title: Current Concepts for Patellar Dislocation.
abstract: BACKGROUND
  Patellar dislocation usually occurs to the lateral side, leading to ruptures of the Medial Patellofemoral Ligament (MPFL) in about 90% of the cases. Even though several prognostic factors are identified for patellofemoral instability after patellar dislocation so far, the appropriate therapy remains a controversial issue.
  
  
  METHODS
  Authors searched the Medline library for studies on both surgical and conservative treatment for patellar dislocation and patellofemoral instability. Additionally, the reference list of each article was searched for additional studies.
  
  
  RESULTS
  A thorough analysis of the anatomical risk factors with a particular focus on patella alta, increased Tibial Tuberosity-Trochlear Groove (TT-TG) distance, trochlear dysplasia as well as torsional abnormalities should be performed early after the first dislocation to allow adequate patient counseling. Summarizing the results of all published randomized clinical trials and comparing surgical and conservative treatment after the first-time patellar dislocation until today indicated no significant evident difference for children, adolescents, and adults. Therefore, nonoperative treatment was indicated after a first-time patellar dislocation in the vast majority of patients.
  
  
  CONCLUSIONS
  Surgical treatment for patellar dislocation is indicated primarily in case of relevant concomitant injuries such as osteochondral fractures, and secondarily for recurrent dislocations.
authors.affiliation: Department of Trauma, Hannover Medical School, Hannover, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Petri
authors.affiliation: Department of Orthopaedic Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Ettinger
authors.affiliation: Department of Trauma, Hannover Medical School, Hannover, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Stuebig
authors.affiliation: Department of Trauma, Hannover Medical School, Hannover, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Brand
authors.affiliation: Department of Trauma, Hannover Medical School, Hannover, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.affiliation: Department of Orthopaedic Surgery, Agaplesion Ev. Hospital Bethel, Buckeburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Jagodzinski
authors.affiliation: Department of Trauma, Hannover Medical School, Hannover, Germany.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Omar
keywords: Evidence-Based Medicine; Knee; Medial Patellofemoral Ligament; Patella; Patellar Dislocation; Patellofemoral Instability