title: Variability in ACL tunnel placement: observational clinical study of surgeon ACL tunnel variability.
abstract: BACKGROUND
  Multicenter and multisurgeon cohort studies on anterior cruciate ligament (ACL) reconstruction are becoming more common. Minimal information exists on intersurgeon and intrasurgeon variability in ACL tunnel placement. Purpose/
  
  
  OBJECTIVE
  The purpose of this study was to analyze intersurgeon and intrasurgeon variability in ACL tunnel placement in a series of The Multicenter Orthopaedic Outcomes Network (MOON) ACL reconstruction patients and in a clinical cohort of ACL reconstruction patients. The hypothesis was that there would be minimal variability between surgeons in ACL tunnel placement.
  
  
  METHODS
  Cross-sectional study; Level of evidence, 3.
  
  
  METHODS
  Seventy-eight patients who underwent ACL reconstruction by 8 surgeons had postoperative imaging with computed tomography, and ACL tunnel location and angulation were analyzed using 3-dimensional surface processing and measurement. Intersurgeon and intrasurgeon variability in ACL tunnel placement was analyzed.
  
  
  RESULTS
  For intersurgeon variability, the range in mean ACL femoral tunnel depth between surgeons was 22%. For femoral tunnel height, there was a 19% range. Tibial tunnel location from anterior to posterior on the plateau had a 16% range in mean results. There was only a small range of 4% for mean tibial tunnel location from the medial to lateral dimension. For intrasurgeon variability, femoral tunnel depth demonstrated the largest ranges, and tibial tunnel location from medial to lateral on the plateau demonstrated the least variability. Overall, surgeons were relatively consistent within their own cases. Using applied measurement criteria, 85% of femoral tunnels and 90% of tibial tunnels fell within applied literature-based guidelines. Ninety-one percent of the axes of the femoral tunnels fell within the boundaries of the femoral footprint.
  
  
  CONCLUSIONS
  The data demonstrate that surgeons performing ACL reconstructions are relatively consistent between each other. There is, however, variability of average tunnel placement up to 22% of mean condylar depth, likely reflecting the difference in individual surgeons' preferred tunnel locations. Individual surgeons are relatively consistent in their cases of ACL tunnels.
authors.affiliation: University of Iowa, Department of Orthopaedics and Rehabilitation, Iowa City, IA 52242, USA. brian-wolf@uiowa.edu
authors.forename: Brian R
authors.initials: BR
authors.lastname: Wolf
authors.forename: Austin J
authors.initials: AJ
authors.lastname: Ramme
authors.forename: Rick W
authors.initials: RW
authors.lastname: Wright
authors.forename: Robert H
authors.initials: RH
authors.lastname: Brophy
authors.forename: Eric C
authors.initials: EC
authors.lastname: McCarty
authors.forename: Armando R
authors.initials: AR
authors.lastname: Vidal
authors.forename: Richard D
authors.initials: RD
authors.lastname: Parker
authors.forename: Jack T
authors.initials: JT
authors.lastname: Andrish
authors.forename: Annunziato
authors.initials: A
authors.lastname: Amendola
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D013977:Tibia / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
keywords: CT imaging; anterior cruciate ligament reconstruction; intersurgeon; intrasurgeon; tunnel placement variability