Hip Injury

Description

• Hip injury includes hip fractures and dislocations of the proximal femur due to minor or major trauma, or overuse
• Hip fracture: Fracture of proximal femur. Classified as intracapsular or extracapsular
  • Intracapsular fracture: Femoral head or neck; often associated with disruption of femoral neck vessels; significant morbidity due to AVN and higher rate of malunion:
    • Femoral head fracture: Usually associated with hip dislocation (anterior > posterior)
    • Femoral neck fracture: Usually older adults with minor trauma, or young patient with major trauma. Patient may or may not be ambulatory. Often site of stress fracture in runners
  • Extracapsular fractures: Below acetabular capsule to the distal lesser trochanter. Normally do not disrupt blood flow. Morbidity typically due to patient immobilization, DVT, PE:
    • Trochanteric fractures: Greater trochanter usually fractured by avulsion at the site of insertion of the gluteus medius. Lesser trochanter usually fractured by avulsion from forceful contraction of iliopsoas; seen in young athletes and children
    • Intertrochanteric fracture: In line between greater and lesser trochanters. Common in elderly and osteoporotic patients secondary to fall. External rotation and shortening. Can be stable or unstable. Nonambulatory
    • Subtrochanteric fracture: Usually due to direct, major trauma in younger patients or lesser trauma in elderly. Common site of pathologic fracture. Can result in significant blood loss and shock
• Hip dislocation: Disarticulation of femoral head. Classified as posterior, anterior, and central:
  • Posterior dislocation (most common):
    • Often from motor vehicle accident (MVA) in which knees strike dashboard
    • 10% associated with sciatic nerve injury
  • Anterior dislocation:
    • Often due to trauma with sudden abduction of thigh
    • Associated femoral head fractures, femoral nerve injury
    • Can be anterior superior or anterior inferior
  • Central dislocation with acetabular fracture:
    • Usually from direct impact to greater trochanter
    • Associated with significant blood loss, sciatic nerve injury

• Hip dislocation: Uncommon; often spontaneously reduced at time of injury. Concern for tissue trapped in joint space:
  • Trivial force required for posterior hip dislocations in children <10 yr old
• Proximal femoral physeal fracture: Fracture at growth plate; high risk for osseous necrosis
• Slipped capital femoral epiphysis: Displacement between the femoral neck and capital femoral epiphysis. Typically in obese children
• Femoral neck fractures: Relatively common; stress fractures in young athletes
• Intertrochanteric fractures: Rare
• Consider pathologic fracture with minor trauma

Etiology

See individual injuries above