title: MR imaging of anterior cruciate ligament reconstruction graft.
abstract: OBJECTIVE
  The objective was to determine the MR imaging findings that differentiate intact anterior cruciate ligament reconstruction graft, partial-thickness tear, and full-thickness tear, using arthroscopy as the gold standard.
  
  
  METHODS
  Sixteen consecutive MR imaging examinations were retrospectively and independently evaluated by two musculoskeletal radiologists for primary signs (graft signal, orientation, fiber continuity, complete discontinuity, and thickness) and secondary signs (anterior tibial translation, uncovered posterior horn lateral meniscus, posterior cruciate ligament hyperbuckling, and abnormal posterior cruciate ligament line) of anterior cruciate ligament reconstruction graft tear in 15 patients with follow-up arthroscopy. Results were compared with arthroscopy, and both receiver operating characteristic curves and kappa values for interobserver variability were calculated.
  
  
  RESULTS
  Arthroscopy revealed four full-thickness graft tears, seven partial-thickness tears, and five intact grafts. Of the primary signs, graft fiber continuity in the coronal plane and 100% graft thickness in the sagittal or coronal plane were most valuable in excluding full-thickness tear. Complete discontinuous graft in the coronal plane also was valuable in diagnosis of full-thickness tear. Of the secondary signs, anterior tibial translation and uncovered posterior horn lateral meniscus assisted in differentiating graft tear (partial or full thickness) from intact graft. The other primary and secondary signs were less valuable. Kappa values were highest for graft fiber continuity and graft discontinuity in the coronal plane.
  
  
  CONCLUSIONS
  Full-thickness anterior cruciate ligament graft tear can be differentiated from partial-thickness tear or intact graft by evaluating for graft fiber continuity (coronal plane), complete graft discontinuity (coronal plane), and graft thickness (coronal or sagittal plane).
authors.affiliation: Department of Radiology, University of Michigan Medical Center, 1500 E. Medical Center Dr., TC-2910G, Ann Arbor, MI 48109-0326, USA.
authors.forename: L K
authors.initials: LK
authors.lastname: Horton
authors.forename: J A
authors.initials: JA
authors.lastname: Jacobson
authors.forename: J
authors.initials: J
authors.lastname: Lin
authors.forename: C W
authors.initials: CW
authors.lastname: Hayes
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis*; D019919:Prosthesis Implantation; D012008:Recurrence; D012680:Sensitivity and Specificity