Pelvis and Hip Joint Flashcards
Which 3 bones make up the pelvic girdle?
- L & R hip bones
- Sacrum
Which 3 joints does the pelvic girdle contain?
- 2 sacroiliac joints
- Pubic symphysis
Which bony features does the pelvic girdle connect?
The vertebral column to the femurs.
What is the function of the pelvis?
-stability, locomotion, protection
How is the pelvis positioned in the body?
Tilted forward slightly
What is another name for the hip bone?
Innominate bone
Which 3 bones fuse to form the innominate (hip) bone?
- Ilium
- Ischium
- Pubic
What is the area called where the 3 parts (ilium, ischium, pubis) of the pelvis fuse?
The acetabulum.
What is the acetabulum?
The ‘socket’ of the innominate bone that articulates with the femoral head»_space; hip joint.
What type of joint is the hip joint?
Ball and socket synovial joint.
What structures are involved in the hip joint?
- Head of femur
- Acetabulum (of innominate bone)
What structures provide stability in the hip joint? (3)
- Acetabulum
- Fibrous capsule
- Ligaments
What shape is the articular surface of the acetabulum?
Crescent-shaped (‘lunate’).
Where is the acetabulum deficient and what does this form?
Inferiorly»_space; acetabular notch.
What is the acetabular notch bridged by?
Transverse acetabular ligament.
What is the acetabular labrum?
Rim of cartilage than deepens the articular surface.
What is the proximal attachment of the fibrous capsule of the hip joint?
Rim of acetabulum.
What is the distal attachment of the fibrous capsule of the hip joint?
Femoral neck
- intertrochanteric line & greater trochanter
What are the main 3 ligaments that strengthen the hip joint?
- Iliofemoral
- Pubofemoral
- Ischiofemoral
What do these ligaments attach to distally?
The femur.
Which is the strongest ligament at the hip joint?
Iliofemoral ligament.
Which is the weakest ligament at the hip joint?
Ischiofemoral ligament.
Where does the iliofemoral ligament cover the hip joint?
Superiorly & anteriorly.
What is the function of the iliofemoral ligament?
Prevents hyperextension when standing.
Where does the pubofemoral ligament cover the hip joint?
Inferiorly & anteriorly.
What is the function of the pubofemoral ligament?
Prevents excessive abduction.
Where does the ischiofemoral ligament cover the hip joint?
Posteriorly.
What causes a pubic rami fracture?
Force from lateral direction.
How are pubic rami fractures treated?
Conservatively (i.e. pain relief).
What causes an ‘open book’ pelvic fracture?
Straight on force.
-e.g. motorbike crash
Why can pelvic fractures be problematic?
Pelvis holds 2-3 litres of blood»_space; internal bleeding.
Why are fractures to the neck of the femur common?
Neck of the femur is relatively thin.
What causes a posterior dislocation of the femur?
Impact when hip is flexed, internally rotated and adducted (seated position).
-e.g. car accident
What would a posterior dislocation look like?
Leg would appear shortened & internally rotated.
What other injuries may be associated with posterior dislocation of the femur? (2)
- Sciatic nerve injury
- Acetabular fracture
What causes an anterior dislocation of the femur?
Force during extreme abduction & external rotation of the hip.
What would an anterior dislocation of the femur look like?
Limb would appear externally rotated, abducted & flexed.
What structures are at risk in an anterior dislocation of the femur? (3)
Femoral artery, vein & nerve.
-they are all anterior
What may cause a medial dislocation/acetabular fracture?
Fall from a height.
What complication are associated with medial dislocation/acetabular fracture?
- Punctured bladder
- Urethral injury
- Punctured veins
- could be fatal (» bleeding into pelvis)
What may occur if the blood supply to femoral head is disrupted?
Avascular necrosis.
What can avascular necrosis of the femoral head lead to?
- Arthritis
- Joint replacements
What is Developmental Dysplasia of the Hip (DDH)?
A congenital abnormality
- ligaments around the hip joint are loose
- ball not centred in socket
- > > sublaxation or dislocation
What are possible movements of the hip?
- Flexion/extension
- Abduction/adduction
- External/internal rotation
