- 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;
- references:
- 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.
- Complications:
- Chondrolysis
- Coxarthrosis
- 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.
Isolated traumatic dislocation of the hip. Long-term results in 50 patients.
Posterior fracture dislocation of the hip with fractures of the femoral head.
Fate of bone grafts in acetabular roof reconstructions assessed by roentgenography and scintigraphy.
Hip Arthroscopy to Remove Loose Bodies After Traumatic Dislocation.