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

Indecent Ian Gets Laid On Fridays Luckily Ilio-inguinal, ilio-hypogastric, genito-femoral, lateral cut., obturator, femoral, lumbosacral trunk

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 2 options Upper outer to avoid sciatic 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 Unhappy Triad from lateral blow 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 Contents 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 MILC Talus Calcaneus Navicular Medial cuneiform Intermediate cuneiform Lateral cuneiform Cuboid

Venous drainage Great Saphenous vein Small 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 Popliteal pulse Posterior tibial 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 3,4 Kneel on the floor 5, 6 Pick up sticks 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