title: Prediction of chronicity of anterior cruciate ligament tear using MRI findings.
abstract: BACKGROUND
  The estimation of anterior cruciate ligament (ACL) tear is required in certain cases involving legal and financial administration, such as the worker's compensation and/or insurance. The aim of this study is to propose and evaluate a quantitative evaluation instrument to estimate the chronicity of the ACL tear, based on the four magnetic resonance imaging (MRI) findings.
  
  
  METHODS
  One hundred and fifty one cases of complete ACL tear confirmed by arthroscopy were divided into 4 groups according to the time from ACL injury to MRI acquisition: acute (< 6 weeks), subacute (6 weeks to 3 months), intermediate (3 months to 1 year), and chronic (> 1 year). The four MRI findings including ACL morphology, joint effusion, posterior cruciate ligament angle, and bone bruise were analyzed for temporal changes among the 4 groups. Binary logistic regression equations were formulated using the MRI findings to estimate the chronicity of ACL tear in a quantitative manner, and the accuracy of the formulated regression equations was evaluated.
  
  
  RESULTS
  The four MRI findings showed substantial temporal correlation with the time-limits of ACL injury to be included in the estimation model. Three predictive binary logistic equations estimated the probability of the ACL injury for the three cutoff time-limits of 6 weeks, 3 months, and 1 year with accuracies of 82.1%, 89.4%, and 89.4%, respectively.
  
  
  CONCLUSIONS
  A series of predictive logistic equations were formulated to estimate the chronicity of ACL tear using 4 MRI findings with chronological significance.
authors: Department of Orthopaedic Surgery, Kyungpook National University Hospital, Daegu, Korea.
authors: Jong Pil
authors: JP
authors: Yoon
authors: Jae Ho
authors: JH
authors: Yoo
authors: Chong Bum
authors: CB
authors: Chang
authors: Sung Ju
authors: SJ
authors: Kim
authors: Ja Young
authors: JY
authors: Choi
authors: Jae Hyuck
authors: JH
authors: Yi
authors: Tae Kyun
authors: TK
authors: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D002648:Child; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
keywords: Anterior cruciate ligament; Chronicity; Magnetic resonance imaging; Predictive model