title: Relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch: MRI and arthroscopy correlation.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch.
  
  
  METHODS
  We retrospectively reviewed the 105 patients with knee magnetic resonance imaging (MRI) with or without knee arthroscopy [group 1: patients with arthroscopic notchplasty (N = 47), group 2: knee arthroscopy demonstrating intact ACL (N = 33), and group 3: patients with normal knee MRI but no arthroscopy (N = 25)]. Groups 2 and 3 served as an arthroscopic and MR control group, respectively. Two musculoskeletal radiologists reviewed all MR examinations. The intercondylar notch width, notch index (width of intercondylar notch/width of femoral condyle), transverse notch angle (TNA), sagittal notch angle (SNA), and notch area were recorded on axial and sagittal MR images at the midpoint of Blumensaat's line which was identified on sagittal images. The diameter of the ACL was recorded on coronal MR images at the posterior end of Blumensaat's line.
  
  
  RESULTS
  The mean values of the intercondylar notch width, notch index, TNA, SNA, notch area, and ACL diameter for the three groups were 16.0 mm/0.2/50.3 degrees /36.5 degrees /249.0 mm(2)/7.7 mm (group 1); 19.3 mm/0.3/52.9 degrees /40.2 degrees /323.4 mm(2)/4.8 mm (group 2); and 20.3 mm/0.3/51.4 degrees /39.1 degrees /350.8 mm(2)/4.5 mm (group 3). The intercondylar notch width, notch index, SNA, and notch area were smaller, and ACL diameter was thicker in group 1 compared with the other groups (p < 0.05).
  
  
  CONCLUSIONS
  Patients with mucoid ACL hypertrophy show a narrower notch, a steeper notch angle, and a smaller notch area than control groups.
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Ji Hyeon
authors.initials: JH
authors.lastname: Cha
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Myung Jin
authors.initials: MJ
authors.lastname: Shin
authors.forename: Byeong Kyoo
authors.initials: BK
authors.lastname: Choi
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Bin
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016118:Anterior Cruciate Ligament / Q000473:pathology*; D001182:Arthroscopy; D006801:Humans; D006984:Hypertrophy; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D012189:Retrospective Studies