Sievert: Gluteal region, thigh, and popliteal fossa Flashcards
What nerve roots make contributions to the femoral and obturator nerves?
L2, L3, L4
What nerve roots make contributions to the sciatic nerve?
L4, L5, S1, S2, S3
The lower limbs come off as a limb buds, with the posterior compartment facing anteriorly. They undergo (blank) degrees of medial rotation, so that the original posterior compartment becomes the anterior compartment. What happens to the nerve supply?
180; nerves supply of the posterior compartment is carried with it during rotation, so that nerves innervating the anterior compartment are really posterior division nerves
What happens to dermatomes as a result of the medial rotation of the lower limbs that occurs during development?
dermatomes also get rotated, ex: L4 begins posteriorly, but wraps around the leg laterally and ends at the medial foot!
In adults, anterior compartment lower limb muscles are considered (blank)
extensors
Obturator nerve begins anterior lateral. How does it end up? Is it an anterior or posterior division nerve?
posterior medial; it is an anterior division nerve
What nerve supplies the anterior thigh?
femoral nerve
What nerve supplies the anterior leg?
fibular (peroneal)
What nerve supplies the posterior thigh?
tibial
What nerve supplies the posterior leg?
tibial
What nerve roots allow for the following:
Hip flexion
Knee extension
Ankle dorsiflexion
Hip extension: L2/3
Knee extension: L3/4
Ankle dorsiflexion: L4/5
What nerve roots allow for the following: Hip extension: Knee flexion: Ankle plantarflexion: Plantar foot muscles:
Hip extension: L4/5
Knee flexion: L5/S1
Ankle plantarflexion: S1/2
Plantar foot muscles: S2/3
What is plantarflexion? What is dorsiflexion?
taking the bottom of the foot and flexing it down; taking the bottom of the foot and extending it up toward the body
What’s the dermatome to the little toe? Why is this dermatome important to remember?
S1; the most common herniated disc is L5/S1, and this will send shooting pain down to the little toe
What is the dermatome of the big toe?
L4/5
Is it more important for the joints of the lower limb to be mobile or strong?
STRONG
What is the pelvic girdle made up of?
hip bones and the sacrum
What’s the superior border of the thigh? What’s the inferior border?
acetabulum; knee
What’s the superior border of the leg? What’s the inferior border?
knee; ankle
Sacroiliac joint needs what three ligaments?
sacroiliac
sacrotuberous
sacrospinous
The obturator internus heads posteriorly from the obturator foramen, wraps around under the lesser sciatic notch, comes out, and attaches where? Where does the obturator externus attach?
intertrochanteric fossa of the femur; externus also attaches to the intertrochanteric fossa, but heads straight back rather than wrapping around
What can happen at the head of the femur in young active children?
The main supply to the head of the femur comes in at the neck and then supplies the head. There is potential for spontaneous regression of blood supply in children. They will complain of groin pain. Treatment involves staying off of the femur, and allowing blood supply to return so that there is no permanent damage to the femur.
Legg Calve perthes
spontaneous loss of blood flow to the head of the femur in children - may lead to total necrosis
3 types of fractures that can occur to the femur
fracture of femoral neck
intertrochanteric fracture
spiral fracture
There are three compartments of the thigh. What are they each surrounded by?
anterior, posterior, medial; thick fascia lata
Where is the fascia lata the thickest?
lateral surface of the thigh, where it forms up the IT band
The anterior compartment muscles surround the femur. What nerve is associated with these muscles? What nerve is associated with the posterior compartment? The medial compartment?
femoral nerve; sciatic; obturator
Where does lymph from deep structures of the lower limb drain to? Where does lymph from superficial structures drain to?
popliteal nodes; inguinal nodes –> iliac nodes –> abdominal nodes –> cysterna chyli
What connects superficial and deep veins in the lower extremities? What happens if these connections become faulty? (What are the superficial veins of the lower limb?)
Perforating vessels connect the superficial and deep veins. If these vessels lose competency in their flow (their valves becomes weak), excess blood from the deep veins will flow to the superficial veins and cause varices. (Greater and lesser saphenous are superficial veins of the lower limb).
When does the external iliac become the femoral artery?
after it crosses the inguinal ligament
The femoral artery gives off this branch, which is the main supply to the posterior compartment of the thigh.
deep femoral (profunda)
The deep femoral artery has small vessels called (blank)
perforators
The femoral artery continues down the thigh and supplies the anterior thigh muscles. It changes its name as it passes through the adductor hiatus behind the knee. What does it become?
popliteal artery
The popliteal artery (continuation of femoral) continues down the leg and divides into what two branches? Which branch gives off the fibular artery? What is the segment before this division referred to as?
anterior and posterior tibial; posterior tibial gives off the fibular; tibfib trunk
What anastamosis provides collateral circulation at the hip?
cruciate anastamosis
List the 4 contributions to the cruciate anastomosis
1st perforating branch of the deep femoral artery
inferior gluteal artery (from above)
medial/lateral circumflex arteries (from femoral artery)
What fascial layer creates the femoral sheath? There are three compartments within the sheath–list them from lateral to medial. What is contained in the femoral canal? Is the femoral nerve within the sheath? Where is it in relation to the femoral sheath?
transversalis fascia; femoral artery, femoral vein, femoral canal; lymphatics; no femoral nerve; femoral nerve lies lateral to the femoral sheath
What vein pierces the femoral sheath to gain access to the femoral vein?
great saphenous vein
What are the borders of the femoral sheath?
superior: inguinal ligament
medial: lacunar ligament
inferior: pectineal ligament
lateral: femoral artery
Why is the femoral canal significant? Note that the femoral sheath blends with the fascia of the thigh. Why is this relevant?
there is potential for a femoral hernia to pass through; hernias cannot go very far down, because they become trapped where the transversalis fascia of the sheath fuses with the fascia lata (investing fascia) of the thigh.
If a femoral hernia passes through the femoral canal, where will it protrude into?
the vicinity of the femoral triangle
3 boundaries of the femoral triangle? Is the femoral triangle well protected?
inguinal ligament (superior)
adductor longus (medial)
sartorius (lateral)
This area is not well protected, and is very vulnerable to injury by sharp objects
At the inferior aspect of the femoral triangle, the femoral artery and vein enter what is known as the adductor canal. What muscle do these vessels pierce to gain access to the posterior thigh and the popliteal fossa?
pierce the adductor magnus at the adductor hiatus
List three nerves that are carried down into the thigh from the lumbar plexus
- lateral femoral cutaneous (lateral cutaneous)
- femoral nerve (anterior thigh)
- obturator nerve (medial thigh)
What two muscles blend together as they exit the pelvis, continue down toward the thigh, cross beneath the inguinal ligament, and become tendonous as they insert into the lesser trochanter of the femur?
iliacus
psoas
Where does the iliopsoas attach to the femur? What movements is this muscle involved in?
lesser trochanter (posterior); flexion at the hip and lateral rotation (as it contracts, it can “unwind” the head of the femur)
Where does the pectineus originate? Where does it attach? Where is it in relation to the iliopsoas muscle?
Pectineus comes off of the pubic bone and attaches to the femur along the adductor line. It lies just medial to the iliopsoas.
Where does the sartorius originate? Where does it attach? It crosses the hip joint anterior to the axis, so what are its actions?
Sartorius (longest muscle in the body) comes off of the anterior superior iliac spine and attaches on the posteriomedial aspect of the tibia (back of the knee). It causes flexion on the transverse axis, lateral rotation, and flexion at the knee (think of a tailor sitting). **Also medially rotates knee
What are the four bellies of the quadriceps? Which ones cross the hip joint? (Where are the others attached if they do not cross the hip joint?)
rectus femoris ** crosses hip joint vastus lateralis (laterally, beneath IT band) vastus intermedius (right beneath rectus femoris) vastus medialis (the others are attached to the femur -- only affect the knee -- no action at the hip joint)
What is the main function of the 4 bellies of the quadriceps? How do these muscles attach to the patella? What extends from beneath the patella to the tibial tuberosity?
extension at the knee **the rectus femoris also flexes the thigh; these muscles combine to form a strong CT band called the patellar tendon, which attaches them to the patella. The patellar ligament attaches the patella to the tibial tuberosity.
What innervates the pectineus, the sartorius, and the 4 bellies of the quadriceps?
femoral nerve
**pectineus may be innervated by the obturator nerve
List the flexors of the hip joint. Which is the most powerful?
iliacus and psoas **most powerful flexors
sartorius
pectineus
tensor of fascia lata
What innervates the iliacus, psoas, sartorius, and pectineus? What innervates the tensor of the fascia lata? Does this muscle attach to bone?
femoral nerve; tensor of fascia lata has a different innervation from the superior gluteal nerve; it doesn’t attach to bone, but to fascia
This nerve is a branch off of the femoral nerve that travels with the femoral artery and vein through the adductor canal. Does it pass posteriorly through the adductor hiatus with the femoral artery and vein? Where does it go?
saphenous nerve; diverges from the artery and vein before the adductor hiatus and goes onto the superficial medial portion of the thigh
The narrow space in the middle third of the thigh between the vastus medialis and adductor muscles, converted into a canal by the overlying sartorius muscle.
adductor canal
The adductor canal extends from the apex of the femoral triangle. Where does it end? What passes through the canal?
ends at the adductor hiatus (in the tendon of the adductor magnus); contains femoral artery, vein, and saphenous nerve
What nerve roots make up the femoral nerve? What does the femoral nerve supply? What actions is it important for?
L2-L4; supplies muscles of the anterior thigh (pectineus, sartorius, quadriceps) and the iliopsoas; important for thigh flexion and knee extension
What nerve supplies the lateral thigh? What nerve supplies the posterior compartment of the thigh, the medial thigh, and runs down along the medial and posterior side of the foot?
lateral cutaneous nerve; saphenous nerve
What are the medial thigh adductors? Which is most medial? Which of these are innervated by the obturator nerve?
adductor longus adductor magnus adductor brevis gracilis pectineus ** only muscle not solely innervated by obturator (may be innervated by femoral nerve)
Medial adductors originate from the posterior pubic bone and insert at the adductor line of the femur. They pass inferior to the AP axis, but anterior to the vertical axis, so what two actions can they perform?
adduction; medial rotation
List the medial muscles of the thigh
adductor longus adductor brevis **attaches higher up on femur adductor magnus **2 heads gracilis **crosses 2 joints obturator externus
Why is the obturator externus an exception to the medial group muscles?
It is the only medial group muscle that is not an adductor or medial rotator. It is a lateral rotator, but is associated with these muscles, because it is innervated by the obturator.
What are the two heads of the adductor magnus? Which is higher? What is the innervation to each head?
adductor head **higher
hamstring head;
adductor head is innervated by the obturator, while the hamstring head is innervated by the tibial nerve (from the sciatic)
What is a key feature of the adductor magnus?
adductor hiatus, which allows for passage of the femoral artery and vein on their way to the popliteal fossa
What is the only medial muscle group that crosses 2 joints? What action does it have at each joint - hip and knee?
gracilis; hip –> adductor and medial rotator, knee –> flexion
What roots make up the obturator nerve? What muscles does it supply?
L2-L4; adductor compartment (sometimes the pectineus) **only the adductor part of the adductor magnus
Review: upper part (adductor) of the magnus is supplied by what nerve? Lower part (hamstring)?
obturator; tibial (sciatic)
What happens to the obturator nerve as it comes out under the pectineus? What muscle does it split around?
it splits around the adductor brevis into an anterior and posterior component
What are the cutaneous branches on the posterior gluteal region called? What are these extensions of? What are the three branches? What do they supply?
cluneal nerves; these are extensions of dorsal rami that were going to back muscles; superior, medial, and inferior cluneal branches; these supply sensory/cutaneous innervation to the posterior gluteal region
Where does the gluteus maximus arise from? Where does it attach? What is its action of the transverse axis? What is its action on the vertical axis? When is this muscle used?
iliac crest, sacrum, and sacrotuberous ligament; gluteal tuberosity of the femur and IT band; extension and lateral rotation (posterior to vertical axis); this muscle is called into play during powerful extension only, and it is not typically used during walking
Where do the gluteus medius and minimus arise from? Where do they attach to the femur? They are attached lateral to the AP axis, so what does this allow them to do? Why is this important for walking? What kind of gait can result without them?
gluteal surface and wings of the ilium; attach to the greater trochanter of the femur; they are powerful abductors; when one foot is lifted off the ground, these muscles keeps the other side of the pelvis level. They are essential for walking **Trendelenburg gait
Review: main action of the gluteus maximus?
Main action of the gluteus medius/minimus?
extend and laterally rotate; abduct and medially rotate
Which muscle has some attachment anterior, posterior, and right through the axis of the hip joint, and is thus reminiscent of the deltoid? It can medially rotate, laterally rotate, flex, extend, and abduct.
gluteus minimus (gluteal muscles collectively, but mostly minimus)
Where does the tensor fasciae latae muscle arise from? Where does it attach? Because of its attachment to the IT band, what actions does it have at the knee? What actions does it have at the hip?
tensor fasciae latae comes from the anterior superior iliac spine and runs down to the IT band. It is innervated by the superior gluteal nerve. This muscle allows for flexion of the knee, can help stabilize during extension of the knee, and allows for medial rotation and flexion at the hip.
What innervates the gluteus maximus? Medius and minimus? Tensor fasciae latae?
gluteus maximus: inferior gluteal nerve
minimus/medius/tensor fasciae: superior gluteal nerve
The sciatic nerve typically comes out inferior to the piriformis muscle; however, it may pass through the piriformis (or even split around it). If it passes thru the piriformis, what can this cause? How does it present?
piriformis syndrome – if the piriformis becomes too tight, it can compress the sciatic nerve; this presents like a herniated disc
What are some anomalies of the sciatic nerve as it crosses the piriformis muscle?
It can come out beneath the piriformis (most common); can split into the tibial and fibular before passing through; can split around the piriformis
What is the group of muscles that are inferior to the piriformis and deep to the sciatic nerve?
short lateral rotators
Where should injections be performed in order to avoid the sciatic nerve?
upper lateral quadrant of iliac crest
What’s this:
denervation of gluteus medius/minimus
inability to abduct the hip on that side
unsupported limb sags
Trendelenburg’s sign
Where do the inferior and superior gluteal arteries arise from?
the anterior (inferior) and posterior (superior) divisions of the internal iliac artery
The inferior gluteal joins with the cruciate anastomosis and can supply the lower limb through the descending branch of the (blank)
lateral femoral circumflex
What are the 6 lateral rotator muscles?
PGOGOQ Piriformis Gemellus superior Obturator internus Gemellus inferior Obturator externus Quadratus femoris
After the obturator internus leaves the pelvis through the lesser sciatic notch, is it still a muscle? What two muscles run with the obturator internus? Where do all of three of these muscles attach?
no, it is tendonous; gemelli run superior and inferior to the obturator internus **these muscles arise from the same tendon; all muscles enter into the intertrochanteric fossa
Aside from the 6 short lateral rotators, what is another major lateral rotator?
gluteus maximus
What innervates the PGOGOQ short lateral rotators?
small branches from the lumbosacral plexus
Do lateral rotators have other functions?
No, just turn away from a planted foot (laterally rotate)
What innervates the obturator externus?
obturator nerve **passes right through it
Where do the posterior thigh muscles arise from?
ischial tuberosity
lateral supracondylar line **short head of biceps
Where do the posterior thigh muscles insert?
- biceps
- semimembranous
- semitendinosus
- head of the fibula**long and short head of biceps
- rough area below medial condyle of tibia
- tibial tuberosity
Which posterior thigh muscles cross 2 joints?
all but short head of the biceps
All posterior thigh muscles cross the knee posterior to the transverse axis, so what action do they have?
flex the knee
What are the hamstrings important for? What can happen as a result?
The hamstrings are important for tonic contraction and stabilization during posture changes (ex: lean forward and hammies tighten). Long-term tonic contraction leads to tightening and causes these muscles to shorten up.
Long muscles that cross the knee joint are important for flexing, but can also perform what actions?
medial and lateral rotation
List the three hamstring muscles (most span 2 joints: the hip and knee) and the two other muscles of the posterior thigh (cross 1 joint)
semitendinosus (medial) semimembranosus (middle) long head of biceps femoris (lateral) short head of biceps *1 joint adductor magnus (hamstring part -- forms adductor hiatus)
What innervates the posterior thigh muscles?
sciatic nerve
What does the sciatic nerve split into?
tibial nerve
common fibular nerve
What does the tibial nerve supply? Why is there an exception?
all hamstrings except the short head of the biceps (common fibular); short head of the biceps is far enough anterior that it is supplied by an anterior division nerve **common fibular
What is the blood supply to the hamstrings?
primarily the perforating branches of the profunda femoris - these go through the adductor magnus and provide sole source of blood
What is the only motor innervation to muscles below the knee joint? There are many cutaneous components, but no other motor innervation.
sciatic nerve
What is the major blood supply to the leg?
femoral artery which becomes popliteal
Common hamstring injury
evoltion of the hamstring off of the ischial tuberosity
Borders of popliteal fossa – diamond
superior: hamstring muscles
superior lateral: long and short head of biceps
superior medial: semitendinosus/semimembranosus
inferior lateral: lateral head of gastrocnemius
inferior medial: medial head of gastrocnemius
What is contained deep in the popliteal fossa?
popliteal lymph nodes
popliteal artery and vein
tibial nerve and common fibular nerve (branches of sciatic)
genicular arteries
What is the order of artery, nerve, and vein in the popliteal fossa?
popliteal artery, popliteal vein, nerve (common fibular nerve being most lateral as it wraps around the fibula) from medial to lateral
Why are the genicular arteries important?
provide collateral flow when you compress the popliteal artery, ex: baseball catcher
What is contained superficially in the popliteal fossa?
small saphenous vein
terminal branches of posterior cutaneous nerve of the thigh
Can you feel a pulse at popliteal fossa?
yes, but its difficult due to the fat
What does the popliteal artery divide into after crossing behind the knee joint?
anterior tibial and posterior tibial (tib-fib trunk)
The sciatic nerve divides into what two branches?
tibial and common fibular nerves
What does the common fibular nerve divide into?
superficial and deep fibular nerves
fluid-filled herniations of the synovial membrane of the knee joint
popliteal cyst
Which branch of the sciatic nerve stays in the posterior compartment of the adult leg?
Which branch goes around to take care of anterior and lateral compartments, and breaks up into a superficial and a deep branch?
tibial; fibular
What nerves make up the superior clunial nerves?
dorsal rami of L1-L3
What nerves make up the medial clunial nerves?
dorsal rami of S1-S3
What nerve makes up the inferior clunial nerves?
posterior femoral cutaneous nerve of the thigh
What nerve provides cutaneous innervation to the anterior thigh? Lateral thigh? Posterior thigh?
intermediate femoral cutaneous; lateral femoral cutaneous; posterior femoral cutaneous
Is the intertrochanteric crest found on the anterior or posterior aspect of the femur?
posterior
The femoral nerve divides into a (blank) and a (blank) division in the thigh. The anterior division gives off cutaneous branches and muscular branches. List a few cutaneous branches. The posterior division provides innervation to the 4 bellies of the (blank).
anterior; posterior; intermediate femoral cutaneous and medial femoral cutaneous nerve; quadriceps
What nerves comprise the lumbosacral plexus? What are the ANTERIOR division nerves? What are the POSTERIOR division nerves?
T12, L1, L2, L3, L4
Anterior: tibial, obturator
Posterior: femoral, gluteals, fibular (peroneal)
