Thigh Anatomy PDF

XY2141. ANATOMY. THIGH REGION Dr Viktoriia Yerokhina, Lecturer in Medical Sciences [email protected]  LEARNING OUTCOMES ANAT.34 - Thigh ANAT.34.01 - Name and describe the key bones (and bony features) of the femur. ANAT.34.02 - Nam...

XY2141. ANATOMY. THIGH REGION Dr Viktoriia Yerokhina, Lecturer in Medical Sciences [email protected]  LEARNING OUTCOMES ANAT.34 - Thigh ANAT.34.01 - Name and describe the key bones (and bony features) of the femur. ANAT.34.02 - Name and describe the major joints associated with the thigh and identify their actions (hip and knee). ANAT.34.03 - Review the compartments of the thigh, the muscles within each compartment and describe their functions. ANAT.34.04 - Name and describe the course and distribution of the main vascular and neurological structures of the thigh. ANAT.34.05 - Define the boundaries and contents of the femoral triangle and popliteal fossa. ANAT.34.06 - Compare and contrast the ligaments and menisci of the knee and review their function(s) in knee stability and movement ANAT.34.07 - Apply anatomical knowledge to clinical correlations of the thigh hip, and knee region, as discussed (E.g. Coxa vara, Coxa valga, hip dislocation, Perthes disease, unhappy triad).  THIGH Thigh is the part of the lower limb between the hip and knee joints.  FASCIA OF THE GLUTEAL REGION AND THIGH 1. Gluteal fascia (fascia glutea) – covers the gluteus maximus and gluteus medius – attaches proximally to the iliac crest medially to the sacrum, distally continues as the fascia lata.  FASCIA OF THE GLUTEAL REGION AND THIGH 2. Fascia lata (fascia lata femoris) - deep fascia of the thigh is very strong and envelops the thigh like a sleeve. It is called fascia lata because it encloses a wide area of the thigh (Latin Latus: broad) Attaches proximally to the iliac crest and ingiunal ligament, continues dorsally as the gluteal fascia Attaches distally to the epicondyles of the femur, base of the patella and head of the fibula.  FASCIA OF THE GLUTEAL REGION AND THIGH Parts of the fascia lata: 2.1 Iliotibial tract (tractus iliotibialis) – thickened lateral band of the fascia lata – attaches to the tuberosity for the iliotibial tract (tubercle of Gerdy) 2.2 Lateral, medial and anteromedial femoral intermuscular septa – create the 3 compartments of the thigh (anterior, posterior and medial).  MUSCLES OF THE THIGH Muscles of the thigh are organised into three groups: anterior, medial posterior Quadriceps femoris forms the anterior group and is the only extensor of the leg.  MUSCLES OF THE THIGH 1. Anterior group 1.1 Sartorius (m. sartorius) 1.2 Quadriceps femoris (m. quadriceps femoris) 2. Medial group 2.1 Pectineus (m. pectineus) 2.2 Adductor longus (m. adductor longus) 2.3 Gracilis (m. gracilis) 2.4 Adductor brevis (m. adductor brevis) 2.5 Adductor magnus (m. adductor magnus) 2.6 Obturator externus (m. obturatorius externus)  MUSCLES OF THE THIGH 3. Posterior group 3.1 Biceps femoris (m. biceps femoris) 3.2 Semitendinosus (m. semitendinosus) 3.3 Semimembranosus (m. semimembranosus)  MUSCLES OF THE THIGH – ANTERIOR GROUP Covers the entire anterior surface of the thigh and have a common innervation from the femoral nerve. Quadriceps femoris is comprised of four heads: rectus femoris, vastus lateralis, vastus intermedius, vastus medialis. Rectus femoris can be further divided into two heads: straight head, reflected head. Rectus femoris is the only head of the quariceps femoris that acts not only at the knee joint, but also at the hip joint.  MUSCLES OF THE THIGH – ANTERIOR GROUP Quadriceps femoris (musculus quadriceps femoris) Origin 1. Rectus femoris (m. rectus femoris): 1.1 Straight head (caput rectum): ilium – anterior inferior iliac spine 1.2 Reflected head (caput reflexum): ilium – supra- acetabular groove 2. Vastus lateralis femur – linea aspera, femur – intertrochanteric line (proximal part) 3. Vastus intermedius femur – anterior and lateral surfaces 4. Vastus medialis femur – linea aspera, femur – intertrochanteric line (distal part) I: tibial tuberosity – via the patellar ligament  MUSCLES OF THE THIGH – ANTERIOR GROUP Quadriceps femoris (m. quadriceps femoris)  MUSCLES OF THE THIGH – ANTERIOR GROUP F of quadriceps femoris: extension of the leg, control of flexion of the leg (muscle often works in a state of eccentric contraction), flexion of the thigh (rectus femoris only). N: femoral nerve (L2–L4). MUSCLES OF THE THIGH – ANTERIOR GROUP  MUSCLES OF THE THIGH – ANTERIOR GROUP Sartorius derives from the Latin word sartor, meaning tailor, and it is occasionally referred to as the tailor's muscle. This name was chosen in reference to the cross-legged position in which tailors once sat.  MUSCLES OF THE THIGH – ANTERIOR GROUP Sartorius O: ilium – anterior superior iliac spine I: tibia – medial condyle (via the pes anserinus major) F: flexion, abduction and external rotation of the thigh, flexion of the leg, internal rotation of the flexed leg N: femoral nerve (L2–L3)  MUSCLES OF THE THIGH – MEDIAL GROUP - ADDUCTORS Muscles in the medial group are adductors. Common innervation of the medial group: obturator nerve. Two diploneural muscles belong to this group: pectineus and adductor magnus. Adductor magnus can be divided into two unnamed parts (adductor part and extensor part), each with its own innervation.  MUSCLES OF THE THIGH – MEDIAL GROUP - ADDUCTORS Pectineus (m. pectineus) O: pubis – pecten pubis I: femur – pectineal line F: adduction, flexion and external rotation of the thigh N: femoral nerve (L2–L3), obturator nerve (L2–L3) Adductor longus (m. adductor longus) O: pubis – in between the pubic tubercle and pubic symphysis I: femur – linea aspera (middle 1/3 of the medial lip) F: adduction, flexion and external rotation of the thigh N: obturator nerve (L2–L3). MUSCLES OF THE THIGH – MEDIAL GROUP - ADDUCTORS Gracilis (m. gracilis) O: pubis – body and inferior pubic ramus I: tibia – medial condyle (via the pes anserinus major) F: adduction of the thigh, flexion of the leg, internal rotation of the flexed leg N: obturator nerve (L2–L4) Adductor brevis (m. adductor brevis) O: pubis – inferior pubic ramus I: femur – linea aspera (proximal 1/3 of the medial lip) F: adduction, flexion and external rotation of the thigh N: obturator nerve (L2–L4)  MUSCLES OF THE THIGH – MEDIAL GROUP - ADDUCTORS Adductor magnus (m. adductor magnus) 1. Adductor part O: pubis – inferior pubic ramus I: femur – linea aspera (medial lip) F: adduction and flexion of the thigh N: obturator nerve (L2–L4) 2. Extensor part O: ischium – ramus and ischial tuberosity I: femur (medial condyle) – adductor tubercle F: extension and internal rotation of the thigh N: sciatic nerve (L2–L4), obturator nerve (L2–L4).  MUSCLES OF THE THIGH – MEDIAL GROUP - ADDUCTORS Obturator externus (m. obturatorius externus) O: external surface of the obturator membrane, obturator foramen (bony margins) Course of fibers: run dorsally to the neck of the femur I: femur – trochanteric fossa F: external rotation of the thigh, accessory flexion of the thigh N: obturator nerve (L3–L4)  MUSCLES OF THE THIGH – POSTERIOR GROUP Posterior group of the thigh muscles are extensors of the hip joint and flexors of the knee joint. Muscles of posterior compartment of the thigh are called hamstring muscles. This group consists of three muscles that have a common innervation from the sciatic nerve. Biceps femoris has a long and short head. If the sciatic nerve divides proximally (a high division of the sciatic nerve), the biceps femoris is a diploneural muscle, innervated by both the tibial and fibular nerves.  MUSCLES OF THE THIGH – POSTERIOR GROUP Biceps femoris (m. biceps femoris) Origin: 1. Long head (caput longum): ischial tuberosity 2. Short head (caput breve): femur – linea aspera (middle 1/3 of the lateral lip) I: fibula – head of fibula F: flexion of the leg, external rotation of the flexed leg, extension and accessory external rotation of the thigh (the long head only) N: sciatic nerve (L5–S1, variably L4–S2) 1. Long head: tibial nerve 2. Short head: common fibular nerve  MUSCLES OF THE THIGH – POSTERIOR GROUP Semitendinosus (m. semitendinosus) O: ischial tuberosity I: tibia – medial condyle F: flexion of the leg, internal rotation of the flexed leg, extension and internal rotation of the thigh, N: sciatic nerve – tibial nerve (L4–S1) Semimembranosus (m. semimembranosus) O: ischial tuberosity I: tibia – medial condyle (2 insertions), femur – lateral condyle F: flexion of the leg, internal rotation of the flexed leg, extension and internal rotation of the thigh N: sciatic nerve – tibial nerve (L4–S1)  FEMORAL ARTERY – ARTERIA FEMORALIS Continuation of the external iliac artery after passing through the vascular space (lacuna vasorum). It enters the femoral triangle on the anterior side of the thigh where it gives off branches that supply the muscles of the thigh. It passes between the two insertions of the adductor magnus and continues to the popliteal fossa as the popliteal artery. Popliteal artery supplies the knee joint and adjacent muscles and continues as the anterior and posterior tibial arteries to the leg.  FEMORAL ARTERY – ARTERIA FEMORALIS Branches: 1. Superficial epigastric artery (a. epigastrica superficialis) – passes in the subcutaneous tissue of the anterior abdominal wall 2. Superficial circumflexiliac artery (a. circumflexa ilium superficialis) – passes in subcutaneous tissue along the inguinal canal to the anterior superior iliac spine 3. External pudendal arteries (aa. pudendae externae) - supply the anterior part of the scrotum/labia majora as the anterior scrotal/labial branches.  FEMORAL ARTERY – ARTERIA FEMORALIS 4. Profunda femoris artery / deep artery of thigh (arteria profunda femoris) – arises from the proximal part of the femoral atery – its branches supply the posterior side of the thigh 4.1 Medial circumflex femoral artery (a. circumflexa femoris medialis) – supplies the sacroiliac joint, adductors and flexors of the thigh 4.2 Lateral circumflex femoral artery (a. circumflexa femoris lateralis) – supplies the quadriceps femoris 4.3 Perforating arteries (arteriae perforantes) – 3 branches, which travel to the posterior side of the thigh to supply the adductors and flexors. FEMORAL ARTERY – ARTERIA FEMORALIS 5. Descending genicular artery (arteria genus descendens) – supplies the anterior thigh muscles and knee joint, passes through the adductor canal. FEMORAL ARTERY – ARTERIA FEMORALIS  VEINS OF THE THIGH 1. Popliteal vein (vena poplitea) – arises from the confluence of the anterior and posterior tibial veins – located in the popliteal fossa and passes through the adductor hiatus to the adductor canal 2. Femoral vein (v. femoralis) – courses medially to the femoral artery and empties into the common femoral vein at the femoral triangle 3. Deep vein of thigh (v. profunda femoris) – collects blood from the interior and posterior surface of the thigh 4. Common femoral vein (v. femoralis communis) – arises at the junction of the femoral vein with the deep vein of the thigh 4.1 Great saphenous vein (v. saphena magna). VEINS OF THE LEG  SCIATIC NERVE (FROM SACRAL PLEXUS) 5. Sciatic nerve (n. ischiadicus) (from sacral plexus) – L5–S2 with contributions from L4 and S3 Course: passes through the infrapiriform foramen between the muscles of the posterior thigh then descends distally towards the popliteal fossa Branches and structures innervated – splits into two main branches: tibial nerve and common fibular nerve 5.1 Muscular branches (rami musculares) – innervates the biceps femoris, semitendinosus, semimembranosus and part of the adductor magnus 5.2 Articular branches (rami articulares) – partial somatosensory innervation of the hip joint.  FEMORAL TRIANGLE - TRIGONUM FEMORALE Triangular depression on the front of the upper one-third of the thigh below the inguinal ligament. Its apex is directed downward.  FEMORAL TRIANGLE - TRIGONUM FEMORALE Boundaries: Lateral: medial border of sartorius. Medial: medial border of adductor longus. Base: inguinal ligament. Apex: it is formed by the meeting point of the medial borders of adductor longs and sartorius.  FEMORAL TRIANGLE - TRIGONUM FEMORALE Floor: it is gutter-shaped and muscular. From lateral to medial side it is formed by the following muscles: 1. Iliacus. 2. Psoas major (tendon). 3. Pectineus. 4. Adductor longus. Roof: formed by the fascia lata having saphenous opening.  CONTENT OF FEMORAL TRIANGLE 1. Femoral artery and its branches 2. Femoral vein and its tributaries 3. Femoral nerve 4. Deep inguinal lymph nodes 5. Lateral cutaneous nerve of the thigh In addition to above structures, it also contains: 1. Femoral branch of the genitofemoral nerve (F) 2. Fibrofatty tissue. To remember the femoral triangle contents, think LaMe NAVEL: (from lateral to medial) femoral Nerve, Artery, Vein, Empty space Boundaries and contents of the femoral triangle (femoral canal → femoral hernia), Lymphatics (F = femoral branch of the genitofemoral nerve).  FEMORAL SHEATH A funnel-shaped fascial sheath enclosing the upper 3–4 cm of the femoral vessels. Femoral sheath is divided into three compartments by two septa: 1. Lateral compartment contains the femoral artery and the femoral branch of the genitofemoral nerve. 2. Intermediate compartment contains the femoral vein. 3. Medial compartment is small and known as the femoral canal.  CLINICAL CORRELATION – FEMORAL HERNIAS A femoral hernia is an uncommon type of inguinal hernia, in which intra- abdominal contents (e.g., intraperitoneal fat, mesentery, bowels) herniate into the femoral canal through the femoral ring. Risk factors: old age, female sex, obesity, and previous hernia repair. Due to the increased width of the female pelvis, and therefore larger vascular lacuna, femoral hernia occurs predominantly in women.  Femoral triangle and adductor canal. (The red arrow indicates the passage of femoral artery.) Distally, femoral triangle continue as the adductor canal, which leads to the popliteal fossa.  ADDUCTOR CANAL – CANALIS ADDUCTORIUS (SUBSARTORIAL CANAL/HUNTER’S CANAL ) Boundaries 1. Medially: adductor longus 2. Laterally: vastus medialis 3. Ventrally: vasto-adductor membrane 4. Dorsally: adductor magnus Content 5. Femoral artery and vein 6. Saphenous nerve  POPLITEAL FOSSA – FOSSA POPLITEA Boundaries 1. Medioproximally: semimembranosus and semitendinosus 2. Lateroproximally: biceps femoris 3. Mediodistally: gastrocnemius – medial head 4. Laterodistally: gastrocnemius – lateral head 5. Bottom (ventrally): popliteus Content 6. Sciatic nerve 6.1 Tibial nerve 6.2 Common fibular nerve 7. Popliteal artery and its branches 8. Popliteal vein and its tributary veins 9. Popliteal lymph nodes POPLITEAL FOSSA – FOSSA POPLITEA SURFACE ANATOMY OF THIGH AND KNEE REFERENCES