Anterior and Medial Thigh Anatomy PDF

Anterior and Medial Thigh Mange Manyama, M.D., Ph.D. I do not have financial interest in commercial products or services related to the subject of this lecture PollEv.com/ manyama837 O...

Anterior and Medial Thigh Mange Manyama, M.D., Ph.D. I do not have financial interest in commercial products or services related to the subject of this lecture PollEv.com/ manyama837 October 21, 2024  Suggested readings: Essential Clinical Anatomy - Moore’s 6th Ed. P. 433-441 Bones of lower limb Fascia of the thigh Anterior and Medial thigh muscles Neurovascular structures and relantionship in anteromedial thigh Femoral fractures Paralysis of Quadriceps muscles Femoral hernia Saphenous cutdown  Learning objectives Bony landmarks on the Hip bone and Femur Muscles of anterior and medial compartments of thigh: attachments, nerve supply and functions. Blood vessels on the anterior & medial side of the thigh. Femoral and obturator nerves and their distributions. Anatomical spaces in the anterior and medial sides of thigh. Associated clinical application of the structures in the lower limb.  Overview of the Upper and Lower Limbs Cubital fossa Popliteal fossa Anatomical position The lower limbs are similar in structure in many respects to the upper limbs During the 8th week of development The upper limb rotates laterally by 90 degrees, so that the palm faces anteriorly. As a result, the future flexor muscles lie on the anterior, and the extensor muscles lie on the posterior aspect of the upper limb. In contrast, the lower limb undergoes a 90-degree medial rotation; bringing the big toe to the medial side of the foot. As result, the flexor muscles lie on the posterior, and extensor muscles lie on the anterior aspect of the lower limb  The Hip bone The hip bone is formed by the fusion of the ilium, ischium, and pubis at the acetabulum Some of the bony landmarks that provides attachments for the muscles on the anterior, medial and posterior thigh: –Anterior superior iliac spine – Sartorius muscle –Anterior inferior iliac spine – Rectus femoris muscle –Iliac fossa – Iliacus muscle –Ischial tuberosity – Hamstring muscles  The Femur The fovea on the head is for the attachment of the ligament of the head of the femur. In early life, the ligament gives passage to an artery (branch of obturator) supplying the of the head of the femur The lesser trochanter provides distal attachment for the iliopsoas tendon. The greater trochanter provide attachments to the abductors and medial rotators of the hip Linea aspera (rough line) - provides attachment for some of the adductor muscles of the thigh The site where the neck and shaft join is indicated by the Intertrochanteric line anteriorly and intertrochanteric crest posteriorly  Superficial neurovascular structures of the lower limb Great saphenous vein cutdown The lateral and anterior femoral cutaneous nerves are within the superficial fascia The great saphenous vein (usually accompanied by the saphenous nerve in the leg) drains the dorsal venous arch of the foot, passes anterior to the medial malleolus, Joins the femoral vein by passing through the saphenous opening. Clinical: Great saphenous vein is a popular site for venous access by means of venous cutdown. The vein is sometimes also used for coronary arterial bypasses surgery Deep fascia of thigh (fascia lata) has a gap below the inguinal ligament known as the saphenous opening Iliotibial tract (IT band) - a thickened lateral portion of fascia lata; attaches distally to anterolateral tubercle of tibia. It encloses & anchors the tensor fasciae latae muscle and serves as a distal attachment for most of Gluteus maximus muscle.  Muscles of the Thigh The thigh muscles are organized into three compartments by intermuscular septa: –Anterior (knee extensors) – innervated by femoral nerve –Medial (hip adductors) – innervated by obturator nerve –Posterior (knee flexors) – innervated by tibial and common peroneal nerves (branches of sciatic)  Anterior Thigh Muscles The sartorius bring the lower limbs into the cross-legged sitting position (tailor’s muscle). It flexes, abducts, and laterally rotates thigh at hip joint; and flexes leg at knee joint. It’s proximal attachment is on the ASIS. The quadriceps femoris consists of the rectus femoris, vastus lateralis, intermedius, and medialis muscles. Tendons of these muscles unite to form the quadriceps tendon that inserts onto the patella. Continuation of the quadriceps tendon from the patella to the tibial tuberosity is known as Patellar ligament. Quadriceps femoris is main extensor of the leg. The pectineus muscle is innervated by both femoral and obturator nerves  Psoas major muscle abscess Psoas abscess: A retroperitoneal pus-forming infection in the abdomen or greater pelvis, may result in the formation of a psoas abscess. When the abscess passes between the psoas and its fascia to the inguinal and proximal thigh regions, severe pain may be referred to the hip, thigh, or knee joint.  Medial thigh muscles Comprises the adductor longus, adductor brevis, adductor magnus, gracilis, and obturator Externus The Gracilis muscle, together with the sartorius and semitendinosus have a common tendinous insertion, the pes anserinus (goose’s foot), into the superior part of the medial surface of the tibia. The adductor magnus has an adductor part (innervated by obturator n.) & a hamstring part (innervated by tibial n.). Adductor hiatus is a gap between the adductor and the hamstrings attachments of the adductor magnus. Transmits the femoral artery and vein from the adductor canal in the thigh to the popliteal fossa posterior to the knee. Femoral triangle and Femoral sheath Boundaries: –Medial: Lateral border of the Adductor longus muscle –Lateral: Sartorius muscle –Superior (Base): Inguinal ligament Contents of the femoral triangle, from lateral to medial, are: –Femoral nerve and its terminal branches –Femoral artery and vein, and Femoral canal (which contains deep inguinal lymph nodes). The proximal parts of the femoral artery, vein and canal are surrounded by the Femoral sheath. Femoral sheath - is a funnel-shaped fascial tube formed by an inferior prolongation of transversalis and iliopsoas fascia from the abdomen.  Femoral canal Femoral canal - medial compartment of the femoral sheath, which contains lymph vessels and nodes Its upper end that opens into the abdomen is called femoral ring. Boundaries of the femoral ring: – Anterior: Inguinal ligament – Posterior: Superior ramus of the pubis covered by the pectineal ligament – Medial: Lacunar ligament – Lateral - Femoral septum between the femoral canal and the femoral vein Femoral hernia - protrusion of abdominal viscera through the femoral ring into the femoral canal. More common in females.  The inguinal hernia emerges above and medial to the pubic tubercle, while the femoral hernia lies below and lateral to it. The femoral hernia also passes posterior (deep) to the inguinal ligament. When the aberrant/accessory obturator artery (from the external iliac or inferior epigastric artery) is present, it usually runs close to or across the femoral ring to reach the obturator foramen and could be closely related to the neck of a femoral hernia. During endoscopic repair of femoral hernias care must betaken to protect this common arterial variant.  Adductor Canal The Adductor Canal (subsartorial canal or Hunter canal) - an intermuscular passageway deep to the sartorius by which the major neurovascular bundle of the thigh traverses the middle third of the thigh Boundaries – Laterally (and anteriorly) by the vastus medialis. – Posteriorly by the adductors longus and magnus. – Medially by the sartorius, Contents include the femoral artery, femoral vein, saphenous nerve and nerve to vastus medialis  Nerves in the anteromedial thigh Femoral nerve – Posterior division of the ventral rami of L2-L4 – Innervates anterior thigh muscles (Sartorius, Pectineus, Quadriceps femoris, Iliacus) – Saphenous nerve - a terminal branch of femoral nerve; innervates the skin on the anteromedial aspects of the knee, leg, and foot. Obturator nerve – Anterior division of the ventral rami of L2-L4 – The obturator nerve passes through the obturator canal and divides into anterior and posterior branches. – Anterior branch passes anterior to adductor brevis to innervate adductor longus, adductor brevis and gracilis muscles. – Posterior branch passes posterior to the adductor brevis to supply the obturator externus, and adductor magnus (adductor part). Deep arteries and nerves of the thigh (anterior view)  Femoral vessels Femoral artery - continuation of the external iliac artery distal to the inguinal ligament, provides most of blood supply to the lower limb through its branches. –Deep artery of the thigh (Profunda femoris artery) – a branch of the femoral artery. Branches include: Medial and Lateral circumflex femoral arteries, and Four Perforating arteries. After passing through the adductor hiatus, the femoral artery becomes the popliteal artery. Femoral vein - Continuation of the popliteal vein proximal to the adductor hiatus. Cruciate anastomosis – Anastomosis posterior to the femur involving the medial and lateral circumflex femoral arteries, inferior gluteal artery, and the first perforating artery. Provides the important connection between the internal iliac and the femoral arteries – The medial circumflex femoral artery provides most of the blood supply to the head and neck of the femur through its posterior retinacular arteries.  Femoral neck fractures and avascular necrosis of the head of the femur Fractures of the femoral neck often disrupt the blood supply to the head of the femur (supplied by the medial circumflex femoral artery through the retinacular branches) The retinacular arteries arising from this artery are often torn when the femoral neck is fractured. The artery to the ligament of the femoral head artery is frequently inadequate for maintaining the femoral head; consequently, the fragment may undergo avascular necrosis. Obturator artery: – A branch of anterior division of Internal Iliac artery. Helps the profunda femoris artery supply the adductor muscles In ~20% of people, the obturator artery may arise from the external iliac artery and in such a case it is known as aberrant/accessory obturator artery. This artery runs close to or across the femoral ring to reach the obturator foramen and could be closely related to the neck of a femoral hernia EIA – External iliac artery IIA - Internal iliac artery OA – Obturator artery (aberrant) SG – Superior gluteal artery IG – Inferior gluteal artery IP – Internal pudendal artery SV – Superior vesical artery