Hip Joint

Question 1

Articulating surfaces

Answer 1

Head of femur

Acetabulum of the pelvis

Question 2

Ligaments

Answer 2

Intracapsular…
- Ligament of head of femur

Extracapsular…

• Iliofemoral ligament
• Pubofemoral ligament
• Ischiofemoral ligament

Question 3

Neurovascular structures

Answer 3

Vascular supply - medial and lateral circumflex femoral arteries + artery to head of femur
Innervation - femoral nerve, obturator nerve, superior gluteal nerve, nerve to quadratus femoris

Question 4

Stabilising factors

Answer 4

Deep acetabulum
Acetabular labrum - fibrocartilaginous collar around acetabulum which increases the depth
Ligaments and thickened joint capsule (spiral orientation - become tighter when the joint is extended)

Question 5

Movements

Answer 5

Flexion 
Extension 
Abduction 
Adduction 
Medial/lateral rotation

Question 6

Fracture of neck of femur

Answer 6

40 years = falls
Lateral rotation of limb
Risk of avascular necrosis of the femoral head and neck

Question 7

Surgical hip replacement

Answer 7

A plastic socket is cemented to the hip bone in place of the acetabulum
Stainless steel femoral stem and head replaces the femur
Usually performed after traumatic injury/degenerative disease of the joint

Question 8

Dislocation of femoral head

Answer 8

• Congenital - 8x more likely in girls, femoral head not placed in acetabulum during development, shorter affected limb, inability to abduct at hip joint, +ve Trendelenburg, predisposes arthritis
• Acquired….
• Posterior - more common, femoral head forced backwards, tears through inferior and posterior joint capsule, limb shortened + medially rotated, can damage sciatic nerve causing paralysis of hamstrings and muscles distal to knee
• Anterior - rarer, consequence of extension, abduction + lateral rotation, femoral head ends up anterior and inferior to acetabulum, often pulls acetabular labrum with it