Anterior and Medial Thigh Anatomy PDF

Anterior and Medial Thigh 1 The Thigh 1. Surface Anatomy/Bony Landmarks of the Thigh (more in lab!) a. greater trochanter of the femur h. Lateral supr...

Anterior and Medial Thigh 1 The Thigh 1. Surface Anatomy/Bony Landmarks of the Thigh (more in lab!) a. greater trochanter of the femur h. Lateral supracondylar line b. lesser trochanter of the femur i. Medial supracondylar line c. gluteal tuberosity of the femur j. Adductor tubercle d. linea aspera of the femur k. Medial Epicondyle e. Intertrochanteric crest and l. Lateral epicondyle quadrate tubercle of the femur m. Lateral condyle f. Trochanteric fossa n. Medial condyle g. Intertrochanteric line o. Popliteal surface (Moore, Dalley & Agur, 2010) Section 1 Anterior and Medial Thigh 2 2. Bony Considerations a. Angle of inclination b. Angle of Torsion 3. Organization of the Thigh a. Three compartments: anterior, medial and posterior b. Each compartment has a specific innervation and blood supply Section 1 Anterior and Medial Thigh 3 4. Fascia of the Thigh a. Deep/ Investing fascia (Fascia Lata) i. Attached to iliac crest, dorsal sacrum, sacrotuberous ligament, inferior ramus, body, and superior ramus of the pubic bone ii. Thickening of fascia lata along the lateral thigh is the iliotibial (IT) tract iii. Gluteus maximus and Tensor fascia lata insert into the IT tract  provide lateral stability for pelvis iv. Inferiorly the fascia lata blends with the crural fascia of the leg b. Notes on fascia of the thigh i. The Iliotibial tract/ band is a thickening of the fascia lata (it is not separate from the fascia that wraps the thigh) Section 1 Anterior and Medial Thigh 4 5. Anterior Thigh a. Overview i. The six muscles of the anterior compartment are primarily extensors of the knee and flexors of the hip ii. All muscles of the anterior thigh are innervated by branches of the femoral nerve iii. Blood supply is from the femoral artery Section 2 Anterior and Medial Thigh 5 b. Muscles of the Anterior Thigh Muscle Origin Insertion Nerve Action Adducts and Femoral flexes thigh Pectineal line of nerve (L2,3) Pectineus Superior ramus of pubis assists with femur, (may receive medial rotation obturator n) of thigh Tendon of psoas Iliac crest, iliac fossa, ala of Act to flex thigh major lesser Femoral n Iliacus sacrum, and anterior at hip and trochanter and L2,3 sacroiliac ligaments stabilize joint femur just distal to it hip flexion Sides of T12-L5 vertebrae Anterior lat flexion of bodies and discs between Lesser trochanter of rami of lumbar Psoas major them, transverse processes femur lumbar vertebrae of all lumbar vertebra nerves L1,2,3 extend lumber vertebrae Pectineal line, Anterior Acts on lumbar Sides of T12-L1 vertebrae iliopectineal rami of Psoas minor spine (weak and intervertebral discs eminence via lumbar trunk flexor) iliopectineal arch nerves L1, Flexs, abducts, Superior part of and laterally ASIS and superior part of Femoral n Sartorius medial surface of rotates thighat notch inferior to it L2,3 tibia hip, flexes leg at knee joint Muscle Origin Insertion Nerve Action Rectus AIIS and ilium superior to Via common Femoris acetabulum tendinous and Extend leg at greater trochanter and independent Vastus knee joint rectus lateral lip of linea aspera of attachments to base Lateralis femoris also femur of patella, indirectly Femoral steadies hip intertrochanteric line and via patellar ligament nerve L2.3.4 Vastus joint and helps medial lip of linea aspera of to tibal tub, medial Medialis iliopsoas flex femur and lateral vasti also thigh Vastus anterior and lateral surfaces attach to tibia and Intermedius of shaft of femur patella aponeuroses Section 2 Anterior and Medial Thigh 6 c. Specific Considerations for the Anterior Thigh i. Iliopsoas 1. Arises from two muscles (iliacus and psoas major) 2. Iliacus innervated by femoral nerve, psoas innervated by ventral rami of L1-L3 3. Note that psoas minor does NOT cross the hip joint 4. Psoas major is the primary hip flexor past 90° of flexion a. Considering the origin of psoas major, how can psoas major affect the spine in a closed chain? b. How might a tight psoas major affect posture? ii. Tensor Fascia Lata 1. Found in anterior thigh, but is functionally grouped with the gluteal muscles. What is its innervation? iii. Sartorious 1. Longest muscle in the body 2. Tendon inserts at pes anserinus with semitendinosus and gracilis (bursa between the tendons, can become inflamed) 3. How can you remember all of the actions? iv. Quadriceps 1. Insert via a common tendon that splits to insert into the superior aspect of the patella, then rejoin to insert into the tibial tuberosity 2. Patella helps to align the forces of the four muscles and improves the lever arm 3. With petallar fractures, the superior fragment may be displaced superiorly due to the force of the muscles v. Articularis Genu 1. Arises from the the inferior fibers of the vastus intermedius muscle. 2. Inserts into the superior part of a reflection of the knee joint synovium called the suprapatellar bursa. 3. Action: raises the bursa superiorly during extension of the knee to prevent the synovium from getting caught in the knee. Section 2 Anterior and Medial Thigh 7 vi. Femoral Nerve 1. Innervates muscles of the anterior thigh 2. Cutaneous innervation to anterior, medial and lateral thigh 3. Innervation to hip and knee joint a. Consider possible pain referral patterns for these joints based on structures innervated by the femoral nerve Section 2 Anterior and Medial Thigh 8 6. Femoral Triangle a. Boundaries of Femoral Triangle i. Lateral: the medial edge of sartorius ii. Medial: the lateral edge of adductor longus iii. Superiorly- inguinal ligament iv. Apex = where Sartorius crosses adductor longus v. Floor: iliopsoas, pectineus. vi. Roof: fascia lata- because it is perforated by vessels and nerves it is called the cribriform fascia. (Moore, Dalley & Agur, 2016) Section 3 Anterior and Medial Thigh 9 b. Contents of Femoral Triangle i. Femoral nerve and its branches ii. Femoral Sheath Encasing: 1. Femoral artery and its branches (key branches listed) a. The profunda femora artery. i. the medial and lateral circumflex femoral arteries  blood supply to hip. 2. Femoral vein (and tributaries including great saphenous vein) 3. Femoral Canal a. The canal contains loose connective tissue and transmits lymphatics from the LE to the trunk (may contain a deep lymph node) b. The femoral ring is the superior opening of the femoral canal at the inguinal ligament i. Occasionally abdominals contents can herniate through the femoral ring  Femoral Hernia (Moore, Dalley & Agur, 2016) 7. Adductor Canal (Subsartorial Canal) a. A tunnel formed between adductor longus/magnus (medially), vastu medialis (laterally) and sartorious (anteriorly) b. Contains femoral artery and vein, terminal portions of femoral nerve (nerve to VM and saphenous nerve) c. In the distal thigh, the artery and vein pass through the adductor hiatus (opening in adductor magnus) to pass posteriorly to the popliteal fossa d. The saphenous nerve continues medially to provide cutaneous innervation to the medial leg Section 3 Anterior and Medial Thigh 10 8. Medial Thigh a. Overview i. Primarily innervated by the obturator nerve (except part of adductor magnus and pectineus) ii. Most have origins on the pubic body and/or rami and insert on the posterior femur Section 4 Anterior and Medial Thigh 11 b. Muscles of the Medial Thigh Muscle Origin Insertion Nerve Action Adducts and Femoral nerve (L2,3) flexes thigh Superior ramus of Pectineal line of May receive a Pectineus assists medial pubis femur, branch of obturator rotation of nerve thigh Body of pubis Middle 1/3 of Obturator nerve Adductor inferior to pubic linea aspera of branch of anterior Adduct thigh longus crest femur division, L2,3,4 Pectineal line and Obturator nerve Adducts thigh, Adductor Body and inferior proximal part of branch of anterior to some extent brevis ramus of pubis linea aspera of division, L2,3,4 flexes it femur Adductor: gluteal Adductor: obturator Adductor: inferior tub, linea aspera, nerve (L2,3,4) Adducts thigh ramus of pubis, medial branches of Adductor: Adductor ramus of ischium supracondylar line posterior division flexes thigh magnus Hamstring: ischial Hamstring: Hamstrings: tibial Hamstrings: tub adductor tubercle part of sciatic nerve extends thigh of femur L4 Adducts thigh, Superior part of Body and inferior Obturator nerve flexes leg, helps Gracilis medial surface of ramus of pubis L2,3 medially rotate tibia leg Laterally Margins of rotates thigh, Obturator obturator foramen Trochanteric fossa Obturator nerve steadies head externus and obturator of femur L3,4 of femur in membrane acetabulum c. Clinical Considerations for medial thigh i. Gracilis is the thinnest and weakest of the adductor muscles. It also is the only adductor to cross the knee. It works with the other “pes anserinus” muscles to provide medial stability to the extended knee (similar role to IT tract on lateral aspect of the knee) Section 4 Anterior and Medial Thigh 12 d. Blood Supply to Anterior and Medial Thigh i. Femoral Artery 1. Continuation of external iliac as it passes under inguinal ligament 2. Serves the anterior compartment 3. Travels in adductor/subsartorial canal  then passes through adductor hiatus to become Popliteal Artery ii. Medial and Lateral Femoral Circumflex Arteries 1. Branch off profunda femoral in the femoral triangle 2. Medial serves femoral neck and head and joins with gluteal arteries 3. Lateral a. Ascending branch serves anterior gluteal region b. Descending branch wraps around femur and anastomoses at the knee iii. Profunda Femoris Artery 1. Branches off femoral in the femoral triangle 2. Muscular branches to adductors 3. Four perforating branches pierce adductor magnus to supply the posterior thigh iv. Obturator Artery (branch of internal iliac) 1. Travels in adductor compartment Section 5 Anterior and Medial Thigh 13 e. Innervation of the Anterior and Medial Thigh i. Femoral Nerve (from the lumbar plexus) 1. Branches out into many small branches in the femoral triangle 2. Saphenous nerve is a sensory branch that continues in adductor canal to provide sensory innervation to medial leg ii. Obturator Nerve (from lumbar plexus) 1. Descends through the pelvis, pierces obturator membrane and obturator externus muscle 2. Divides into anterior and posterior branches that course on the anterior and posterior surfaces of the adductor brevis. Femoral Nerve Obturator Nerve Section 5 Anterior and Medial Thigh 14 9. Overview in Cross Section a. Try to get oriented to the muscle organization in cross section b. Appreciate how vastus lateralis wraps around the lateral femur to the posterior c. Examine the organization of the neurovascular supply with respect the muslces/compartments d. Identify the medial, anterior and posterior compartments (Moore, Dalley & Agur, 2010) Section 6 Anterior and Medial Thigh 15 10. Pes Anserinus a. Superior medial tibia: common insertion of sartorious, gracilis and semitendinosus b. Provides medial stability to the knee thorugh tension in the three muscles Section 6