Mechanism of Dislocation
A lateral force directly impacting the greater trochanter region can displace the femoral head horizontally inward, penetrating the medial wall of the acetabulum into the pelvic cavity. If the lower limb is in a slightly adducted position during injury, the femoral head may shift posteriorly, resulting in a fracture of the posterior acetabulum. Conversely, if the limb is in a mildly abducted and externally rotated position, the femoral head moves superiorly, causing a burst-type comminuted fracture of the acetabulum. In this scenario, all regions of the acetabulum sustain damage.
Clinical Presentation and Diagnosis
Central hip dislocation is generally caused by high-energy trauma, most often resulting from traffic accidents or falls from height.
Significant bleeding frequently occurs in the retroperitoneal space, which may lead to hemorrhagic shock.
Swelling, pain, and impaired mobility of the hip are observed, with a large hematoma often present on the lateral side of the upper thigh. The extent of limb shortening depends on the degree of femoral head impaction.
Cases of concurrent abdominal organ injury are not uncommon.
X-ray imaging can clearly identify the injury, while three-dimensional CT scans can provide a detailed reconstruction of acetabular fractures.
Treatment
Central hip dislocation may result in hypovolemic shock and associated abdominal organ injuries, which require prompt management. Significant medial displacement of the femoral head may necessitate supracondylar femoral traction. However, this method often proves less effective. Early open reduction is needed based on the type of acetabular fracture, accompanied by fixation of the acetabular fracture.