injuries poisoning
Patellar Dislocations
Diagnosis of Patellar Dislocations
Clinical evaluation X-rays to exclude fracture A patellar dislocation, unless spontaneously reduced, is clinically obvious; ie, the patella is visibly and palpably displaced laterally, and the patient holds the knee in a slightly flexed position and is unwilling to straighten it. If the dislocation has spontaneously reduced, hemarthrosis is often present, and the peripatellar area is usually tender. Close-up comparing the normal right knee (left) and swollen left knee of a male patient following dislocation of the kneecap (patella) as a result of an injury. DR P. MARAZZI/SCIENCE PHOTO LIBRARY This anteroposterior view of the knee shows a patellar dislocation, characterized by extreme lateral displacement of the patella, outside its normal location between the femoral condyles. Image courtesy of Danielle Campagne, MD. Anteroposterior and lateral knee x-rays and patellar views are taken to exclude fracture, even if the dislocation has obviously reduced. 