Horizontal intra-articular patellar dislocation resulting in quadriceps avulsion and medial patellofemoral ligament tear: a case reportKramer, Dennis E.a; Simoni, Michael K.bJournal of Pediatric Orthopaedics B: July 2013 - Volume 22 - Issue 4 - p 329–332 doi: 10.1097/BPB.0b013e328357182b Femur & Knee Abstract Author Information Intra-articular patellar dislocations are rare. We present a 13-year-old boy who sustained a complete horizontal intra-articular patellar dislocation following blunt trauma to the flexed knee. Closed reduction was unsuccessful and open reduction indicated a repairable quadriceps avulsion and medial patellofemoral ligament tear. He is the youngest patient to sustain a quadriceps rupture and the only patient to sustain a medial patellofemoral ligament tear to date. His flexed knee and the horizontally positioned patella (seen on lateral radiograph) were indicative of a complete rotational injury with extensor mechanism involvement. Open reduction allowed for the repair of both injuries and a favorable outcome. aDepartment of Orthopaedic Surgery, Division of Sports Medicine, Children’s Hospital Boston bHarvard Medical School, Boston, Massachusetts, USA Correspondence to Dennis E. Kramer, MD, Department of Orthopaedic Surgery, Division of Sports Medicine, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA Tel: +1 617 355 2308; fax: +1 617 730 0456; e-mail: Dennis.email@example.com © 2013 by Lippincott Williams & Wilkins, Inc.