HIP JOINT Flashcards
Hip joint classification
- synovial, multiaxial,
ball-and-socket
Articular surfaces of the Hip joint
- Head of femur
- Acetabulum of hip bone
(innominate)
Structure of the Head of the Femur
- “ball”, covered in articular cartilage in all areas EXCEPT the fovea capitis
What are the 2 areas of the Acetabulum?
1. semilunar area (lunate surface):
- covered w articular cartliage
2. acetabular fossa:
- non-articular area
Structure of the Lunate Surface
- covered with articular cartilage (hayline)
Function of the Lunate Surface
- ⬇️ friction
What is the Acetabular notch bridges by?
- bridged by transverse ligament of the acetabulum
Structure of the Acetabular Labrum
- fibrocartilaginous wedge attached around acetabular rim
Function of the Acetabular Labrum
- deepens the acetabulum
→ increases stability
Structure of Acetabular Fossa
- X articular area
Function of Acetabular Fossa
- attach to ligamentum teres
Structure of the Acetabular Fat Pad
- w in acetabular fossa
- X articular
Function of the Acetabular Fat Pad
- store and secrete synovial fluid
- proprioception
Structure of the Articular Capsule
- outler layer: fibrous CT
- inner layer: syn membrane (loose CT- lubricates joint)
- capsular ligaments
- thickest ant + sup
Where is Synovial Membrane found in the hip joint?
- lines internal surface of articular
capsule and covers acetabular labrum
Hip joint movements - flexion and extension
- Flexion: 120°
- Extension: 20°
Hip joint movements - adduction + abduction
- Abduction: 45°
- Adduction: 45°
Hip joint movements - Medial/internal + lateral/external rotation
- Medial/internal rotation: 45°
- Lateral/external rotation: 45°
Capsular Ligaments in the Hip Joint
Iliofemoral lig - origin and insertion
anterior
- O: AIIS and acetabular rim
- I: intertrochanteric
line
Capsular Ligaments in the Hip Joint
Bands of the Iliofemoral ligament
anterior
- Superior band:
- ⬇️ ext, add
and ext rotation - Inferior band:
- ⬇️ ext and
ext rotation
Capsular Ligaments in the Hip Joint
Pubofemoral lig origin + insertion
anteroinferiorly
O: iliopubic eminence
I: lower part of
intertrochanteric line
* Blends with inferior band of
iliofemoral ligament
anteroinferiorly
Capsular Ligaments in the Hip Joint
Pubofemoral lig function
anteroinferiorly
- ⬇️ ext, abd,
and lat/ext rotation
anteroinferiorly
Capsular Ligaments in the Hip Joint
Ischiofemoral lig origin + insertion
posterior
- O: body of ischium
- I: neck + root of greater trochanter
posterior
Capsular Ligaments in the Hip Joint
Ischiofemoral lig function
- ⬇️ ext, abd,
and med rotation
Capsular Ligmanents
standing
extension
flexion
- Under moderate tension during standing
- Taut during extension
- Relaxed during flexion
Intracapsular ligaments
Transverse ligament of acetabulum origin
- O: bridges acetabular notch
Intracapsular ligaments
Ligamentum teres origin and insertion
enclosed in syn membrane
- O: acetabular notch and transverse ligament of acetabulum
- I: fovea capitis
enclosed in syn membrane
Intracapsular ligaments
Ligamentum teres function
- in adults = ?
- in children = has a small artery in early life that becomes obliterated in late childhood
Trochanteric Bursa - location
- bw greater
trochanter and iliotibial tract
Iliopectineal Bursa (aka iliposoas bursa) - location
- bw articular capsule
of hip joint and iliopsoas tendon
Structure and function of Bursae
- s: syniovial fluid-filled sac
- f: reduce friction / lubrication
Factors increasing stability at the hip joint
- head + socket = congruent
- acetabular labrum (deepens it)
- capsular ligaments (strengthens)
- muscles –> bring joint surfaces together
- angle of inclination:
- approx. 125°
- increases contact area of articular surfaces
Hip Joints Closed-Packed Position
extension
medial roation
abduction
