The Pelvis and hip joint Flashcards
What does the pelvic girdle connects?
- vertebral column to the femurs
How is the pelvic girdle different to the shoulder girdle?
- much stronger and less flexible
How many bones are there in the pelvic girdle and what are there?
3 bones
- left hip bone
- right hip bone
- sacrum
How many joints are there in the pelvic girdle and what are they?
- 2 sacroiliac joints
- pubic symphysis joint
What is the role of the pelvic girdle?
- strong and stable
- supports weight of the body
- protects organs and blood vessels
What is the real life position of the pelvic girdle (how is it positioned in the body)?
- it is slightly tipped forwards
- like a bowl tipped forwards
What is another word for the hip bone?
the innominate bone
What are the three sections the innominate bone/hip bone is divided into?
- ilium
- ischium
- pubis
How do the ilium, ischium and pubic parts of the bone develop?
separately
What is the name of the area where the ilium, ischium and pubis fuse?
Acetabulum
What is the acetabulum?
the socket that articulates with the femoral head - forming the hip joint (holds the head of the femur)
What is the ilium made up of?
Ala and body
Where is the triradiate cartilage?
made up of 3 cartilages and is in the acetabulum.
What type of joint is the hip joint? (2)
- ball and socket joint
2. synovial joint
Where is the hip joint?
between the head of the femur and the acetabulum of the innominate bone
How is stability provided by the hip joint? (3)
- Acetabular anatomy
- Fibrous capsule
- Ligaments
What are the ligaments of the hip joint? (3)
- Ileofemoral
- Pubofemoral
- Ischiofemoral
What is the articular surface of the acetabulum like?
- smooth
- crescent shaped - lunate surface
What is the inferior deficiency of the acetabulum called?
Acetabular notch
What is the ace tabular notch bridged by?
transverse acetabular ligament
What is the acetabular labrum and what is it’s role?
- a rim/lip of cartilage
- role - deepens the articular surface
What is the fibrous capsule like?
- strong and dense
What aspect of the fibrous capsule enables the hip joint to move around?
- the fact that it is loose and strong
What does the proximal attachment of the fibrous capsule encircle?
the rim of the acetabulum
Where is the distal attachment of the fibrous capsule?
- femoral neck
- intertrochanteric line
- greater trochanter
How does the iliofemoral ligament cover the hip joint?
superiorly and inferiorly
What is the strongest ligament of the hip joint?
illiofemoral ligamnet
What is the role of the illiofemoral ligament?
- prevents hyperextension of the hip during standing
- as it screws into the femoral head
How does the pubofemoral ligament cover the hip joint?
-inferiorly and anteriorly
What shape is the illiofemoral ligament?
Y shaped ligament
How does the pubofemoral ligament attach to the femur?
- attaches to the femur distally
How does the ischiofemoral ligament cover the hip joint?
posteriorly
What is the weakest ligament of the hip joint?
ischiofemoral ligament
How do the ligaments improve stability to the hip joint? ( 3 steps)
- Spiral around the hip joint
- Become taut when hip is extended
- This pulls the femoral head into the acetabulum
What is the pelvic girdle?
strong ring of bone
What is the pelvic girdle formed by?
sacrum and 2 innominate bones
What is the the innominate bone formed by? (3)
- illium
- ischium
- pubic bones
What is the point of fusion for the illiim, pubic and ischium?
acetabulum - the socket of the hip joint
What injuries can occur at the hip joint? (3)
- fractured to the pelvic ring
- dislocation of the hip joint
- fracture to the neck of the femur (hip fracture)
What can the problems (congenital problems) children may have with the development of the hips lead to with the joints? (3)
lead to joint:
- laxity
- sublaxation
- dislocation
of the hip
Where is the force likely to come from in a pubic rami fracture?
lateral force - significant trauma
likely to have other fractures - widening of the sacro-iliac joint
What is the cause of an open book pelvic fracture?
straight on force - motorbike accidents and mountain bike
What is a worry in an open book fracture?
internal damage to urethra and bladder
At what joint does a fracture of the neck of the femur usually occur at?
sacral-femur joint
When is posterior dislocation of the hip joint likely to occur at?
- car accident
- When some is in a sitting in a drivers seat position with knees bent = seated position
- hip is flexed, internally rotate and adducted
What nerve is at risk in posterior dislocation?
sciatic nerve
Will the patient be able to move their limb out of the posterior limb position?
no
How is posterior dislocation resolved?
- slotting the joint back into place
- using gas and air or sedation
What type of fracture can you get with posterior dislocation?
- acetabular fractures
When does anterior dislocation occur?
- when force is applied during extreme abduction with external rotation of hip
how is the femoral head positioned in anterior dislocation?
the femoral head is levered out
How does the limb appear in anterior dislocation? (3)
- externally rotated
- Abducted
- Flexed
How common is anterior dislocation?
not very
Is the sciatic nerve at risk in anterior dislocation?
no
What is at risk in anterior dislocation?
- femoral artery, vein and nerve
What is used to help slot the anterior dislocation back into place and what does these means allow?
- sedation
- analgesia
allows the muscles to relax as they are contracted
What is medial dislocation also known as?
acetabular fracture
What is medial dislocation/acetabular fracture caused by?
fall from a height - force coming upwards
What other features are medial dislocation and acetabular fracture likely to have?
- hypotension
- tachycardia
- internal injuries - puncture of uterus,bladder
- shock
- internal bleeding if puncture vessels
How may disruption the blood supply to the femoral head occur?
blood vessels may be torn or stretched
What may occur to some branches of the blood supply to the femoral if they are disrupted?
may remain kinked or compressed until the hip is reduced
What does lack of blood supply to the femoral head lead to?
avascular necrosis of femoral head
What does avascular necrosis of the femoral head lead to?
arthritis and maybe hip replacement
What does DDH stand for?
developmental dysplasia of the hip
When does DDH occur?
from birth - congenital problem
What are the severities of DDH?
- sublaxation
- Low dislocation
- high dislocation
What happens in DDH?
- ligament has laxity - becomes too loose
- causes head of the femur to slide out of acetabulum
What problems for the child can DDH cause?
- trouble walking - walking with a limp
What happens if femoral head and acetabulum are not in contact earlier on in DDH?
the femoral head will not develop properly
What are the possible hip joint movements?
- flexion/extension
- adduction/ abduction
- external/internal rotation
What forms the hip joint?
the acetabulum and femoral head