- hip dislocations are typically caused by high-energy trauma, usually from motor-vehicle accidents.
- they occur most frequently in young patients;
- types of dislocations:
- anterior dislocation
- central acetabular fracture dislocations
- posterior hip - frx - dislocations
- associated injuries:
- ipsilateral knee injuries: cruciate ligament injuries in 25%, collateral ligament injuries in 21%, and
periarticular fracture in 15%.
- Clinical Findings:
- in general, patients w/ posterior hip dislocations will have internal rotation of the hip, where as
patients w/ anterior dislocations will have external rotation of the hip;
- if this is not the case, be suspicious for femoral neck or shaft frx, or an ipsilateral knee dislocation;
- Radiographic Evaluation of Hip Dislocation
- AP of the Hip;
- pelvic series radiographs (AP, inlet and outlet);
- acetabular series radiographs (Judet views);
- radiograph of the femur and knee;
- w/ posterior - frx - dislocations, the head will migrate superiorly;
- w/ anterior dislocations, the head will migrate inferiorly or medially;
- because trauma cassett is placed underneath buttocks, femoral head will appear small w/ posterior dislocations and
will appear large w/ anterior dislocations;
- Closed Reduction
- ensure that associated femoral neck fracture is not present;
- post reduction CT scan:
- look for concentric reduction and for the presence of intra-articular fragments or injury to the femoral
head and/or acetabulum
- CT is esp useful with associated posterior wall fracture (to help predict stability);
- note high incidence of false negatives with CT (can miss intra-articular fragments);
- with slight non concentric reduction or question of OCD fragments consider hip arthroscopy;
- Reduction of posterior dislocation of the hip in the prone position.
- Irreducible fracture-dislocation of the hip: a severe injury with a poor prognosis.
- Irreducible traumatic dislocations of the hip.
- Coxarthrosis Following Traumatic Posterior Dislocation of the Hip.
- Heterotopic Ossification
- AVN after Hip Dislocation:
- Sciatic Nerve Injury:
- approx 10% w/ dislocation but may be as high as 35% in posterior acetabular fracture;
- iatrogenic injury may be the result of laceration, penetration by drill bits, excessive traction by retractors, or prolonged
extension of the ipsilateral knee;
- it appears that injuries of peroneal division of sciatic nerve have a worse prognosis than injuries of the tibial division;
- peroneal division have less fascicles, larger in size, and protected by less connective tissue
- Coxa Magna
- may occur in upto 50% of children who sustain hip dislocation
Treatment of unreduced traumatic posterior dislocations of the hip.
Fractures of the femoral head.