title: Horizontal intra-articular patellar dislocation resulting in quadriceps avulsion and medial patellofemoral ligament tear: a case report.
abstract: 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.
authors: Department of Orthopaedic Surgery, Division of Sports Medicine, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA. Dennis.kramer@childrens.harvard.edu
authors: Dennis E
authors: DE
authors: Kramer
authors: Michael K
authors: MK
authors: Simoni
mesh_terms: D000293:Adolescent; D006801:Humans; D008297:Male; D031222:Patellar Dislocation / Q000150:complications* / Q000601:surgery; D057071:Patellofemoral Joint / Q000293:injuries*; D052097:Quadriceps Muscle / Q000293:injuries*