title: Anterior cruciate ligament graft impingement against the posterior cruciate ligament: diagnosis using MRI plus three-dimensional reconstruction software.
abstract: OBJECTIVE
  The purpose of this study was to evaluate anterior cruciate ligament (ACL) impingement against the posterior cruciate ligament (PCL) with the knee in an extended position, which arthroscopy cannot detect.
  
  
  METHODS
  Ten normal knees and 30 ACL-reconstructed knees were assessed using MR imaging. The three-dimensional reconstruction of the ACL, PCL, femur and tibia were carried out using commercially available three-dimensional reconstruction software. Anterior cruciate ligament impingement against the PCL was graded into three categories: Grade 1, some space between the ligaments; Grade 2, no space between the ligaments, and the reconstructed ACL ran straight; and Grade 3, the reconstructed ACL did not run straight. The angle of the reconstructed ACL against the tibial plateau was also measured.
  
  
  RESULTS
  All normal knees were classified as Grade 1. The 30 reconstructed knees were classified as follows: Grade 1, 12 cases; Grade 2, 7 cases; and Grade 3, 11 cases. The mean angle of the Grade 3 reconstructed ACL knees was significantly more vertical against the tibia as compared with the Grade 1 knees (P<.05). The postoperative KT-2000 side-to-side difference of the Grade 3 knees (2.8+/-4.5 mm) was larger than that of the Grade 1 knees (0.2+/-1.7 mm) and Grade 2 knees (-0.6+/-2.2 mm), but no statistically significant difference could be detected between the three groups in the postoperative KT-2000 data.
  
  
  CONCLUSIONS
  This method is useful to evaluate ACL impingement against PCL, which cannot be detected by conventional arthroscopy during the operation. The surgeon should pay careful attention to the coronal angle of the reconstructed ACL.
authors.affiliation: Department of Orthopedic Surgery, Chugoku Rosai Hospital, Kure, Hiroshima, 737-0193, Japan. eisaku-fjm@umin.ac.jp
authors.forename: Eisaku
authors.initials: E
authors.lastname: Fujimoto
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Sumen
authors.forename: Masataka
authors.initials: M
authors.lastname: Deie
authors.forename: Masanori
authors.initials: M
authors.lastname: Yasumoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016119:Posterior Cruciate Ligament / Q000473:pathology*; D011183:Postoperative Complications / Q000175:diagnosis; D013710:Tendons / Q000637:transplantation