Week 12 Anterior & Medial Thigh - Nerves.pdf

Anterior and Medial Compartments of the Thigh Cutaneous Innervation of the Thigh  anterior surface of thigh, immediately below inguinal ligament (from lateral to medial):  lateral cutaneous branch of subcostal nerve  femoral branch of genitofemoral nerve...

Anterior and Medial Compartments of the Thigh Cutaneous Innervation of the Thigh  anterior surface of thigh, immediately below inguinal ligament (from lateral to medial):  lateral cutaneous branch of subcostal nerve  femoral branch of genitofemoral nerve  ilioinguinal nerve  remaining of anterior surface of thigh:  lateral cutaneous nerve of thigh (lateral femoral cutaneous nerve): supplies skin along lateral aspect of thigh  anterior cutaneous nerves of thigh (anterior femoral cutaneous nerves): branches of femoral nerve and supply skin of anterior and medial aspects of thigh  anterior branch of obturator nerve: supplies a small area of skin on medial aspect of thigh  posterior surface of thigh:  posterior cutaneous nerve of thigh (posterior femoral cutaneous nerve) Superficial Veins  located in superficial fascia  Great saphenous vein:  originates from medial end of dorsal venous arch of foot and ascends anterior to medial malleolus and along medial aspect of leg (with saphenous nerve) and passes posteromedial to knee joint (approximately a hand’s breath posterior to medial border of patella) and runs superiorly along medial aspect of thigh and in upper thigh passes through saphenous opening (opening in fascia lata) and drains into femoral vein  connected to deep veins via several perforating veins along its course and blood normally flows from superficial to deep veins through these perforating veins (valves prevent flow in opposite direction) and if valves become incompetent, perforating  veins leak blood during muscular contraction and superficial veins become dilated and varicose  small saphenous vein:  originates from lateral end of dorsal venous arch of foot and passes inferior and then posterior to lateral malleolus and in lower ⅓ of leg, it lies just lateral to calcaneal (Achilles) tendon and as it ascends in leg, it inclines slightly medially to reach midline of calf and pierces crural fascia (dep fascia of leg) in middle or upper ⅓ of leg and drains into popliteal vein  along its course in foot and leg it is accompanied by sural nerve  connected to deep veins of leg via perforating veins and also communicates with great saphenous vein Femoral Triangle  triangular, depressed area in upper part of anterior thigh  boundaries:  superior: inguinal ligament  lateral: medial border of sartorius  medial: medial border of adductor longus (some authors consider lateral border of adductor longus as medial boundary)  femoral triangle is continuous inferiorly with adductor (subsartorial) canal  floor (from lateral to medial): iliopsoas, pectineus and adductor longus muscles  roof: overlying fascia lata  contents: lateral cutaneous nerve of thigh, femoral nerve and artery and their branches, femoral vein and its tributaries, femoral branch of genitofemoral nerve, deep inguinal lymph nodes, adipose tissue Adductor (Subsartorial, Hunter’s) Canal  intermuscular space located on medial aspect of middle ⅓ of thigh  begins superiorly at apex of femoral triangle and ends inferiorly at adductor hiatus  triangular in cross-section there are 3 walls:  medial wall: sartorius  anterior wall: vastus medialis   posterior wall: adductor longus and adductor magnus  contents: femoral artery and vein, saphenous nerve and nerve to vastus medialis (both are branches of femoral nerve), genicular branch of posterior division of obturator nerve Femoral Artery  main arterial supply to lower limb  begins at the level of inguinal ligament, as a continuation of external iliac artery  ends at adductor hiatus and after adductor hiatus, it enters popliteal fossa and becomes popliteal artery  descends first through femoral triangle and then through adductor canal  in upper part of femoral triangle, it lies between femoral nerve (lateral to artery) and femoral vein (medial to artery)  in lower part of its course, it lies anterior to femoral vein  branches:  its initial segment gives o small branches that contribute to supply inferior part of anterior abdominal wall and external genitalia (superficial epigastric, superficial circumflex iliac and superficial and deep external pudendal arteries)  muscular branches (supply muscles of anterior and medial compartments of thigh)  profunda femoris (deep femoral) artery  descending genicular artery: small branch that originates from femoral artery close to adductor hiatus and contributes to arterial anastomosis around knee joint Profunda Femoris (Deep Femoral) Artery  largest and most important branch of femoral artery  chief source of blood supply to thigh muscles  originates from femoral artery in upper part of femoral triangle  as it descends, it passes posterior to femoral artery  leaves femoral triangle by passing between pectineus and adductor longus, then it descends posterior to adductor longus, which separates profunda femoris artery from femoral artery  terminates as 4th perforating artery   other branches:  medial and lateral circumflex femoral arteries and arise from profunda femoris near its origin, in femoral triangle (may originate directly from femoral artery)  medial and lateral circumflex femoral arteries pass around upper part of shaft of femur and give o branches to muscles of anterior and medial compartment of thigh, femur, hip joint and knee joint  perforating arteries: there are usually 4 (4th perforating artery is the terminal branch of profunda femoris artery) and perforating arteries pierce adductor brevis and/or adductor magnus (close to their femoral insertion) and reach posterior compartment of thigh and provide chief blood supply to posterior compartment muscles  muscular branches (supply neighboring muscles)  medial and lateral circumflex femoral arteries and arise from profunda femoris near its origin, in femoral triangle (may originate directly from femoral artery)  medial and lateral circumflex femoral arteries pass around upper part of shaft of femur and give o branches to muscles of anterior and medial compartment of thigh, femur, hip joint and knee joint  perforating arteries: there are usually 4 (4th perforating artery is the terminal branch of profunda femoris artery) and perforating arteries pierce adductor brevis and/or adductor magnus (close to their femoral insertion) and reach posterior compartment of thigh and provide chief blood supply to posterior compartment muscles  muscular branches (supply neighboring muscles) Deep Inguinal Lymph Nodes  lie along medial side of upper part of femoral vein  receive lymph from superficial inguinal lymph nodes  also receive lymph from all deep tissues of lower extremity  deep structures located above knee drain directly into deep inguinal lymph nodes  deep structures below knee drain first into popliteal lymph nodes and e erent vessels from popliteal lymph nodes accompany femoral vessels and drain into deep inguinal lymph nodes  e erent vessels from deep inguinal lymph nodes drain into external iliac lymph nodes Femoral Sheath  fascia that lines abdominal walls (endoabdominal fascia) extends into upper thigh to form femoral sheath  femoral sheath surrounds femoral vessels and lymphatics for about 1 inch inferior to inguinal ligament (does not surround femoral nerve) à blends inferiorly with adventitia of femoral vessels  consists of 3 compartments separated by septa:  lateral compartment: contains femoral artery  intermediate compartment: contains femoral vein  medial compartment: it is known as femoral canal and contains lymph vessels and usually one of the deep inguinal lymph nodes  femoral canal is the site of femoral hernias (protrusion of abdominal contents through femoral canal into upper thigh) Femoral Nerve  largest branch of lumbar plexus (formed by fibers from posterior divisions of ventral rami of L2-L4 spinal nerves)  emerges from lateral border of psoas major within abdomen and descends in interval between psoas major and iliacus  enters thigh by passing inferior to inguinal ligament in muscular space (lacuna)  in femoral triangle, it is located lateral to femoral artery, outside femoral sheath  terminates by dividing into multiple branches about 4 cm inferior to inguinal ligament  branches:  muscular branches to iliacus, sartorius, pectineus and 4 heads of quadriceps femoris  anterior cutaneous nerves of thigh (anterior femoral cutaneous nerves): supply skin of anterior surface and part of medial surface of thigh  articular branches to hip and knee joints  saphenous nerve Saphenous nerve  longest branch of femoral nerve   runs inferiorly and medially, first in femoral triangle and then in adductor canal (passes anterior to femoral vessels in adductor canal)  becomes superficial on medial side of knee and descends along medial side of leg with great saphenous vein and passes anterior to medial malleolus and runs along medial border of foot, usually as far as 1st metatarsophalangeal joint (ball of great toe)  supplies skin of medial aspect of leg and along medial border of foot to ball of great toe Obturator Nerve  branch of lumbar plexus (formed by fibers from anterior divisions of ventral rami of L2-L4 spinal nerves)  emerges from medial border of psoas major and runs anteriorly on lateral wall of pelvis with obturator artery and vein and leaves pelvis and enters medial compartment of thigh via obturator canal (upper part of obturator foramen)  within obturator canal, it divides into anterior and posterior branches (divisions)  anterior branch: descends between adductor longus and adductor brevis and supplies adductor longus, adductor brevis and gracilis (occasionally pectineus), hip joint and a small cutaneous area on medial aspect of thigh  posterior branch: pierces obturator externus and descends between adductor brevis and adductor magnus and supplies obturator externus and adductor part of adductor magnus (occasionally adductor brevis) and knee joint