title: The influence of hamstring autograft size on patient-reported outcomes and risk of revision after anterior cruciate ligament reconstruction: a Multicenter Orthopaedic Outcomes Network (MOON) Cohort Study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of graft size on patient-reported outcomes and revision risk after anterior cruciate ligament (ACL) reconstruction.
  
  
  METHODS
  A retrospective chart review of prospectively collected cohort data was performed, and 263 of 320 consecutive patients (82.2%) undergoing primary ACL reconstruction with hamstring autograft were evaluated. We recorded graft size; femoral tunnel drilling technique; patient age, sex, and body mass index at the time of ACL reconstruction; Knee Injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee score preoperatively and at 2 years postoperatively; and whether each patient underwent revision ACL reconstruction during the 2-year follow-up period. Revision was used as a marker for graft failure. The relation between graft size and patient-reported outcomes was determined by multiple linear regression. The relation between graft size and risk of revision was determined by dichotomizing graft size at 8 mm and stratifying by age.
  
  
  RESULTS
  After we controlled for age, sex, operative side, surgeon, body mass index, graft choice, and femoral tunnel drilling technique, a 1-mm increase in graft size was noted to correlate with a 3.3-point increase in the KOOS pain subscale (P = .003), a 2.0-point increase in the KOOS activities of daily living subscale (P = .034), a 5.2-point increase in the KOOS sport/recreation function subscale (P = .004), and a 3.4-point increase in the subjective International Knee Documentation Committee score (P = .026). Revision was required in 0 of 64 patients (0.0%) with grafts greater than 8 mm in diameter and 14 of 199 patients (7.0%) with grafts 8 mm in diameter or smaller (P = .037). Among patients aged 18 years or younger, revision was required in 0 of 14 patients (0.0%) with grafts greater than 8 mm in diameter and 13 of 71 patients (18.3%) with grafts 8 mm in diameter or smaller.
  
  
  CONCLUSIONS
  Smaller hamstring autograft size is a predictor of poorer KOOS sport/recreation function 2 years after primary ACL reconstruction. A larger sample size is required to confirm the relation between graft size and risk of revision ACL reconstruction.
  
  
  METHODS
  Level III, retrospective comparative study.
authors.affiliation: OSU Sports Medicine, Sports Health and Performance Institute, Department of Orthopaedics, The Ohio State University, Columbus, Ohio, U.S.A.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Mariscalco
authors.forename: David C
authors.initials: DC
authors.lastname: Flanigan
authors.forename: Joshua
authors.initials: J
authors.lastname: Mitchell
authors.forename: Angela D
authors.initials: AD
authors.lastname: Pedroza
authors.forename: Morgan H
authors.initials: MH
authors.lastname: Jones
authors.forename: Jack T
authors.initials: JT
authors.lastname: Andrish
authors.forename: Richard D
authors.initials: RD
authors.lastname: Parker
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Kaeding
authors.forename: Robert A
authors.initials: RA
authors.lastname: Magnussen
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D064592:Autografts / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology / Q000601:surgery; D007718:Knee Injuries / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000637:transplantation*; D012086:Reoperation; D012189:Retrospective Studies; D014182:Transplantation, Autologous; D016896:Treatment Outcome; D055815:Young Adult