20 - MSK Hip to Knee

Question 1

What is the sciatic nerve made of
where does it exit

Answer 1

consists of tibial and fibular nerves glueed together by epineurium

exits the greater sciatic foramen formed by the sacrospinous ligament

Question 2

What are the abductors of the hip
What innervates

Answer 2

gluteus maximus (inf gluteal) and tensor facia lata (sup gluteal nerve)
work together through the iliotibal tract

Question 3

Which muscle do gluteal nerves pass through

Answer 3

piriformis muscle (external rotator)

Question 4

Where do adductor group muscles arise from
What innervates

Answer 4

pelvic bones (ischium and pubis) and interosseus membrane of the obturator foramen to insert on the medial shaft of the humerus and proximal tibia

obturator nerve

Question 5

What is the adductor hiatus

Answer 5

hole through the muscle
“pause”

can contribute to the entrapment of the femoral nerve

Question 6

What is the sartorius muscle
Waht does it do
What is it innervated by

Answer 6

part of anterior (extensor) compartment

flexion of hip
flexion of knee
external rotation of the thigh

femoral nerve

Question 7

What are the three bones that make up the acetabulum

Answer 7

ilium
pubis
ischium

Question 8

What are the ligaments of the hip

Answer 8

iliofemoral
pubofemoral
ischiofemoral
ligamentum teres

Question 9

When is the hip most stable

Answer 9

when extended (tight ligaments)

flexion is unstable (loose ligaments)

Question 10

When are hip dislocations likely to occur
which way does it dislocate

Answer 10

when in flexion

posterior direction

Question 11

What can happen in a hip dislocation

Answer 11

compression or injury of the sciatic nerve

loss of muscle tone in the anterolateral compartment of the leg = foot drop

foreshortened interanal rotation
(adductor group)

Question 12

What happens in a hip fracture
What could happen as a result

Answer 12

fracture of femoral neck
avascular necrosis

foreshortened external rotation
(iliopsoas via lesser trochanter)

Question 13

What are the muscles of the quads

What are the innervated by

Answer 13

vastus medialis
vastus intermedius
vastus lateralis
rectus femoris

femoral nerve

Question 14

What do the quads do

Answer 14

extension of knee (major function)
flexion of hip (minor function)

Question 15

What are the muscles of the hamstrings

What innervates

Answer 15

semi-membranosus (medial)
semi-tendinosus (intermediate)
biceps femoris (lateral)

tibial nerve

Question 16

What do the hamstrings do

Answer 16

flexion of the knee (major function)
extension of the hip (minor function)

Question 17

Which muscles insert upon the medial aspect of the proximal tibia

Answer 17

goose’s foot

sartorius, gracilis, semi-tendinosus
femoral, obturator, tibial

three muscles from each compartment

where the three tendons on the inside of knee attaches to the lower leg

Question 18

What does the bursa do

Answer 18

protects the tendons of the pes anserinus from the underlying bone (medial epicondyle) of the femur

Question 19

What are the ligaments of the knee

Answer 19

lateral (fibular) and medial (tibial) collateral ligaments: keep knee stable

cruciate ligaments: prevents shin bone from sliding out in front of the tibial bone

menisci: improve the fit between the tibial plateau and the rounded femoral condyles
- medial
- lateral (undergoes conformation change as the knee moves through flexion and extension)

Question 20

Which aspect of the femoral condyle interact with teh tibia when the knee is in extension

Answer 20

anterior

Question 21

Which aspect of the femoral condyle interact with the tibia when the knee is in flexion

Answer 21

wider posterior

Question 22

What does the popliteus muscle do
What innervates

Answer 22

contraction of the popliteus muscle –> external rotation of the femur + draws the lateral meniscus posterior
(to help unlock the extended knee)

tibial nerve

Question 23

Which ligaments support the knee

Answer 23

collateral ligaments (lateral fibular and medial tibial) prevent lateral displacement of the tibia wrt the femur

Cruciate ligaments prevent anterior/posterior displacemnet of the tibial wrt the femur

Question 24

Which cruciate ligament is smaller and weaker/more prone to tearing (sprains)

Answer 24

anterior cruciate ligament (acl)

prone to tearing when rotational forces are place on the knee

Question 25

How to test the integrity of the ACL

Answer 25

perform and anterior drawer test

ability to open the drawer = ACL damage

Question 26

When is the PCL prone to tearing

Answer 26

when the knee is hyperextended or a force is applied ot the anterior tibia when the knee is flexed

Question 27

How to test the integrity of the PCL

Answer 27

perform a anterior drawer test

ability to close the drawer = PCL dmage

Question 28

What can happen if forces are applied to the lateral aspect of the knee

Answer 28

injury to structures on the medial side of the knee (attached to one another)
- anterior cruciate ligament (ACL)
- medial collateral ligament (MCL)
- medial meniscus (MM)