MOB TCD Anterior and Lateral and Posterior Compartments

MOB TCD Anterior and Lateral and Posterior Compartments of Calf Professor Emeritus Moira O’Brien FRCPI, FFSEM (UK), FTCD Trinity College Dublin

MOB TCD Cutaneous Supply of Calf • Saphenous first branch is infrapatellar branch it • Supplies medial side of the calf and • Medial side of foot to ball of the hallux • Lateral cutaneous of calf • Superficial peroneal • Sural, lateral border of foot • Deep peroneal first cleft

MOB TCD Fascial Compartments in Calf • Subcutaneous surface of tibia • Fascia anterior and posterior intermuscular septa • Anterior compartment • Lateral compartment • Posterior compartment Divided • Superficial • Deep posterior

MOB TCD Extensor Retinacula • • Superior retinaculum Thickening deep fascia Tibialis anterior pierces Other tendons pass posterior Inferior extensor retinaculum Inferior stem attached to calcaneus Upper limb to medial malleolus Lower limb plantar aponeurosis

MOB TCD Anterior Compartment of Calf • • • Tibialis anterior Extensor hallucis longus Extensor digitorum longus Peroneus tertius All muscles supplied by the deep peroneal nerve • Dorsi flexors • Anterior tibial and perforating peroneal arteries

MOB TCD Tibialis Anterior • Upper two thirds • Lateral surface of tibia and adjoining area of interosseous membrane • And deep fascia Inserted • Medial aspect of medial cuneiform • And adjoing base of first metatarsal

MOB TCD Tibialis Anterior • Synovial sheath • Passes under superior and both limbs of inferior extensor retinaculum • Dorsi flexor and invertor • Eccentric pays out, prevents foot slapping down • Supports medial arch • Deep peroneal nerve

MOB TCD Extensor Hallucis Longus • • Middle two fourths Anterior surface of fibula Interosseous membrane Base of distal phalanx of hallux • Dorsiflexor big toe and ankle • Deep peroneal nerve • Test for L 5

MOB TCD Extensor Hallucis Longus • Upper three quarter anterior surface of fibula • Except the area for the extensor hallucis longus • Anterior intermuscular septum • Passes under retinacula • Divides into four tendons • Joined by slips from brevis • Lumbricals and interossei muscles

MOB TCD Extensor Digitorum Longus • Main extensor tendon inserted into base of middle phalanx, of the lateral four toes • Collateral slips formed by lumbricals and interossei inserted into distal phalanx • Dorsiflexor ankle • Extends proximal phalanx lateral four toes

MOB TCD Peroneus Tertius • Lower quarter of anterior surface of the fibula • Inserted into base and dorsum of shaft of fifth metatarsal • Dorsiflexor and evertor

MOB TCD Extensor Digitorum Brevis • • • Fleshy origin from calcaneus Stem of inferior retinaculum Divides into four tendons First is extensor hallucis brevis Other three join extensor expansion of second, third and fourth toes • Deep peroneal nerve

MOB TCD Deep Peroneal Nerve • Branch of the common peroneal at neck of fibula • Pierces anterior intermuscular septum • Runs between extensor digitorum longus and tibialis anterior • Then tibialis anterior and extensor hallucis longus

MOB TCD Deep Peroneal Nerve • • In anterior compartment Supplies Tibialis anterior Extensor hallucis longus Extensor digitorum longus Peroneus tertius Extensor digitorum brevis Skin first cleft

MOB TCD Anterior Tibial Artery • Branch of popliteal • Enters above interosseous membrane • Only supply of tibialis anterior • Becomes dorsalis pedis at ankle joint

MOB TCD Dorsalis Pedis • • Gives off First dorsal metatarsal artery Arcuate artery gives off 2 -4 th dorsal metatarsal arteries • At base of first intermetatarsal space • Enters sole of foot • Joins lateral plantar artery to complete plantar arch

MOB TCD Blood Supply of Dorsum • Arcuate artery • Dorsal metatarsal arteries • Posterior and anterior perforating branches from metatarsals • Communicate plantar arch • And its digital branches • Perforating veins drain into dorsal venous arch

MOB TCD Perforating Peroneal Artery • • Perforating peroneal artery Pierces interosseus membrane Enters anterior compartment May replace dorsalis pedis

MOB TCD Venous and Lymph Drainage of Foot • Dorsal venous arch • Medial, long saphenous vein • Anterior to medial malleolus • Short saphenous vein • Posterior to lateral malleolus • Lymphatics follow superficial veins

MOB TCD Lateral Compartment of Calf • Between anterior and posterior intermuscular septa • Peroneus longus • Peroneus brevis • Superficial peroneal nerve

MOB TCD Peroneus Longus • Upper two thirds lateral surface of fibula • Adjoining area of interosseous membrane • Passes under superior and inferior peroneal retinaculum

MOB TCD Peroneus Longus • • • May have a sesamoid bone Runs in groove in the cuboid Inserted into Lateral aspect of medial cuneiform And adjoing base of first metatarsal

MOB TCD Peroneus Longus • • • Plantar flexor and evertor Supports lateral arch Superficial peroneal nerve Cuboid syndrome Torn peroneal retinacula Snapping tendons

MOB TCD Peroneus Brevis • Lower two thirds • Lateral surface of fibula in front of longus • Passes under superior and inferior peroneal retinacula • Above peroneal trochlea on calcaneus • Inserted into base of fifth metatarsal

MOB TCD Peroneus Longus and Brevis • Plantar flexors and evertors • Longus support the lateral longitudinal arch • Superficial peroneal nerve

MOB TCD Superficial Peroneal Nerve • • Branch common peroneal Neck of fibula Supplies peroneus longus and brevis Pierces deep fascia Dorsum of foot supplies Medial side of big toe All clefts except first and lateral side of little toe

Sensory Supply to Posterior Aspect of Calf • • • Posterior cutaneous nerve of thigh Lateral cutaneous of calf Sural nerve Saphenous nerve Medial calcaneal MOB TCD

MOB TCD Dermatomes

MOB TCD Posterior Surface of the Calf • Short saphenous vein • Posterior to lateral malleolus pierces the roof of popliteal fossa to enter popliteal vein • Deep fascia thickened medial between medial malleolus and calcaneum • Bursa anterior to achilles

Medial and Lateral Heads of Gastrocnemii • Medial head arises from popliteal surface of femur above medial condyle • Lateral is shorter, arises from posterior part of the lateral surface of the lateral femoral condyle and capsule of knee • Fabella is a sesamoid bone in lateral head MOB TCD

Medial and Lateral Heads of Gastrocnemii • • • Bursa deep to the two heads Medial belly is longer Unite to form a tendinous raphe Unites with soleus to form achilles Fast twitch fibres Flex knee and plantar flex ankle MOB TCD

MOB TCD Plantaris • Short fleshy origin from • The popliteal surface of femur above the lateral femoral condyle • Long tendon passes between gastronemii and soleus • Inserted medial border of achilles • Tibial nerve

MOB TCD Plantaris • • May be absent May rupture Used in tendon grafts Sudden dorsiflexion of ankle Ballet dancing Gymnastics Basketball Sprinting

MOB TCD Soleus • Broad flat pennate muscle • Arises from head and upper fourth of posterior surface of the fibula • Fibrous arch • Soleal line of tibia • Middle third of medial border of tibia

MOB TCD Soleus • • • Two aponeurotic lamellae Bulk of vascular multipennate muscle fibres Deepest of achilles Slow twitch fibres Perforating veins from great saphenous enter soleus • Acts as a peripheral pump

MOB TCD Achilles Tendon • Extent of the fusion between the gastronemii and soleus varies • Inserted into middle of posterior surface of the calcaneus • Tendon twists • Gastronemii form the lateral and posterior part of the tendon

MOB TCD Achilles Tendon • Rotation occurs above where the soleus tends to join • Rotation is greater if minimal fusion • Stress marked 2 -5 cm above insertion • Plantar flexor of ankle • Eccentric lower heels

MOB TCD Achilles Tendon • The achilles tendon is subjected to the highest loads in the body • Tensile loads up to eight and ten times body weight are experienced during running jumping hopping and skipping • The achilles tendon is subjected to stress when running up and downhill • A tight achilles tendon also limits dorsiflexion of the ankle

MOB TCD Achilles Tendon • Superficial bursa may be found posterior to achilles between it and the deep fascia • The retrocalcaneal bursa is just proximal to the insertion • Between the tuberosity on the posterior surface of the calcaneus and the achilles tendon

MOB TCD Achilles Test

Medial and Lateral Heads of Gastrocnemii • • • Sprinting Jumping Hopping Skipping Stretched with knee extended ankle dorsiflexed • Tibial nerve MOB TCD

MOB TCD The Retrocalcaneal Bursa • The area of fibro cartilage on the tendon forms the posterior wall • The anterior wall of the retrocalcaneal bursa is the 0. 5 to 1 mm thick cartilaginous layer on the posterior aspect of the calcaneus • The proximal wall of the synovial lined sac consists of folds, or villus synovial projections • Allows alterations in its form, produced by varying degrees of pressure on the fat above it during flexion and extension of the ankle

MOB TCD Flexor Digitorum Longus • • Posterior surface of tibia Below soleal line Medial to vertical line Variable origin by an aponeurosis from fibula

MOB TCD Flexor Digitorum Longus Very extensive fibular origins of FDL Hislop M, 2003 FHL Fibular origin of FDL

MOB TCD Flexor Digitorum Longus • Crosses tibialis posterior in calf • Flexor hallucis longus in foot • Foot receives insertion flexor accessorius and two slips from flexor hallucis longus • Divides four tendons • Give origin to four lumbricals

MOB TCD Flexor Digitorum Longus • In the foot the tendon passes through birfurcation of brevis • Inserted into distal phalanges • Plantar flexes ankle • Plantar flexes lateral four toes • Supports medial arch • Tibial nerve

MOB TCD Flexor Hallucis Longus • Bulkiest and most powerful, multipennate • Arises from posterior surface of fibula • Posterior to medial crest • Beef to heel • Most posterior under retinaculum

MOB TCD Flexor Hallucis Longus • Grooves posterior process of talus • Sustentaculum tali • Crossed in foot by flexor digitorum longus to which it gives two slips • Inserted base of distal phalanx

MOB TCD Flexor Hallucis Longus • • • Tibial nerve Plantar flexes ankle Flexes big toe Supports medial longitudinal arch Take off muscle

MOB TCD Tibialis Posterior • • • Deepest Posterior surface of tibia Below soleal line Lateral to vertical line Interosseous membrane Arises from posterior surface of fibula • Anterior to medial crest

MOB TCD Tibialis Posterior • Crossed by flexor digitorum longus in calf • Posterior to medial malleolus grooves bone, type II collagen, tends to have poor blood supply • Most anterior under the flexor retinaculum • Inserted into tuberosity of navicular • All bones of the tarsus except talus • Base of middle three metatarsals

MOB TCD Tibialis Posterior • • Plantar flexor ankle Invertor of foot Supports medial arch Avascular area behind medial malleolus • Tibial nerve

MOB TCD Posterior Tibial Artery • Branch popliteal artery • Lower border of popliteus • Under fibrous arch of soleus • Between flexor digitorum longus and flexor hallucis longus • Vena commitans

MOB TCD Posterior Tibial Artery • • In the calf gives off Nutrient artery to tibia Peroneal artery Nutrient artery to fibula Perforating peroneal Passes under flexor retinaculum Gives off medial calcaneal artery which pierces flexor retinaculum • Then ends under flexor retinaculum • Dividing into medial and lateral plantar arteries

MOB TCD Tibial Nerve • • • Leaves the popliteal fossa Runs in middle of calf Deep to soleus Accompaning artery Branches to soleus Flexor digitorum longus and flexor hallucis longus • Tibialis posterior

MOB TCD Flexor Retinaculum • • • Medial malleolus to calcaneus Anterior to posterior Tibialis posterior Flexor digitorum longus Posterior tibial artery Medial calcaneal artery pierces retinaculum Divides into medial and lateral plantar arteries Tibial nerve Gives off medial calcaneal nerve which accompanies artery Divides into medial lateral plantar nerves Flexor hallucis longus

MOB TCD Causes of Compartment Syndromes • • • May be acute or chronic Sudden increase in exercise Haematoma Callus Fracture

MOB TCD Compartment Syndromes • Mainly anterior compartment • Tibialis anterior main muscle affected as only supplied by anterior tibial, other muscles also supplied by perforating peroneal • Increasing pressure causes loss of sensation of first cleft due to pressure on deep peroneal nerve • Fasciotomy Or • Posterior or lateral compartments

MOB TCD Posterior Compartment • Posterior compartment • Posterior border of tibia • Posterior intermuscular septum Divided • Superficial • Deep posterior

MOB TCD Posterior Compartment • Superficial compartment • Posterior intermuscular septum • Posterior border of tibia

MOB TCD Superficial Posterior Compartment • • • Medial and lateral gastrocnemii Plantaris Soleus Forming the achilles tendon Tibial nerve

MOB TCD Deep Posterior Compartment • • Popliteus Flexor digitorum longus Flexor hallucis longus Deepest is tibialis posterior

Chronic Exertional Compartment Syndrome (CECS) • Significant morbidity/limitation activity to athletes • Activity related, reversible, myofascial intracompartmental pressure increase • Results in decreased tissue perfusion and neuromuscular function abnormalities • Predilection for the lower leg MOB TCD

Chronic Exertional Compartment Syndrome (CECS) § The fibular origin of FDL can partially (or sometimes almost completely) compartmentalize TP and acts to resist increases in intracompartmental volume and therefore cause increased pressure § The presence and extent of a fibular origin of FDL may act as an anatomical predisposition to the development of CECS MOB TCD

“BMJ Publishing Group Limited (“BMJ Group”) 2012. All rights reserved. ”