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
Structure of the Acetabulum in the hip joint
- “socket”, formed bye the fusion of 3 parts of the hip bone (innominate):
- ischium
- illium
- pubis
What are the 2 areas of the Acetabulum?
- semilunar area (lunate surface):
- covered w articular cartliage - acetabular fossa:
- non-articular area
Structure of the Acetabular notch in the hip joint
- inf deficiency of acetabular rim
- bridged by transverse ligament of the acetabulum
Structure of the Acetabular Labrum in the hip joint
- fibrocartilaginous wedge attached
around rim of acetabulum - Ends are joined across acetabular
notch by transverse ligament of
acetabulum
Function of the Acetabular Labrum in the hip joint
- deepens the acetabulum
→ increases stability
Location of the Acetabular Fat Pad in the hip joint
- acetabular fossa
Function of the Acetabular Fat Pad in the hip joint
- proprioception
Structure of the Articular Capsule in the hip joint
- v strong due to mult fibres running in diff directions
- reinforced by capsular ligaments
- thickest ant + sup
Origin of Articular Capsule in the hip joint
- prox attaches to the acetabular labrum, innominate bone, and transverse ligament at the acetabular notch
Insertion of Articular Capsule in the hip joint
- dist attaches to intertrochanteric line and neck of femur
Structure of Synovial Membrane in the hip joint
- lines internal surface of articular
capsule and covers acetabular labrum
Structure of the joint cavity in the hip joint
- communicates with iliopectineal (iliopsoas) bursa
Hip joint movements - flexion and extension
- in the sagittal plane, around horizontal/transverse axis
- Flexion: 120°
- Extension: 20°
Hip joint movements - adduction + abduction
- in coronal plane, around anteroposterior axis
- Abduction: 45°
- Adduction: 45°
Hip joint movements - Medial/internal + lateral/external rotation
- in transverse plane, around
longitudinal axis - Medial/internal rotation: 45°
- Lateral/external rotation: 45°
Capsular Ligaments in the Hip Joint - Iliofemoral ligament structure
- strong, thick ligament located anteriorly
- triangular in shape
Capsular Ligaments in the Hip Joint - Iliofemoral ligament origin and insertion
- O: AIIS and acetabular rim
- I: intertrochanteric
line
Bands of the Iliofemoral ligament
- Superior band:
- limits extension, adduction
and lateral/external rotation - Inferior band:
-limits extension and
lateral/external rotation
Capsular Ligaments in the Hip Joint - Pubofemoral ligament location
- located anteroinferiorly
Capsular Ligaments in the Hip Joint - Pubofemoral origin + insertion
O: iliopubic eminence (the elevated bony region found lat to the pectineal surface of the superior pubic ramus)
I: lower part of
intertrochanteric line
* Blends with inferior band of
iliofemoral ligament
Capsular Ligaments in the Hip Joint - Pubofemoral function
- limits extension, abduction
and lateral/external rotation
Capsular Ligaments in the Hip Joint - Ischiofemoral ligament structure
- Less defined than other
capsular ligaments - Located posteriorly –> spirals
superolaterally around capsule
Capsular Ligaments in the Hip Joint - Ischiofemoral ligament origin + insertion
- O: body of ischium
- I: neck + root of greater trochanter
Capsular Ligaments in the Hip Joint - Ischiofemoral ligament function
- limits extension, abduction
and medial/internal rotation
Function of Capsular Ligmanents
- Under moderate tension during standing
- Taut during extension
- Relaxed during flexion
Intracapsular ligaments -
1. Transverse ligament of acetabulum origin
- O: bridges acetabular notch
Intracapsular ligaments -
2. Ligamentum teres (aka ligament @ the head of the femur) origin and insertion
- O: acetabular notch and transverse ligament of acetabulum
- I: fovea capitis
Intracapsular ligaments -
2. Ligamentum teres (aka ligament @ the head of the femur) structure
- enclosed in a sleeve of synovial membrane → intracapsular, but extrasynovial
Intracapsular ligaments -
2. Ligamentum teres (aka ligament @ the head of the femur) function
- in adults = uncertain
- in children = has a small artery in early life that becomes obliterated in late childhood
Greater Trochanteric Bursa of the Hip Joint - location
- bw greater
trochanter and iliotibial tract
Iliopectineal Bursa (aka iliposoas bursa) of the Hip Joint - location
- bw articular capsule
of hip joint and iliopsoas tendon
Iliopectineal Bursa (aka iliposoas bursa) of the Hip Joint - function
- communicates with hip joint cavity
Structure and function of Bursae
- s: fluid-filled sac around a synovial joint
- f: reduce friction bw 2 structures @ a joint
Factors increasing stability at the hip joint
- articular fit (head + socket are congruent)
- acetabular labrum (wedge of fibrocartilage of acetabulum t/f deepens it)
- strong capsule –> reinforced by capsular ligaments
- muscles –> line of pull to bring joint surfaces together
- angle of inclination:
- angle between neck and shaft of femur
- approx. 125°
- increases contact area of articular surfaces
Hip Joints Closed-Packed Position
- articular surfaces have max contact w each other
- capsular ligaments are taut (have a spiral arrangement -> winding and tightening during extension)
- occurs during EXTENSION
= INCR stab
x3 Capsular Ligaments of the Hip joint
- ligament that are thickenings of the joint capsule itself and are going to reinforce that joint capsule
1. Iliofemoral ligament
2. Pubofemoral ligament
3. Ischiofemoral ligament
x2 Intracapsular Ligaments of the Hip joint
- ligaments found w in the joint capsule
1. Transverse Ligament of the Acetabulum
2. Ligamentum teres
