Hip Dislocation

Question 1

ESSENCE

Answer 1

Condition where femoral head is pushed out of acetabulum

Question 2

EPIDEMIOLOGY

Anterior or posterior most common

Answer 2

90% are posterior dislocations

Question 3

AETIOLOGY

Most commonc causes

Answer 3

• Traumatic trauma (most common in adults - almost always)
• Developmental dysplasia of hip
• Cerebral palsy

Question 4

CLINICAL FEATURES

Presentation

Answer 4

• Severe pain and immobility in affected hip
  
  • May also have lower back, groin, thigh, knee or leg pain
• Deformity
• Pain with active or passive movement

Question 5

CLINICAL FEATURES

What deformity is present in anterior and posterior dislocation

Answer 5

Anterior - hip abducted, flexed and externally roated

Posterior - hip adducted, flexed and internally rotated (most common)

Question 6

INVESTIGATIONS

First choice

Answer 6

• X-ray - always indicated
• CT scan - suspicion for associated injuries such as fractures to surrounding structures

Question 7

What are x-ray findings in anterior and posterior dislocation

Answer 7

• Anterior
  
  • Femoral head larger than contralateral side and inferior to acetabulum
  • Femur appears abducted
  • External rotation of femur noted as lesser trochanter in full profile
• Posterior
  
  • Femoral head smaller than contralateral side and superior to acetabulum
  • Femur appears adducted
  • Internal rotation of femur noted as lesser trochanter poorly visualised

Question 8

MANAGEMENT

General principles

Answer 8

• Conservative
  
  • Closed reduction uncer conscious sedation
• Operative if above fails
  
  • Open reduction