Site for muscle attachment
Tibia Structures- Proximal
Anterior:
- medial and lateral condyles
- tuberosity
- tubercles of intercondylar eminence
Posterior:
- medial and lateral condyles
- tubercles of intercondylar eminence
- articulate facet for fibula
- soleal line
Tibia Structures- Distal
Anterior:
-medial malleolus
Posterior:
- fibular notch
- soleal line
Fibular Structures- Proximal
Head
Apex
Articulate Surface for lateral condyle of tibia
Fibular Structures- Distal
Lateral malleolus (with articulate facet for talus)
Does the tibia or the fibula contain an interosseous border?
BOTH
- face each other when two bones articulate
- site of attachment of interosseous membrane
Crucial Fascia
Continues with fascia latae
Fascia forms retinacula in foot
Fascia Latae
Attachment to anterior and medial borders of tibia
Continuous with periosteum
Leaves bare area
Superior (extensor) retinaculum
- proximal to malleoli
- binds tendons in anterior crural compartment
Inferior (extensor) retinaculum
Y shaped
Flexor retinaculum
Binds tendons of the deep posterior compartment
Superior/Inferior perineal retinacula
Bind tendons of lateral crural compartment
Cutaneous Nerves of Sup. Post. Compartment
Lateral sural cutaneous nerve
Medial sural cutaneous
Sural nerve runs with lesser saphenous vein
Muscles of Sup. Post. Compartment
Gastrocnemius, plantaris, soleous, triceps surae, common insertion
Gastrocnemius
- Crosses both knee and ankle joint
- Two heads form inferior boundaries of the popliteal fossa
- Lateral head may have a sesamoid bone: •Fabella
Plantaris
•May be absent •Tendon may be used for hand surgery
Soleus
•Broad multipennate muscle •Unijoint muscle
Triceps surae
Soleus + two heads of gastrocnemius
common insertion
Calcaneus via tendocalcaneus (Achilles tendon)
Tibial Nerve
- Supplies all muscles in posterior compartment
- Divides into medial and lateral plantar nerves inferior and posterior to medial malleolus
- Gives off medial sural cutaneous nerve
- Joins with communicating branch of common peroneal (fibular) nerve to form:
- Sural nerve: •Cutaneous
Posterior tibial artery
•Largest branch of popliteal artery
Provides both Superficial and Deep Comp
•Divides into medial and lateral plantar arteries deep to origin of abductor hallucis muscle
Peroneal (fibular) artery
- Most important branch of posterior tibial artery
- Supplies lateral compartment and popliteus muscles
- Supplies other muscles in posterior compartment
Muscles of the Deep Posterior Compartment
Popliteus, flexor digitorum longus, flexor hallicus longus, tibialis posterior
Popliteus
•Lies in floor of popliteal fossa •Flexes and rotates knee
Flexor digitorum longus
- Tendon passes posterior to medial malleolus and to tendon of tibialis posterior
- Plantarflexes foot at ankle joint
Flexor hallucis longus
- Tendon occupies groove on posterior surface of talus:
- Continuous with groove on plantar surface of sustentaculum tali.
- Tendon passes posterior to medial malleolus.
- Tendon passes between two sesamoid bones.
- Push-off muscle for walking, jumping, running
Tibialis posterior
- Functions in plantar flexion and foot inversion
* Helps to maintain medal longitudinal arch
Tibialis nerve
supplies deep post. compartment
Muscles of the anterior compartment
Tibialis anterior, extensor digitorum longus, peroneus (filbularis) terius, extensor hallicus longus
Tibialis Anterior
- Lateral to crest of tibia
- Foot dorsiflexion and inversion
- L4-L5
- Paralysis results in foot drop
Extensor digitorum longus
- Four tendons of insertion:
- Each tendon inserts on an extensor expansion similar to arrangement in hand.
- Toe extension at MTP and also dorsiflexion
Peroneus (fibularis) tertius
- Part of extensor digitorum longus
- Sometimes missing
- Foot dorsiflexion an eversion
Anterior compartment functions
toe extension
ankle dorsiflexion
deep peroneal (fibular) nerve
Innervation of anterior compartment
•L4-5 to tibialis anterior.
•L5-S1 for remaining muscles.
•Runs deep to extensor digitorum longus.
•Accompanies anterior tibial artery between extensor hallucis longus and tibialis anterior muscles.
Anterior tibial artery
Blood Supply to anterior compartment
•Smaller terminal branch of popliteal artery
•Begins at inferior border of popliteus muscle
•Becomes dorsalis pedis artery at ankle joint
Muscles of the Lateral Compartment
Peroneus (fibularis) longus, Peroneus (fibularis) brevis
Peroneus (fibularis) longus:
- More superficial of the two
- Easily palpated
- Its tendon uses lateral malleolus as a pulley
- Tendon crosses sole of foot and inserts on first metatarsus and cuneiform
- Helps to maintain transverse and longitudinal arches of the foot
Peroneus (fibularis) brevis
- Deep to peroneus longus
- Inserts on lateral tuberosity
- Functions in plantar flexion and foot eversion
Superficial peroneal (fibular) nerve:
•Deep to peroneus longus •Inserts on lateral tuberosit
Blood supply of Lateral Compartment:
- No major arteries in lateral compartment
* Muscular branches arise from the peroneal artery: •Branch of posterior tibial
Spinal cord levels of lat compartment
L5, S1-S2
