title: Efficacy of magnetic resonance imaging evaluation for meniscal tear in acute anterior cruciate ligament injuries.
abstract: OBJECTIVE
  The objective of this study was to compare the preoperative magnetic resonance imaging (MRI) diagnostic rates of meniscal injuries combined with acute anterior cruciate ligament (ACL) injuries, as well as traumatic meniscal injuries without ACL injuries.
  
  
  METHODS
  From January 2005 through April 2013, 208 patients who underwent ACL reconstruction and 1,334 patients with traumatic meniscal tear injuries were examined by MRI and arthroscopy. Patients with chronic ACL injuries, revisions, fracture histories, or multiple-ligament injuries and patients with Outerbridge degenerative changes of grade 3 or greater were excluded, yielding 159 patients and 621 patients in the 2 groups, respectively. The medial meniscus (MM) and lateral meniscus (LM) examined by MRI and arthroscopy for findings of tears were compared in each group. The sensitivity, specificity, positive predictive value, and negative predictive value for MM and LM tears by MRI were compared and analyzed statistically.
  
  
  RESULTS
  The diagnostic sensitivity of MRI in the group with ACL injury was significantly lower than that in the ACL-intact group for the MM (P < .001) and LM (P = .040). The negative predictive value was also lower in the group with ACL injury for both the MM (P = .008) and LM (P < .001). There was no statistical difference in specificity and positive predictive value between the 2 groups.
  
  
  CONCLUSIONS
  This study showed that if a patient had an acute ACL tear, the sensitivity and negative predictive value of MRI for a meniscal tear were less than if there was no ACL tear, which led to the low diagnostic accuracy of MRI.
  
  
  METHODS
  Level III, retrospective case-control study.
authors.affiliation: Department of Orthopedic Surgery, Nanoori Seoul Hospital, Seoul, South Korea.
authors.forename: Tae-Seok
authors.initials: TS
authors.lastname: Nam
authors.affiliation: Department of Orthopedic Surgery, Dongguk University Ilsan Hospital, Goyang, South Korea.
authors.forename: Min Kyu
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Dongguk University Ilsan Hospital, Goyang, South Korea. Electronic address: drsky71@duih.org.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Ahn
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D001182:Arthroscopy; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000070600:Tibial Meniscus Injuries; D016896:Treatment Outcome; D055815:Young Adult