Vertical dislocation of the patella: report of 2 cases.

Vertical dislocation of the patella is rare and usually occurs as a result of blunt trauma. The patella rotates around a vertical axis. It can be diagnosed by its typical clinical features. This article presents a case of 2 patients with vertical dislocation who presented with high-impact injuries and had classic signs of a vertically dislocated patella. Unlike lateral patella dislocation, reduction under sedation is usually not possible. This is mainly due to increased tension within the quadriceps mechanism, which makes reduction difficult. The other factor that makes reduction difficult is that the patella could be wedged in the femoral condyles. Both patients underwent multiple unsuccessful attempts at reduction in the emergency department. These were later successfully reduced under general anesthesia and both patients went on to make an uneventful recovery. Multiple attempts without adequate relaxation could not only cause chondral damage but could also could endanger the extensor mechanism.