title: Indications requiring preoperative magnetic resonance imaging before knee arthroscopy.
abstract: BACKGROUND
  Knee arthroscopy knee is gold standard in diagnosis and simultaneous treatment of knee disorders. But most patients undergo magnetic resonance imaging (MRI) before arthroscopy, although MRI results are not always consistent with arthroscopic findings. This raises the question in which suspected diagnoses MRI really has influence on diagnosis and consecutive surgical therapy.
  
  
  METHODS
  Preoperative MRI of 330 patients with knee disorders were compared with arthroscopic findings. The MRI were performed by 23 radiologists without specialization in musculoskeletal diagnostics. Specificity, sensitivity, negative/positive predictive value and accuracy of MRI were calculated in comparison to arthroscopic findings.
  
  
  RESULTS
  We found sensitivity/specificity of 58%/93% for anterior horn, 94%/46% for posterior horn of medial meniscus and 71%/81% for anterior and 62%/82% for posterior horn of lateral meniscus. Related to anterior cruciate ligament injuries we showed sensitivity/specificity of 82%/91% for grade 0 + I and 72%/96% for grade II + III. For Cartilage damage sensitivity/specificity of 98%/7% for grade I-, 89%/29% for grade II-, 96%/38% for grade III- and 96%/69% for grade IV-lesions were revealed.
  
  
  CONCLUSIONS
  The MRI should not be used as routine diagnostic tool for knee pain. No relevant information for meniscal lesions and anterior cruciate ligament ruptures has been gained with MRI from non-specialized outside imaging centres. The MRI should not be used as routine diagnostic tool for knee pain. No relevant information for meniscal lesions and anterior cruciate ligament ruptures has been gained with MRI from non-specialized outside imaging centres.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU), Munich, Germany.
authors.forename: Björn Peter
authors.initials: BP
authors.lastname: Roßbach
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU), Munich, Germany.
authors.forename: Matthias Frank
authors.initials: MF
authors.lastname: Pietschmann
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU), Munich, Germany.
authors.forename: Mehmet Fatih
authors.initials: MF
authors.lastname: Gülecyüz
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU), Munich, Germany.
authors.forename: Thomas Richard
authors.initials: TR
authors.lastname: Niethammer
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU), Munich, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Ficklscherer
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, Academic Hospital of Munich, Klinikum Augsburg, Augsburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wild
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU), Munich, Germany.
authors.forename: Volkmar
authors.initials: V
authors.lastname: Jansson
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Munich (LMU), Munich, Germany.
authors.forename: Peter Ernst
authors.initials: PE
authors.lastname: Müller
keywords: arthroscopy; diagnostic tool; knee; magnetic resonance imaging; sensitivity; specificity