title: Graft size after anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The native anterior cruciate ligament (ACL) is composed of two distinct bundles, the anteromedial (AM) and posterolateral (PL), and both have been shown to be reliably measured on magnetic resonance imaging (MRI). The purpose of this study was to measure the size of the AM and PL bundles after ACL double-bundle reconstructions on MRI and compare this to the relative graft size at the time of surgery.
  
  
  METHODS
  Between January 2007 and April 2010, 85 knees were identified after allograft double-bundle ACL reconstruction with post-operative MRI (1.5 T) and met inclusion criteria. On standard sagittal, coronal and oblique coronal MRIs, the AM and PL bundles were delineated and the midsubstance width of the ACL graft was measured. The images were independently measured in a blinded fashion by two observers. Linear and curvilinear regression analysis was used to analyse the relationship between graft size and time after reconstruction.
  
  
  RESULTS
  The mean age of the patients was 24.6 years (SD 10.4). Mean time from surgery to post-operative MRI was 271.5 days (SD 183.4). The mean percentage of the original size of the AM bundle was 86.9% (SD 9.9) and of the PL bundle was 88.6% (SD 9.9). There was no correlation between the relative size of the AM graft and the time from surgery (r = 0.3, n.s.) and no significant relationship for the PL graft (r = 0.1, n.s).
  
  
  CONCLUSIONS
  On average, there was no graft enlargement of the AM and PL grafts 275.1 days after allograft ACL double-bundle reconstruction, as the mean relative graft size was less than 100 % on MRI. This study suggests that surgeons, who use allografts, should measure the ACL and replace it with a similar size, as there is a low risk of hypertrophy of the graft within one year post-operative.
  
  
  METHODS
  IV.
authors.affiliation: Department for Orthopaedic Surgery, University of Pittsburgh Medical Center, 3471 Fifth Avenue, Suite 1011, Pittsburgh, PA, 15213, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hensler
authors.forename: Motoko
authors.initials: M
authors.lastname: Miyawaki
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Illingworth
authors.forename: Carola F
authors.initials: CF
authors.lastname: van Eck
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000293:Adolescent; D000328:Adult; D064591:Allografts; D016118:Anterior Cruciate Ligament / Q000473:pathology* / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D006801:Humans; D006984:Hypertrophy; D007718:Knee Injuries / Q000175:diagnosis* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D011184:Postoperative Period; D019737:Transplants; D055815:Young Adult