Anatomy

Question 1

What structures exit the lesser sciatic foramina?

Answer 1

the sciatic foramina are separated by the sacrospinous ligaments
contents:
* obturator internus tendon
* internal pudenal artery and vein
* pudendal nerve

Question 2

What structures exit the greater sciatic foramina?

Answer 2

passage way for structures to pass from the pelvis to gluteal region
divided by relationship to piriformis
suprapiriformis:
* superior gluteal artery nerve and vein

infrapiriformis
* sciatic nerve
* inferior gluteal nerve artery vein
* nerves to obturator internus and quadratus femoris
* pudendal nerve
* posterior femoral cutaneous nerve

Question 3

Describe the boundaries and contents of the femoral triangle

Answer 3

Boundaries:
superior - inguinal canal
medial - adductor longus
lateral - sartorius
roof - fascia
floor - iliopsoas, pectineus and adductor longus

contents
- femoral nerve, artery and vein and lymph nodes

Question 4

Describe the anatomy of the sciatic nerve

Answer 4

originates from the lumboscaral plexus L4-S3
* leaves the greater sciatic notch to enter gluteal region
* emerges below piriformis
* doesn’t supply gluteal muscle but 2 branches are given off here:
* nerve to obturator internus and quadratus femormis
* descends in the posterior compartment to give off the 2 main branches just above the popliteal fossa

2 main branches:
* peroneal branch
* tibial branch

Question 5

What is the corona mortis?

Answer 5

Corona mortis: vascular communication between obturator A and inferior epigastric artery.

Question 6

What is the nerve supply to the short external rotators?

Answer 6

piriformis nerve (S1,2) peroneal branch of sciatic nerve
piriformis

nerve to obturator internus (L5,S1,S2) tibial branch of sciatic nerve
obturator internus
superior glemellus

nerve to quadratus femoris (L4,5,S1) tibial branch of sciatic nerve
inferior glemellus
quadratus femoris

Question 7

Draw the trabecular pattern of the proximal femur

Question 8

What are the zones for acetabular screw placement

Answer 8

Four quadrants

posterior-superior
ideal zone
risk of sciatic nerve, sup glut nerve and vessels

posterior-inferior
safe if screws <20mm
risk to sciatic nerve, inf glut nerve and vessels

anterior-inferior
DANGER ZONE
obturator nerve, artery and vein

anterior-superior
DANGER ZONE
external iliac artery and vein

Question 9

Which muscles cross the knee and hip?

Answer 9

rectus femoris

origin - AIIS and ilium
insertion - quads tendon
nerve supply - femoral nerve L3, L4
movement - flexes hip and extends knee

Biceps

origin
long head - ischial tuberosity - tibial portion sciatic nerve
short head - lateral supracondylar ridge of femur - Common peroneal portion of sciatic nerve
insertion - lateral tibial condyle
movement - extends hip and flexes knee

semimembranous

origin - ischial tuberosity
insertion - medial condyle of tibia
extends hip and flexes knee

semitendinous

origin - ischial tuberosity
insertion - upper medial shaft of tibia
extends hip and flexes knee

Question 10

Which muscles of the thigh have dual innervation

Answer 10

adductor magnus
adductor portion - obturator nerve
hamstring portion - tibial portion of sciatic nerve
pectineus
ant division of femoral nerve
may recieve branch of obturator nerve