Posterior Hip Dislocation

Question 1

What is the most common type of hip dislocation?

Answer 1

Posterior dislocation

Question 2

What position is a normal hip most vulnerable in?

Answer 2

Flexed and adducted position OR crossed legs
*force will be translated along the shaft of the femur
*can drive the humeral head posteriorly over the lip of the acetabulum
*femoral head escapes through a rent in the capsule

Question 3

What will be found on PE?

Answer 3

1. Patient lies with injured hip in flexion, adduction, and internal rotation
2. Limb appears shortened
3. Muscle spasm may be present
   *can cause problems with reduction

Question 4

What will be found on the radiographs

Answer 4

1. Femoral head lies above the acetabulum
2. Oblique view reveal the head is also posterior to the joint

Question 5

Is a posterior hip dislocation an emergency?

Answer 5

Yes
*the dislocation allows the torn capsule and surrounding structure to constrict the femoral neck vessels
*reduce ASAP
*>8 hours from injury can cause AVN

Question 6

How to reduce a posterior hip dislocation?

Answer 6

1. Apply upward traction on the flexed thigh in external rotation
2. Forward pressure on the femoral head from behind
3. Followed with immobilization in bed for 3 weeks in traction OR immobilize in a hip spica cast for 3 week in extension,abduction, and external rotation