title: The Effect of Different Sagittal Angles of the Tibial Guide on Aperture Widening of the Tibial Tunnel during Modified Transtibial Anterior Cruciate Ligament Reconstruction: A RandomizedIn VivoStudy.
abstract: OBJECTIVE
  The effect of sagittal plane angle of the tibial tunnel on the severity of tibial intra-articular aperture expansion caused by iatrogenic re-reaming in anterior cruciate ligament (ACL) reconstruction using a modified transtibial technique is unknown. The purpose of this study was to compare the severity of intra-articular aperture widening at different angles (40°, 45°, and 50°) of the tibial guide (TG).
  
  
  METHODS
  Ninety-seven patients who underwent modified transtibial ACL reconstruction were randomly allocated to TG 40°, 45°, and 50° groups. Intra-articular tibial aperture width (TW) and tibial tunnel length (TTL) were measured intraoperatively using an arthroscopic ruler and a depth gauge.
  
  
  RESULTS
  The TG 50° group had significantly greater tibial aperture widening than the TG 40° group. There was a significant difference among TG 40°, 45°, and 50° groups and the percentage of knees with TTL <35 mm was 8%, 9% and 3%, respectively. There were 2 females with TTL <35 mm in TG 40° and 45° groups each. The average mediolateral length of the tibial plateau was 75 mm.
  
  
  CONCLUSIONS
  This study shows that the TG angle of 40° would reduce the severity of intra-articular aperture widening of the tibial tunnel compared to 45° or 50° in modified transtibial ACL reconstruction.
authors.affiliation: Department of Orthopedic Surgery, Inje University Ilsan Paik Hospital, Goyang, Korea.
authors.forename: Young Chan
authors.initials: YC
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, Mahidol University, Ramathibodi Hospital, Bangkok, Thailand.
authors.forename: Tulyapruek
authors.initials: T
authors.lastname: Tawonsawatruk
authors.affiliation: Department of Orthopedic Surgery, Inje University Ilsan Paik Hospital, Goyang, Korea.
authors.forename: Hyeong Hwa
authors.initials: HH
authors.lastname: Woon
authors.affiliation: Department of Orthopedic Surgery, Inje University Ilsan Paik Hospital, Goyang, Korea.
authors.forename: Ji Woong
authors.initials: JW
authors.lastname: Yum
authors.affiliation: Department of Orthopedic Surgery, Inje University Ilsan Paik Hospital, Goyang, Korea.
authors.forename: Myung Jin
authors.initials: MJ
authors.lastname: Shin
authors.affiliation: Department of Orthopedic Surgery, Far North Luzon General Hospital & Training Center, Luna, Philippines.
authors.forename: Rodolfo S
authors.initials: RS
authors.lastname: Bravo
authors.affiliation: Department of Orthopedic Surgery, Inje University Ilsan Paik Hospital, Goyang, Korea.
authors.forename: Kyung Wook
authors.initials: KW
authors.lastname: Nha
keywords: Anterior cruciate ligament; Aperture widening; Knee; Reconstruction; Tibial tunnel