lower limb- thigh and gluteal region

Question 1

what are the three compartments of the thigh? describe them.

Answer 1

• anterior/extensor of knee/flexor of hip (femoral innervation). includes the femur.
• medial/adductor (obturator nerve)
• posterior/flexor of knee/extensor of hip (tibial portion of sciatic nerve)
• the gluteal compartment contains the abductors.

Question 2

name the anterior thigh muscles

Answer 2

• pectineus
• iliopsoas
• sartorius
• quadriceps femoris

Question 3

describe the location, attachments, innervation and action of pectineus

Answer 3

• flat, quadrangular shaped muscle in anterior superomedial thigh
• adducts and flexes the thigh and assists in medial rotation
• proximal attachment is to the superior ramus of pubis, distal attachment is to the pectineal line of femur just inferior to lesser trochanter
• innervation is mostly from the femoral nerve.

Question 4

describe the location, attachments, innervation and action of iliopsoas

Answer 4

• lies in the posterior wall of abdomen and greater pelvis
• acts as the most powerful flexor of the hip. also has a stabilising action
• is divided into psoas major, psoas minor and iliacus
• psoas major attaches proximally to sides of T12-L5 vertebrae (and discs and transverse processes). distally attaches to the lesser trochanter of femur. innervation is anterior rami of L1-3)
• psoas minor attaches proximally to sides of T12-L1, attaches distally to pectineal line and iliopectineal eminence. nerve supply is anterior rami of L1-2
• iliacus attaches proximally to the iliac crest, diliac fossa and ala of sacrum. distally attaches to tendon on psoas major, lesser trochanter and femur distal to that. innervation is femoral nerve (L2-3)

Question 5

describe the location, attachments, innervation and action of sartorius

Answer 5

• passes obliquely across the superoanterior thigh
• acts to flex hip joint, also weakly flexes knee, weakly abducts thigh and laterally rotates it (think leg crossing)
• proximal attachment is ASIS and notch inferior to it, distal attachment is to superior part of medial surface of tibia
• innervation is femoral nerve (L2-3)

Question 6

describe the location, attachments, innervation and action of the various parts of quadriceps femoris

Answer 6

• forms the main bulk of the anterior thigh. has four parts: rectus femoris, vastus lateralis, vastus intermedius, vast us medialis
• major action is extension of the knee. rectus femoris also acts to flex the hip
• distal attachment of all four segments is the quadriceps tendon in which the patella is embedded. the extension of this tendon is the patella ligament which attaches to the tibial tuberosity. note that the medial and lateral vasti also attach independently to the patella via aponeuroses. these help to stabilise the knee
• innervation to all segments is demoral (L2-4)
• proximal attach of the rectus femoris is AIIS
• proximal attach of the vastus lateralis is greater trochanter and lateral lip of linea aspera
• proximal attach of the vastus medialis is intertrochanteric line and medial lip of linea aspera
• proximal attach of vastus intermedialis is anterior and lateral surfaces of shaft of femur

Question 7

what is a psoas abcess?

Answer 7

• abscess arising in the abdomen from the sides of the T12-L5 intervertebral discs/vertebrae/transverse processes
• can occur in assoc with tuberculosis or complicating inflammatory bowel disease
• pain may be referred to hip, thigh or knee
• sometimes may be palpated in the inguinal region

Question 8

name the five medial thigh muscles

Answer 8

• adductor longus, adductor brevis, adductor magnus, gracilis and obturator externus

Question 9

describe the location, action, innervation and attachment of the adductor longus

Answer 9

• large, fan shaped, most anteriorly placed of the adductor group
• acts to adduct thigh
• innervation is obturator (L2-4)
• proximal attachment is body of pubis inferior to pubic crest
• distal attachment is middle third of linea aspera of femur

Question 10

describe the location, action, innervation and attachment of the adductor brevis

Answer 10

• short adductor, lies deep to pectineus and adductor longus
• action is adduction of thigh
• innervation is obturator (L2-4)
• proximal attachment is body and inferior ramus of pubis
• distal attachment is pectineal line and proximal part of linea aspera

Question 11

describe the location, action, innervation and attachment of adductor magnus

Answer 11

• largest, most powerful and most posterior of the adductors. has and adductor part and a hamstring part.
• has an aponeurotic distal attachment along the entire length of the linea aspera of the femur, extending inferiorly onto the supracondylar ridge
• the hamstring part has a tendinous dotal attachment to the adductor tubercle creating a gap, the adductor hiatus.
• the adductor part attaches proximally to the inferior ramus of pubis and ramus of ischium. innervation is obturator (L2-4)
• the hamstring part attaches proximally to the ischial tuberosity. innervation is tibial part of sciatic (L4)

Question 12

describe the location, action, innervation and attachment of gracilis

Answer 12

• long slender strap like muscle, the most medial muscle of the thigh. crosses knee joint as well as hip joint
• action is adduction of thigh, flexion of lower leg. minor medial rotation
• innervation is obturator (L2-4)
• proximal attachment is body and inferior ramus of pubis
• distal attachment is superior part of medial surface of tibia

Question 13

describe the location, action, innervation and attachment of obturator externus

Answer 13

• small flat muscle, deeply placed in the superomedial thigh (under pectinous)
• action is lateral rotation and steadying of head of femur
• innervation is obturator (L2-4)
• proximal attachment is margins of obturator foramen and obturator membrane
• distal attachment is trochanteric fossa of femur

Question 14

what are the boundaries of the femoral triangle

Answer 14

• superiorly the inguinal ligament
• medially by adductor longs
• laterally by sartorial
• the floor of the femoral triangle is formed y the illiopsoas laterally and the pectinous medially
• the roof is formed by the fascia kata and the cribiform fascia, sub cut tissue and skin

Question 15

what are the contents of the femoral triangle

Answer 15

• femoral nerve and its branches
• femoral sheath and its contents: the femoral artery and several of its branches, femoral vein and its tributaries, deep inguinal lymph nodes and associated lymphatic vessels
• these items then pass downwards through the adductor canal (an intramuscular pathway)

Question 16

describe the path of the femoral nerve

Answer 16

• originates (from L2-4 fibres) in psoas magir and descends posterolaterally to the midpoint of the inguinal ligament, passes deep to the ligament and enters the femoral triangle lateral to the vessels.
• subsequently divides into several branches including some to anterior thigh muscles, some articular branches to the hip and knee, some cutaneous branches etc.
• the terminal cutaneous branch of femoral is the saphenous nerve which descends through the femoral triangle lateral to the femoral sheath, accompanies it through the adductor canal and becomes superficial by passing between sartorial and gracilis. supplies the anteromedial skin on knee, leg, foot

Question 17

describe the path and branches of the femoral artery

Answer 17

• the femoral artery is the continuation of the external iliac. it enters the femoral triangle deep ti the midpoint of the inguinal ligament bisects the triangle and traverses the adductor canal. as it exits the adductor hiatus it becomes the popliteal artery. its branches supply the anterior and anteromedial aspects of thigh
• the deep artery of thigh branches off the femoral approx 1-5cm inferior to the inguinal ligament. it passes deeply between pectinous and adductor longs and gives off branches that wind around the femur thus supplying deep aspects of muscles in multiple compartments
• the medial circumflex femoral branches off the deep artery of thigh and passes posteriorly and medially between pectinous and iliipsoas into the gluteal region. supplies most of head and neck of femur and anastomoses with gluteal arteries
• the lateral circumflex femoral is also a branch of the deep artery of thigh. it passes laterally deep to sartoriusand rectus femoris. its branches supply anterior gluteal region, and some also wind around femur
• the obturator artery comes off the internal iliac artery and passes through the obturator foramen to enter the medial compartment of thigh supplying the adductors and ? some muscles in the gluteal region

Question 18

name the muscles in the gluteal compartment

Answer 18

• superficial layer: gluteus maximus, gluteus medius, gluteus minimus, tensor fascia lata. all have attachements to the posterolateral/external surface of the ilium and are mainly extensors, abductors and medial rotators of the thigh
• deep layer: pririformis, obturator internus, superior and inferior gemeli, quadratus femoris. these are all smaller muscles covered by the inferior gluteus maximus. have distal attachments on or distal to the the intertrochaneteric crest of the femur. act as lateral rotators of the hip and stabilise the hip joint

Question 19

what are the greater and lesser sciatic foramens

Answer 19

• formed from the greater and lesser sciatic notches by the sacrospinous and sacrotuberous ligaments respectively.
• the greater sciatic foramen is the passageway for structures entering or leaving the pelvis (eg. sciatic nerve). prirformis also exits through this foramen
• the lesser sciatic foramen is the passageway for structures entering or leaving the perineum (e.g. pudendal nerve)

Question 20

describe the location, innervation, attachments and action of the gluteus maximus

Answer 20

• the largest and most superficial gluteal muscle, covers all the other gluteal muscles except the anterosuperior third of gluteus medius
• proximal attachment is to the ilium, dorsal surface of sacrum and coxxyx and sacrotuberous ligament
• distally most fibres end in the iliotibial tract which inserts into the lateral condyle of tibia
• innervation is from the inferior gluteal nerve (L5, S1-2)
• action is extension of thigh, stabilisation, some lateral rotation. assists in rising from sitting position

Question 21

which bursae are associated with the gluteal bursae

Answer 21

• trochanteric bursa separates the superior fibres of gluteus maximus from the greater trochanter
• the ischial bursa separates the inferior part of the gluteus maximus from the ischial tuberosity (of ten absent)
• gluteofemoral bursa separates the iliotibial tract from the superior part of the proximal attachment of vastus laterals

Question 22

describe the location, attachments, innervation and action of gluteus medius

Answer 22

• fan shaped. lies in the superficial gluteal compartment partly under the gluteus maximus
• proximal attachment is the external surface of the ilium between the anterior and posterior gluteal lines
• distal attachement is the lateral surface of greater trochanter of femur
• innervation is from the superior gluteal nerve
• together with gluteus minimus and TFL acts to abduct and medially rotate thigh

Question 23

describe the location, attachments innervation and action of gluteus minimus

Answer 23

• fan shaped. lies in the superficial gluteal compartment completely under the gluteus maximus
• proximal attachment is to the external surface of ilium between anterior and posterior gluteal lines
• distal attachment is to the anterior surface of greater trochanter of femur.
• innervation is superior gluteal nerve
• acts together with gluteus medius and TFL to abduct and medially rotate the thigh

Question 24

describe the location, attachments, innervation and actions of TFL

Answer 24

• a fusiform muscle that is enclosed between two layers of fascia
• proximal attachment is ASIS and anterior part of iliac crest
• distal attachement is iliotibial tract which attaches to lateral condyle of tibia
• innervation is the superior gluteal nerve (L5, S1-2)
• action is abduction and medial rotation of the thigh. can also act as a flexor of the thigh in conjunction with iliopsoas

Question 25

describe the location, attachments, innervation and actions of piriformis

Answer 25

• narrow, pear shaped, leaves the pelvis through the greater sciatic foramen.
• note that the superior gluteal vessels and nerve emerge superior to it, the inferior gluteal vessels and nerve emerge inferior to it
• proximal attachment is anterior surface of sacrum, sacrotuberous ligament
• distal attachment is superior border of greater trochanter of femur
• innervated by branches of anterior rami of S1-2
• action is lateral rotation of extended thigh, abduction of flexed thigh, stabilisation of femoral head in acetabulum

Question 26

describe the location, attachments, innervation and actions of obturator internus and the superior and inferior gemelli

Answer 26

• form a tricipital/three headed muscle which occupies the gap between the piriformis and the quadratus femoris
• distal attachment for all three is in a common tendon which passes to the medial surface of greater trochanter
• the obturator interns is located partly in the pelvis where is covers most of the lateral wall of the lesser pelvis, it leaves the pelvis throughout he lesser sciatic foramen and makes a right angle turn becoming tendinous and receiving distal attachments of the gemeli and passing to the greater trochanter
• action is lateral rotation of extended thigh or abduction of flexed thigh
• innervation is ? obturator

Question 27

describe the location, attachments, innervation and actions of quadratus femoris

Answer 27

• short flat quadrangular muscle located inferior to obturator interns
• action is lateral rotation
• prox attachment is lateral border of ischial tuberosity
• distal attachment is quadrate tubercle on intertrochanteric crest of femur
• innervation is nerve to quadratus femoris

Question 28

name the muscles of the posterior thigh

Answer 28

• hamstrings: semitendinosus, semimembranosus, biceps femoris (long head)
• short head of biceps femoris

Question 29

describe the location, attachments, innervation and actions of semitendinosus

Answer 29

• action is extension of the thigh, flexion of leg and medial rotation in the flexion position. can also act to extend trunk
• prox attachment is ischial tuberosity
• distal attachment is medial surface of superior part of tibia
• innervation is tibial division of sciatic nerve (L5, S1-2)

Question 30

describe the location, attachments, innervation and actions of semimembranosus

Answer 30

• broad muscle with flattened membranous proximal attachment to ischial tuberosity
• distal attachment to posterior part of medial condyle of tibia
• innervation is tibial division of sciatic nerve (L5, S1-2)
• action is extension of thigh/flexion of knee, medial rotation of leg in knee flex position and trunk extension

Question 31

describe the location, attachmentsm innervation and actions of the two parts of biceps femoris

Answer 31

• action is flexion of leg and lateral rotation when knee is flexed. thigh extension
• proximal attachment of the long head is to the ischial tuberosity. its distal attachment is to the lateral side of the fibular
• proximal attachment of the short head is to the linea aspera and lateral suprcondylar line. distal attachment is also to lateral fibula
• innervation of the long head is from the tibial division of sciatic, to the short head is the common fibula division of sciatic