Lower Limb Anatomy

Learning Objectives

Clinical Anatomy and Imaging

Major bony features

Major muscles/muscle groups

Landmark tendons

Major neurovascular structures at key locations

Borders and major contents of the axilla, cubital fossa, anatomical snuffbox, carpal tunnel, femoral triangle, popliteal fossa, tarsal tunnel

Ilio-inguinal, ilio-hypogastric, genito-femoral, lateral cut., obturator, femoral, lumbosacral trunk

Indecent Ian Gets Laid On Fridays Luckily

Muscles – Gluteus maximus, medius, minimus, Piriformis, gemellus superior and inferior, quadratus femoris, obturator internus

Superior gluteal artery – glutes

Inferior gluteal artery – the rest

Superior gluteal nerve (L4,5,S1) – glute med and min

Inferior gluteal nerve (L5,S1,S2) – glute max

Nerve to quad fem (L5,S1) – quad fem, gem inf

Nerve to obturator internus (L5, S1) – obturator internus, gem sup

Piriformis gets branches from L5,S1,S2

Injections

Vertical line from peak of iliac crest

2 options

Line from PSIS to greater trochanter

Horizontal line midway from iliac crest to ischial tuberosity

Upper outer to avoid sciatic

Hip Joint Type - Ball and Socket

Articular surfaces – femoral head, acetabulum

Ligaments – iliofemoral, pubofemoral, ischiofemoral, transverse acetabulum, ligamentum teres

Bursa – iliopsoas, trochanteric, gluteus medius, ischiogluteal

Vascular – capsular retinacula vessels (medial and lateral circumflex), artery of ligamentum teres, nutrient artery

Nerve – obturator, femoral, sciatic

Movements – flexion, extension, abduction,

adduction, rotation (medial, lateral)

Hip problems

Elderly lady, shortened and externally rotated leg

Fractured NOF

Avascular necrosis

Poor blood supply

Sub-capital, intracapsular

Head on collision in a car, loss of sensation in foot

Posterior dislocation compressing sciatic nerve

Femoral Triangle Borders – Inguinal ligament, medial margin of

Sartorius, medial margin of adductor longus.

Floor – pectinues, adductor longus, iliopsoas

Contents

Nerve

Artery (within 1.5cm of mid-inguinal)

Vein

Y-fronts

Mid-inguinal point – ASIS to pubic tubercle

Anterior compartment of the Thigh

Muscles – Iliacus, Psoas, Sartorius, Rectus femoris, Vastus lateralis, intermedius and medialis (rectus and vasti = quadriceps femoris)

Femoral nerve L2-4 (Iliopsoas L1-3)

Knee extension, hip flexion

Femoral artery and vein

Medial Compartment of Thigh Muscles – Obturator externus,

Pectineus, Gracilis, Adductor magnus, brevis, longus

Nerves – Obturator nerve L2-4

Blood supply

Adduction

Adductors medially rotate at hip

Obturator laterally rotates at hip

Gracilis and pectineus flex

Posterior compartment of thigh

Muscles – SemiMembranosus (medial), semiTendinosus (on top), biceps femoris

Sciatic nerve (L5-S2)

Blood supply

Flex at knee, extend at hip, rotation

Knee Joint Type – Synovial hinge joint

Articulation – femur, tibia, patella

Ligaments

Intracapsular - Cruciates, meniscofemoral

Extra – patella, collaterals, oblique, arcuate, popliteal

Movements – flexion, extension

Blood – genicular anastomosis

Nerves – femoral, obturator, sciatic

Extras – Menisci, bursae (pre-, infra-, suprapatellar)

Knee

Locking mechanism

Inferior aspect of femoral condyles are large and flat increased surface area + therefore stability

Femur medially rotates in extension which tightens ligaments

Centre of gravity anterior to knee, keeping joint locked

Popliteus laterally rotates the femur, unlocking the joint

Unhappy Triad from lateral blow

ACL, MCL, medial meniscus

ACL – prevents anterior movement of tibia on femur

PCL – prevents posterior movement of tibia on femur

Popliteal Fossa

Borders

Semimembranosus

Biceps femoris

Medial and lateral head of gastrocnemius

Contents

Medial to lateral – Popliteal artery, popliteal vein, tibial nerve, common fibular nerve

Posterior compartment of the leg

Gastrocnemius, Soleus

Popliteus, Tibialis

posterior, flexor digitorum

longus, flexor hallucis

longus,

Posterior tibial artery

Tibial nerve

Plantar flexion of foot and

toes

Anterior Compartment of the Leg

Muscles – Tibialis anterior, extensor digitorum longus, extensor halluces longus, fibularis tertius

Deep fibular nerve (L4, L5, S1)

Anterior tibial artery (runs between tibial tuberosity and fibular head)

Dorsiflexion of foot and toes, tibialis inverts

Lateral compartment of the leg Muscles – Fibularis longus, fibularis brevis

Superficial fibular nerve (L5, S1, S2)

Fibular artery

Eversion of the foot, longus helps plantarflex

Injury to lateral leg

What nerve will be injured and what will be the presentation?

Common fibular nerve, foot drop

Tarsal Tunnel – Tom, Dick And Very Nervous Harry Roof - Flexor retinaculum; Floor - medial surfaces of talus and

calcaneus

Foot

Tiger Cubs Need MILCTalusCalcaneusNavicularMedial cuneiformIntermediate cuneiformLateral cuneiformCuboid

Venous drainage Great Saphenous vein

Medial foot from dorsal venous arch

Small Saphenous vein

Lateral foot from dorsal venous arch, superficial posterior leg, joins popliteal vein in fossa

Popliteal vein becomes femoral vein

Femoral triangle

External Iliac veins

Great Saphenous vein

Medial foot from dorsal venous arch

Small Saphenous vein

Lateral foot from dorsal venous arch, superficial posterior leg, joins popliteal vein in fossa

Popliteal vein becomes femoral vein

Femoral triangle

External Iliac veins

Pulses Femoral pulse

Mid-inguinal point

Popliteal pulse

Popliteal fossa, medial side, artery deepest structure in fossa so push hard

Posterior tibial pulse

Located posterior and inferior to medial malleolus

Dorsalis pedis pulse

Dorsum of foot, between tendons of extensor hallucis longus and extensor digitorum longus to second toe

Dorsalis pedis artery from anterior tibial artery

Reflexes 1,2 Buckle my shoe

S1, 2 Achilles tendon

3,4 Kneel on the floor

L3, 4 Patella tendon

5, 6 Pick up sticks

C5, 6 Biceps tendon

7, 8 I’m great

C7, 8 Triceps tendon

Compartment Syndrome

Increase in pressure within a fascial compartment due to increase in fluid

Signs – 6P’s

Pallor

Pulselessness

Paraesthesia

Paralysis

Pain

Perishingly cold