Lec 15 Lumbarsacral Plexus, Pelvis and Hip Flashcards
Know bony landmarks!
Inguinal ligament - where does it attach?
ASIS and pubic tubercle
What is important about the long axis of the shaft of the humerus?
its at an angle compared to the vertical weight-bearing line of gravity
Why would a femoral neck injury occur and who is it common in?
There is lots of pressure on the femoral neck because the angle of the femur
Common in people > 60, especially women because of lower bone density (estrogen) and greater femoral angle
What is meant by the femoral neck fracture is intrascapular?
fracture occurs inside the capsule, so surgery to repair fracture would have to cut open the joint capsule
Where does the sacrotuberous ligament run? What opening does it help create?
From the sciatic notch of the illium/sacrum to the ischial tuberosity
forms greater sciatic foramen
Where does the sacrospinous ligament attach? What opening does it help create?
from the sacrum to the ischial spine
forms the lesser sciatic notch
What does the greater sciatic foramen create a passage way for?
Lesser sciatic foramen?
Greater - structures entering or leaving the pelvis (like sciatic nerve)
Lesser - structures entering or leaving the perineum (pudendal nerve) aka going to the pelvic floor
What ligament is continuous inferiorly with the sacrotuberous ligament?
posterior sacroiliac ligament
What are the anterior SI joint ligaments?
lumbosacral ligament
iliolumbar ligament
know where they are!
(also anterior sacroiliac but not boxed)
What is the obturator membrane?
thing strong fibrous sheet that closes the obturator foramen
Where is the obturator foramen?
large opening in the pelvis, formed by the pubis and ischium bones. It is covered by the obturator membrane, with only a small opening for the obturator nerve and vessels to pass through. (obturator canal)
Where is the obturator canal?
smaller passage that is located at the superior part of the obturator foramen. It allows for the passage of the obturator nerve and blood vessels from the pelvis into the thigh. The canal is bordered by the obturator membrane and the bony edges of the foramen.
What else covers the obturator foramen (while leaving a tiny canal space)?
Obturator internas and externas muscles
Can the lower lumbar, SI, Sacral or Pelvic and Hip regions be moved independently?
No, they are tied together with ligaments and anatomical shaping of SI joint
What are the muscles of the posterior abdominal wall? What are these muscles commonly associated with?
Quadratus Lumborum
Psoas major and minor
illiacus
Back pain
What are the muscles of the anterior thigh acting at the hip joint?
Pectineus and Sartorius
Pectineus
MA: adducts and slightly flexes hip joint, assists with lateral rotation
PA: superior ramus of pubis
DA: pectineal line of femur
N: femoral nerve L2, L3 (may recive branch from obturator nerve)
Sartorius
MA:
- Flex, Abduct, lateral rotation of hip joint
- Flex knee and medial rotation leg when knee is flexed
PA: Anterior superior iliac spine (ASIS)
DA: superior medial tibia as part of pes anserinus
N: Femoral N L2 L3
The sartorius is __articulate
biarticulate
Superficial gluteal region consists of what?
What are their main actions?
consists of three large overlapping glutei - maximus, medius and minimus and the tensor fasciae latae
mainly hip extensors, abductors and rotators
Gluteus Maximus
MA: Extend hip (especially from flexed pos), assists in lateral rotation, fixes hip joint and rising from seated position
PA: ilium posterior to posterior gluteal line; dorsal surface of sacrum and coccyx; sacrotuberous ligament
DA: most fibers end in iliotibial tract (IT band) , which inserts into anterolateral tibial tubercle. some fibers insert on gluteal tuberosity
N: **Inferior gluteal nerve L5, S1, S2
What is a common problem/condition with the glute max?
It gets weak
Gluteus Medius
MA: abduct and medially rotate hip joint
- posterior fibers externally rotate (clam)
- keeps pelvis level when ipsilateral limb is weight-bearing and adv unsupported side during swing phase
PA: external surface of ilium between anterior and posterior gluteal lines
DA: lateral surface of greater trochanter
N: Superior gluteal nerve L5, S1
Gluteus Minimus
MA: Abduct and medially rotate hip
- also keeps pelvis level when ipsilateral limb is weight-bearing and adv unsupported side during swing phase
(same as medius without ER, just weaker at it)
PA: external surface of ilium between anterior and inferior gluteal lines
DA: Anterior surface of greater trochanter of femur
N: Superior gluteal nerve L5, S1
What is the most important muscle of the upper leg?
Glute medius
Tensor Fasciae Latae
MA: medially rotate hip! and abduct hip
- also keeps pelvis level when ipsilateral limb is weight-bearing and adv unsupported side during swing phase
PA: ASIS, anterior part of iliac crest
DA: iliotibial tract (IT band), which attaches to anterolateral tibial tuberosity
N: superior gluteal nerve L5, S1
*Which two muscles attach to the IT band?
TFL attaches to front of it
Glute max attaches to back of it
IT band syndrome
overuse condition
repetitive strain of IT band
runners and cyclists
friction between the soft tissue and lateral epicondyle causes pain and inflammation
What 6 muscles make up the deep gluteal layer? What action do they all do?
Piriformis
Obturator Internus (and externus?)
Superior and Inferior Gamelli
Quadratus Femoris
All do lateral hip rotation
Piriformis
MA: Laterally rotate extended hip, abduct hit when flexed, stabilize hip
PA: anterior surface of sacrum, ST ligament
DA: Superior border of greater trochanter of femur
N: Branches of anterior rami of S1 S2 (think sciatic!)
Obturator Internus
MA: Laterally rotate extended hip, abduct hip when flexed, stabilize hip
PA: pelvic surface of obturator membrane and surrounding bones
DA: medial surface of greater trochanter (trochanteric fossa of femur)
N: Nerve to obturator internus L5, S1
Superior and Inferior Gemelli
MA: Laterally rotate extended hip, abduct hit when flexed, stabilize hip
PA:
- superior; ischial spine
- inferior; ischial tuberosity
(think s for s)
DA: medial surface of greater trochanter (trochanteric fossa) of femur
N:
- superior; nerve to obturator interns L5 S1
- inferior; nerve to quadratus femoris L5 S1
(think whats above and below them!)
Quadratus Femoris
MA: laterally rotates hip and stabilizes hip
PA: lateral border of ischial tuberosity
DA: quadrate tubercle on the intertrochanteric crest of femur and area inferior to it
N: nerve to quadratus femoris L5 S1
Do a quick review of the 4 abdominal muscles!
External obliques - laterally flex and rotate contra, felx vertebral column
Internal obliques - laterally flex and rotate to same side, flex vertebral column
Rectus abdominis - flex vertebral column, tilt pelvis posteriorly
Transverse abdonmins - compresses and supports abdominal viscera
What spinal level does the aorta enter through the diaphragm? What does it come out as?
T12
Abdominal aorta
What does the abdominal aorta split into?
R common iliac
L common iliac
What does the R and L common illiac arteries split into?
internal and external iliac
small arterial branch comes off - internal iliac, then abdominal artery becomes external iliac artery
When does the external iliac artery become the femoral artery?
when it travels under the inguinal ligament
What is AAA?
Abdominal Aorta Aneurysm
What muscles make up the medial thigh group?
Adductor Longus
Adductor Brevis
Adductor Magnus
Gracilias
Obturator Externus
Adductor Longus
MA: adducts hip
PA: body of pubis inferior to pubic crest
DA: Middle third of linea aspera of femur
N: Obturator nerve and branch of anterior division L2 L3 L4
Adductor Brevis
MA: Adducts hip joint, to some extent flexes
PA: body and inferior ramus of pubis
DA: Pectineal line and proximal part of linea aspera of femur
N: Obturator Nerve and branch of anterior division L2 L3 L4
Adductor Magnus
MA:
- adduct hip
- adductor part: flexes hip
- hamstring part: extends hip
PA:
- adductor; inferior ramus of pubis and ramus of ischium
- hamstring; ischial tuberosity
DA:
- adductor; gluteal tuberosity, linea aspera, medial supracondylar line
-hamstring; adductor tubercle of femur
N:
- adductor: obturator nerve L2 L3 L4, branches of posterior division
- hamstring; tibial part of sciatic nerve L4
Gracilis
MA: adducts hip, flexes knee, medially rotates flexed knee
PA: body and inferior ramus of pubis
DA: Superior part of medial surface of tibia as part of pes anserinus
N: Obturator nerve L2 L3
Obturator Externus
MA: laterally rotates hip, stabilizes hip
PA: margins of obturator foramen and obturator membrane
DA: Trochanteric fossa of femur
N: Obturator N L3 L4
What three muscles compose the pes anserinus?
SARGENT
SGT
sartorius, semitendinosis, gracilis
What covers the saphenous opening? What goes through it?
The femoral sheath of TFL acts as a flap over the saphenous opening where the great saphenous vein can go through and empty into the femoral vein
IN THE FEMORAL TRIANGLE
saps drains into femoral
Where does the saphenous nerve begin? Sensory or motor?
starts in inguinal as a branch of femoral nerve
sensory innervation
What are the borders of the femoral triangle?
Adductor longus
Pectineus (floor)
Sartorius
Inguinal ligament
What travels through the femoral triangle?
VAN
femoral artery, vein, nerve
and saphenous nerve but not on slide?
What happens at the adductor hiatus? Where does the adductor canal start?
opening near the end of the femur where the femoral artery and vein cross knee posteriorly
they don’t stay anterior!
adductor canal starts at the apex of the femoral triangle
Are there any nerves lying directly on the femur?
No, so limited injury can occur in that sense
Describe the parent structures/name changes of venous return starting with the IVC
IFC splits into L and R common iliac vein, the internal iliac vein comes off as a branch and the external iliac vein continues
becomes femoral vein under the inguinal ligament
just like arterial!
**great saphenous vein drains into femoral vein
what can the great saphenous vein be used for?
can be cut out in surgery and used for bypass for clogged coronary artery
What are the big 5 of the lumbosacral plexus?
Femoral N L2-L4
Obturator N L2-L4
Sciatic N L4 L5 S1 S2 S3
Superior Gluteal Nerve L4-S1
Inferior Gluteal N L5-S2
(don’t forget pudendal S2-S4!)
Know what foramen the big 5 go through
Femoral Nerve: Passes through the inguinal canal, but is primarily located in the iliopsoas muscle area after emerging from the pelvis.
Obturator Nerve: Exits the pelvis through the obturator foramen.
Superior Gluteal Nerve: Exits the pelvis through the greater sciatic foramen, above the piriformis muscle.
Inferior Gluteal Nerve: Also exits the pelvis through the greater sciatic foramen, but below the piriformis muscle.
Sciatic Nerve: Exits the pelvis through the greater sciatic foramen, typically below the piriformis muscle.
PERIPHERAL AND MOTO INNERVATION PATTERNS
MOTOR
posterior leg - sciatic nerve, common fibular branch comes off at knee
anterior leg - mostly femoral nerve, obturator on upper medial thigh, common fibular nerve wraps around to outer lower leg
PERIPHERAL
What is compartment syndrome? How can it be trated?
when the fascia between compartments gets so tight it compresses the muscles
pain, pallor, paresthesia, pulselessness, paralysis
fasciotomy - cut strips of fascia to let muscles breathe
