RT Book, Section A1 Breed, Meghan A1 Fitch, Robert Warne A2 Knoop, Kevin J. A2 Stack, Lawrence B. A2 Storrow, Alan B. A2 Thurman, R. Jason SR Print(0) ID 1181042108 T1 Patellar Dislocations T2 The Atlas of Emergency Medicine, 5e YR 2021 FD 2021 PB McGraw-Hill PP New York, NY SN 9781260134940 LK accessmedicine.mhmedical.com/content.aspx?aid=1181042108 RD 2024/03/28 AB Patellar dislocations can result from either direct trauma or powerful quadriceps contraction with knee flexion. Commonly, the patella dislocates laterally. Patients who present after a patellar dislocation may state their knee dislocated and spontaneously reduced. A hemarthrosis can be present. Common complaints include pain, swelling, and deformity. The patellar apprehension test (gently displacing the patella laterally or medially while in extension) is often positive in spontaneously reduced patellar dislocations. The patient will become apprehensive as you attempt to reproduce the dislocation. Radiography will confirm the dislocation and help rule out associated fracture. Fractures of the patella or lateral femoral condyle occur in 5% of patients.