Anatomy - leg foot and ankle Flashcards
What do you call the common accessory bone of the talus?why does it form?
Os trigonum. unfused posterior process (lateral tubercle)
What attaches to the posterior process of the talus?
Posterior talofibular ligament. It attaches to the lateral tubercle of the posterior process
What runs in the posterior process of the talus?
Tendon of FHL - between lateral and medical tubercles
What structure wraps directly under the sustentaculum?
FHL tendon
What runs in the sinus tarsi? Name all structures.
Interosseous talocalcaneal ligament (cervical ligament)artery of tarsal sinus(artery of tarsal canal runs in the canal, which is the continuation of the sinus)
Describe the blood supply to the talus. What is the main supply?
all 3 terminal arteries:posterior tibial a. (MAIN SUPPLY) - deltoid branch to BODY, artery of tarsal CANALdorsalis pedis a.–branch to dorsal head/neck, contributes to artery of tarsal SINUSperforating peroneal a. - contributes to artery of tarsal SINUS - supply head/neck, lateral body
What is the Lisfranc ligament?
Interosseous portion of the oblique ligament from medial cuneiform to 2nd MT base
What are the components of the Lisfranc ligament? which is the strongest one? weakest?
Dorsal (weakest), plantar and interosseous (strongest)
What is the Chopart joint?
The midtarsal joint, comprising the talonavicular & Calcaneocuboid joints
What are the ligamentous components of the ankle syndesmosis?
AITFLPITFLInterosseous membrane (IoM)Interosseous ligament (IoL)Inferior transverse ligament (ITL) (really just the distal fibrocartilagenous component of the PITFL)
What are the components of the deltoid ligaments of the ankle?
Superficial: - Tibionavicular & TibiocalcanealDeep: - Anterior & posterior tibiotalar
What is an Os Navicular? What are the types?
Accessory navicular. Type 1: Sesamoid within the distal part of the tendonType 2: Attachment to the posterior tibialis tendon, separated by synchondrosistype 3: enlargement of navicular
What benign structure can often be confused with a Lisfranc Injury?
Os metatarsum
What is an os metatarsum?
Accessory bone found between the medial cuneiform and 1st/2nd metatarsals
What are the plantar layers of the foot?
4 layers:1st: - Abductor hallucis brevis - Abductor digiti minimi - Flexor digitorum brevis , plantar fascia2nd: - Quadratus plantae - Lumbricals , FHL and FDL tendons3rd: - Flexor hallucis brevis - Flexor digiti minimi brevis - Adductor hallucis4th: - Dorsal interossei - Plantar interossei (also tendons of per longus and tib post)
What are the muscles in the dorsal intrinsic compartment of the foot?
Extensor hallucis brevisExtensor digitorum brevis
What is the Master Knot of Henry? Why is it important?which of the two structures is dorsal/volar?
Crossing between the FHL and FDL in the footImportant as dividing it allows access to the deeper layers of the foot and because it can be a site of graft harvest (either FHL or FDL tendon transfers)FHL is dorsal to FDL
What are the compartments of the foot and their key structures?
Hindfoot:Calcaneal: quadratus plantae, posterior tibial NAV, lateral plantar NAV, +/- medial plantar nerveForefoot:Interosseous x4 - each has an interosseiAdductorFull length: Superficial: FDB, lumbricals, FDL tendons +/- medial plantar nerveMedial: FHB, AbHLateral: AbDQ, FDM
What are the borders and contents of the tarsal tunnel?
Floor: medial talus, sustentaculum tali, medial calcaneal wallRoof: Lacinate ligament (flexor retinaculum)Contents:TP, FDL, PT artery, vein, Tibial nerve, FHL”Tom Dick And Very Nervous Harry”
What is Baxter’s Nerve? What is it’s clinical significance?
1st branch of the lateral plantar nerveIt runs obliquely on top of quadratus plantaeIt’s a cause of medial heel pain if impinged (dDx of plantar fascitis)
Where does the Plantaris tendon insert? be specific.
Medial to the achilles tendon. It may be a part of the achilles tendon but it will still be on the medial side
What structures combine to form the Sural Nerve?
Medial and lateral sural cutaneous nervesLateral: branch of common peroneal nerveMedial: branch of tibial nerve
What does the Sural nerve run with? On which side is the nerve?
Runs with short saphenous vein and it is lateral to it
Where does the superficial peroneal nerve pierce the fascia and become subcutaneous?
10-12cm proximal to the tip of the lateral malleolus
What parts of the talus articulate with the calcaneus?
Anterior, middle and posterior articular surfaces
Describe the posterolateral approach to the Ankle:
Position: Prone or supine w/ large bump Incision: posterior border of fibula, centered around fracturePlane: FHL (tibial) & peroneal muscles (sup. peroneal)can also go anterior to peroneals depending on target anatomyDangers: Do not take off PITFL (devitalizes segments), Sural nerve
Describe the posteromedial approach to the ankle:
Position: supine Incision: 10cm longitudinal anteriorly curved incision Plane: pick optimal interval:Tibialis posterior & flexor digitorum longus (both tibial) ORFHL and NV bundle ORFDL and NV bundleDangers: posterior tibial artery and vein, tibial nerve
Describe the anterior approach to the ankle:
Position: supineIncision: 15cm incision over ankle joint, between the 2 malleoli, beginning 10cm proximal to ankle jointPlane: EHL & EDL (both deep peroneal)Dangers: Superficial peroneal nerve, Neurovascular bundle
Where does the neurovascular bundle of the anterior compartment of the leg run above and below the ankle joint level?
Bundle includes deep peroneal nerve and anterior tibial arteryAbove joint, runs between EHL and tib-ant.At the joint, crosses behind extensor hallucis longus then below, it runs between EHL and EDB (EDB is bit more medial than EDL)
What is the innervation of peroneus tertius?
Deep peroneal nerve
what are normal ankle syndesmosis measurements on XRay? what views?
tib/fib clear space tib/fib overlap >6mm on AP, >1mm on mortisetalocrural angle 79-87 degreesmedial clear space 4mm or less on mortise
Lisfranc ORIF vs Arthrodesis. Whats the evidence?
Ly and Coetzee performed a Level 1 investigation of 41 patients with an isolated acute or subacute Lisfranc dislocation treated with ORIF or primary arthrodesis of the medial column of midfoot. Two years postoperatively, the mean AOFAS Midfoot score was 68.6 points in the open-reduction group and 88 points in the arthrodesis group (p
How much of the talus is covered with articular cartilage?
60%
What are parts of the posterior process of the calcaneus? What attaches here?
Medial and lateral tubercles- Posterior talocalcaneal ligament attaches to lateral tubercle
What are the different facets of the body of the talus?
medial, lateral and posterior
What bony structure supports the middle articular facet of the talus?What attaches to it and runs underneath it?
Sustentaculum taliAttachments:Anteriorly: plantar calcaneonavicular ligamentMedially: deltoid ligamentFlexor hallucis longus runs in a groove under it - FHL runs between the medial and lateral tubercles of the posterior process of the calcaneus and then runs under sustentaculum tali of the medial calcaneus
From medial to lateral, what are the order of theextrinsic extensor tendonsto the ankle distal to ankle joint?
Tibialis anterior, EHL, EDL, Per Tertius (EDB is intrinsic)
What bones does the talus articulate with?
4 bones:- Tibia: via trochlea and medial articular process- Fibula: via the lateral aticular facet- Calcanues- Navicular
What are the talar and calcaneal bony components of the sinus tarsi?
Talar: sulcus tali (talar sulcus)Calcaneus: calcaneal sulcusThese 2 halves form the sinus tarsi
What is the sinus tarsi? What are its boundaries?
Anatomical space that is medially continuous with the much narrower tarsal canalBoundaries: Superior: talusInferior: calcaneusAnterior: talocalcaneonavicular jointPosterior: posterior facet of the subtalar joint
What inserts into the navicular tuberosity?
Tibialis posterior
What 2 muscles attaches to the medial cuneiform and first metatarsal of the foot?
Tibialis anterior, peroneus longus
What constitutes the deltoid ligaments of the ankle?
Medial ligament complex of the ankle 2 layers:Superficial: tibionavicular & tibiocalcaneal ligamentsDeep: anterior and posterior tibiotalar ligaments
What constitutes the lateral fibular ligaments of the ankle? which is weakest? strongest?
Anterior talofibular ligament (ATFL) - weakest - an intracapsular thickeningPosterior talofibular ligament (PTFL) - deepest, strongest Calcaneofibular ligament(CFL) - longest - narrow cord covered by peroneus longus and brevis
What position will tighten the anterior talofibular ligament (ATFL)?
Plantarflexion- So it’s crucial to make sure position is correct with testing
What position will tighten the calcaneofibular ligament (CFL)?
Inversion in neutral flexion
What is the origin and insertion of the spring ligament?
AKA plantar calcaneonavicular ligament- Origin: sustantaculum tali- Insertion: navicular
Which is stronger, deltoid complex orthe lateral fibular ligaments?
Deltoid are stronger - Remember, it’s easier to have an inversion injury of the ankle
What is the lisfranc ligament?
Oblique interosseous ligament between MEDIAL cuneiform and 2nd MT- Strongest of the lisfranc ligaments
What is the order of failure of the lisfranc ligament?
Dorsal, then plantar, then interosseous- Interossous is the strongest component of the lisfranc ligament
What is an os intermetatarseum and what should it not be confused with?
Accessory bone found between the medial cuneiform and 1st/2nd metatarsal bases- May be independent or an exostosis-like process- Should not be confused with a fracture of the base of the 2nd MT in a lisfranc injury
How do you tell the difference between a fractured hallux sesamoid and a bipartite hallux sesamoid?
The 2 fracture fragments of a sesamoid fit together wheras a bipartite does not…- And also clinically (pain)
What is the innervation of the dorsal intrinsic layer of the foot?
Deep peroneal nerve
Describe the compartment release of the foot
midfoot dorsal incision over MT 2 (open interosseous compartments between 1,2 and 2,3)and MT4 (open interosseous compartment between 3,4 and 4,5)medial calcaneus incision to access calcaneal compartment and all full length compartments (medial, lateral, superficial
What are the borders of the tarsal tunnel? It’s contents?
Floor: medial talus, sustentaculum tali, medial calcaneal wallRoof: Lacinate ligament (flexor retinaculum)Contents: Tom, Dick And Very Nervous Harry
What are the branches of the tibial nerve?
3 branches- Medial calcaneal branch- Medial plantar nerve- Lateral plantar nerve - 90% of the time, bifurcation is within the tarsal tunnel, otherwise, it’s proximal to it
what is the:chaput fragmentVolkmann fragmentWagstaff fragment
Chaput fragment: anteriolateral tubercle of the tibiaWagstaff fragment: anterior tubercle of the fibulaVolkman’s fragment: posterolateral tubercle of the tibia
What is the constant fragment in the tibia? calcaneus? Why is it called that?
Volkman’s fragment (posterolateral tubercle of the tibia)orsustentaculum fragment in a calcaneusCalled that b/c in a pilon fracture, it stays in it’s anatomic location, being “constant” - only if fibula already anatomically reduced. You can use it to build off of.similiarly in a calc frx
What is the OI of the Bifurcate ligament?
Calcaneocuboid/calcaneunavicular ligamentO: CalaneusI: cuboid/navicular
What is the OI of the long plantar ligament?
Calcaneocuboid-metatarsal ligamentO: calcaneusO: Cuboid & 1st-5th MT
What is the OI of the short plantar ligament?
Plantar calcaneocuboid ligamentO: calcaneusI: Cuboid
What is the OI of the spring ligament?
Plantar calcaneonavicular ligamentO: CalcaneusI: Navicular
What is Morton’s neuroma?
Neuroma of a digital nerve, most commonly between 2nd/3rd MT
What is the primary stabilizer of the MTP joints?
Plantar plate (primary stabilizer)Also collaterals: MCL/LCL
What muscle inserts onto the tibial and fibular sesamoids of the 1st MT head?
FHB
Peroneus longus runs anterior/posterior to brevis through the fibroosseous tunnel?
Posterior
What is the primary restraint to lateral instability of the peroneal tendons?
Superior peroneal retinaculum, 3.5mm proximal to the tip of the distal fibula
What is the OINA of extensor digitorum brevis?
O: superolateral calcaneusI: base of proximal phalangesN: Deep peroneal nerveA: Extends MTPJ
What is the OINA of extensor hallucis brevis?
O: Superolateral calcaneusI: Base of proximal 1st phalanxN: Deep peroneal nerveA: Extends great toe MTPJ
Plantar Aponeurosis OI:
O: Calcaneal tubercleI: thick fibrous structure sending slips to each of the toes
OINA abductor hallucis
O: Calcaneal tuberosityI: Base of great toe, proximal phalanxN: Medial plantarA: Abducts great toe
OINA Flexor digitorum brevis
O: Calcaneal tuberosityI: middle phalanges of 2-5th toesN: Medial plantarA: Flex toes at PIPJanalagous to FDS of the hand - it splits to allow FDL tendon passing thru to distal phalanx
OINA abductor digiti minimi
O: Calcanea tuberosityI: Base of 5th toe (prox phal)N: Lateral plantarA: Abducts 5th toe
OINA lumbricals
O: FDL: medial sideI: proximal phalanx: medial sideN: medial and lateral plantar nervesA: Flex MTP, extend IP (same as in hand)
OINA Quadratus plantae
O: Medial and lateral calcaneusI: FDL tendonN: Lateral plantar nerveA: Flex distal phalanges
OINA flexor hallucis brevis
O: Cuboid, lateral cuneiformI: Proximal phalanx great toeN: Medial plantarA: flex great toe
OINA adductor hallucis
O: Oblique head: 2-4th proximal MTtransverse head: plantar MTP lig of 3-5I: Lateral proximal phalanx great toeN: Lateral plantar nerveA: adduct great toe
OINA flexor digiti minimi brevis
O: Base 5th MTI: 5th toe, proximal phalanxN: Lateral plantar nerveA: Flex 5th MTPJ
OINA dorsal interossei?
x4O: MetatarsalsI: Dorsal extensorsN: Lateral plantar nerveA: abduct toes
OINA plantar interossei
x3O: 3-5th MTI: Proximal phalanges mediallyN: Lateral plantar nerveA: Adduct toes
What are the terminal branches of the tibial nerve?
Medial calcanealMedial plantarLateral plantar
Where does the tibial nerve bifurcate into its terminal branches?
90% of the time, bifurcation is within tarsal tunnelOtherwise, proximal to it
What innervates the plantar foot muscles?
Tibial nerveMedial plantar nerve: medial foot:- Abductor hallucis brevis- FDB- FHB- 1st lumbricalLateral plantar nerve: all the rest
What are the terminal branches of the tibial artery?
Medial and lateral plantar arteries- These follow the same path as the corresponding nerves
Name and describe the windows of the posteromedial approach to the ankle
Lateral to FHL:- Between FHL (medial) and peroneals (lateral)Medial to FHL:- Between FHL (lateral) and NV bundle (medial)- Between FHL/NV bundle (lateral) and FDL (Medial)Cut all tendons
Describe the arthroscopic portals for ankle arthroscopy and their main dangers
Anterolateral portal:Medial to lateral malleolus, lateral to peroneus tertiusDanger: dorsal intermediate cutaneous branch of superficial peroneal nerveAnteromedial portal:Medial to tibialis anterior and lateral to medial malleolusDanger: Saphenous nerve & veinPosterolateral portal:Medial to peroneal tendons, lateral to achillesDanger: sural nerve, small saphenous veinPosteromedial portal:Can injure posterior tibial artery
Describe the course of the dorsalis pedis artery?
Continuation of Anterior tibial arteryTravels down foot lateral to EHLGives off branches:Medial and lateral Tarsal branhcesArcuate artery: passes over dorsal TMT joint, deep to tendonsDeep Plantar artery - large branch that dives deep through 1st/2nd webspace at MT bases- This forms the deep plantar archDP ends as digital arteries
what muscle(s)/tendon(s) attach to the talus?
nothing
cuboid has a groove along its plantaraspect - what runs in it?
peron. longus
proximal tibia fractures deform into what position?why?
procurvatum (quads tendon) and valgus (Pes anserinus)
what does the lateral compartment of the leg contain?
peroneus longusperoneus brevissuperficial peroneal nerve(no arteries)
what neurovascular bundle(s) are in the deep posterior compartment of the leg? Name each component
tibial nerve, posterior tibial artery, posterior tibial veinsperoneal artery and veins
describe the path of the tibial nerve from start to finish
starts as bundle of the sciatic nerve which splits into tibial nerve and common peroneal nerve at top of popliteal fossatibial nerve gives off medial sural cutaneous nerve in popliteal fossa, then goes between heads of gastroclies superficial to plantaris and popliteusdives deep to soleus through fibrous archenters deep posterior compartment, travels just deep to transverse IM septumruns with posterior tibial a and v, between FHL and FDLstays between them and wraps behind medial malle in tarsal tunnelgives off calcaneal branchenters tarsal tunnel, bifurcates into medial and lateral plantar nervesexits tunnel (both) and runs between 1st and 2nd plantar layerMPN is deep to abductor hallucisLPN is obliquely superficial to quad plantaeLPN gives off baxter’s nerve
descreibe the sensory distribution of the plantar foot–be specific
central and medial heel: medial calcaneal branch of tibial nervelateral foot and heel: sural nervemedla foot: saphenous nerveD1-half of D4: medial plantar nerveD5 to half of D4: lateral plantar nerve
describe the path of the common peroneal n.
branches from sciatic nerve at top of popliteal fossaruns posterior to bicep sfemoris tendoncrosses superfiical to lateral head of gastrochere it gives off lateral sural cutaneous nervemain nerve continues just lateral to soleus and winds around fibular neck, deep to peroneus longusdivides into sup and deep per. n.
describe the path of the deep peroneal n from start to finish
common peroneal n splits deep to peroneus longus after wraps around fibular neckdeep peroneal n pierces the anterior IM septum (going from lateral to anterior compartment) and travels along anterior surface of IOMtravels with anterior tibia a and branches to each muscle in that compartmentpasses deep to the extensor retinaculums (superior and inferior)above ankle joint, travels between tib-ant and EHLcrosses under EHL at ankle and below it travels between EHL and EDLcontinues down to first web space for senation
describe the path of the superficial peroneal n from start to finish
branches from common peroneal deep to peroneus longus.continues here within superficial compartment up against anterior IM septumtravels along lateral fibula for proximal 1/3then between per longus and brevisheads anterior distally and travels between EDL and per brevis (still within superficial compartment, along IOM)pierces fascia 10-12cm above lateral malleolus to become superifical within fatjust anterior to fibulabifurcates (variable location) into medial dorsal cutaneous n. (supplies medial foot dorsum) and intermediate dorsal cutaneous n (supplies lateral foot dorsum
describe the path of the sural nerve from start to finish (all branches and how they relate)
common peroneal n gives off lateral sural cutaneous n in popliteal fossa and then travels subcutaneously along lateral gastroctibial n gives off medial sural cutaneous n in popliteal fossa which travels between heads of gastroc along with short saphenous v DEEP to deep fascia (no sensory fxn yet)pierces fascia in middle of calf to become subcutaneousjoins up with a branch from lateral sural cutaneous - becomes the sural nerve itselfsural n travels with short saphenous v (lateral to v) and runs between lateral malle and achilles - more proximal=closer to achilles, more distal=closer to lateral mallegives off lateral calcaneal branchesterminates as lateral dorsal cutaneous n on latedral side of foot/5th toe
describe the path of the saphenous nerve from where it exits hunter’s canalto finish
exits hunter’s canal, becomes subcutaneousgives off infrapatellar branch that crosses inferior to patellathe rest travels as medial cutanous nerve of leg AKA medial crural cutaneous branchessupplies sensation to medial leg, running with great saphenous veincontinues just anterior to medial malle to innervate skin on medial/dorsal foot.
describe the path of the great saphenous vein
starts as dorsal vein of hallux and merges with dorsal venous archpasses anterior to medial malle (with saphenous n) and goes up medial side of legat level of knee, lies posterior to medial epicondylegoes up medial thighpasses through fossa ovalis AKA saphenous openingdrains into femoral vein
describe the path of the popliteal artery
superficial femoral artery becomes popliteal artery when it enters popliteal foss abetween biceps and semi-Min popliteal fossa (lateral to medial)tibial n, pop v, pop ARTERY (most medial)lies behind posterior horn of lateral meniscus, about 9mm from the posterior tib plateau with knee flexed to 90superfiical to popliteus (like popliteal n)deep to gastroc/soleus, passes under fibrous arch of soleusbifurcates at distal aspect of poplitues into anterio tibial a. and tibioperoneal trunktibioperoneal trunk divides into posterior tiibal a. and peroneal a about 2.5cm below pop fossa
describe the path of the anterior tibial artery
branches from popliteal artery and passes between 2 heads of tib postpierces IOM into anterior compartmentruns down with deep peroneal n (medial to nerve) along anterior aspect of IOMfirst branch: anterior tibial recurrent arterystays between EHL and tib ant until anklecrosses under EHL at ankle then lies between EHL and EDLbecomes dorsalis pedis artery
describe the path of the posterior tibial artery
tibioperoneal trunk divides, giving off posterior tibial artery (deep to soleus, superficial to tib post but within deep posterior compartment)posterior tibial artery runs with tibial nerve, still superficial to tib postgives off nutrient artery to tibia itselffollows path of tibial nerve- becomes medial and lateral plantar arteriesat tarsal tunnel - tom dick And very nervous harry
describe the path of the peroneal artery
tibioperoneal trunk giveso ff this branch, superficial to tib post, deep to soleusstays within deep posterior compartmentruns deep to FHLbecomes perforating peroneal artery - passes from posterior to anterior compartment through IOMsupplies talusgives off lateral calcaneal branch
what muscles does the medial plantar n supply?
abd hallucisfdbfhb1st lumbrical(all others on plantar foot supplied by lateral plantar n)
