title: ACL Reconstruction Preserving the ACL Remnant Achieves Good Clinical Outcomes and Can Reduce Subsequent Graft Rupture.
abstract: BACKGROUND
  Although anterior cruciate ligament (ACL) reconstruction techniques that preserve remnant tissues have been described, complete preservation may be difficult, with little known about its clinical advantages.
  
  
  OBJECTIVE
  To compare clinical outcomes in patients undergoing ACL reconstruction with and without ACL remnant preservation.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Of 372 patients who underwent surgical treatment of an ACL injury between September 2006 and July 2010, 154 had no remaining identifiable ligament tissue and were excluded from this study. Attempts were made to preserve the ACL remnant as much as possible in the remaining 218 patients. These patients were divided into 2 groups: those in whom the remnant was preserved (group 1, n = 85) and those in whom the remnant was not preserved (group 2, n = 98). Patients were followed for at least 24 months. Outcomes, including graft rupture, were compared in the 2 groups.
  
  
  RESULTS
  Time from injury to surgery was significantly shorter (7.3 ± 16.3 vs 16.0 ± 30.3 months; P < .05) and the preinjury Tegner activity was significantly higher (7.6 ± 1.4 vs 7.1 ± 1.2; P < .05; 95% confidence interval, 1.2-13.7) in group 1 than in group 2. The postoperative negative ratio of the pivot-shift test was similar in the 2 groups (87% vs 81%). Anterior stability of the knee, as measured by a KT-2000 arthrometer, was significantly better in group 1 than in group 2 (1.0 ± 0.8 vs 1.3 ± 1.0 mm; P < .05). ACL graft rupture occurred in 1 patient (1.1%) in group 1 and in 7 patients (7.1%) in group 2 (P < .05). Regression analysis showed that preservation of the remnant decreased the likelihood of graft rupture (odds ratio, 11.2; 95% confidence interval, 1.2-101.7).
  
  
  CONCLUSIONS
  These findings confirmed that preserving the remnant tissue of the ACL may facilitate recovery of function and decrease graft rupture after primary reconstruction.
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Takazawa
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kawasaki
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Muneaki
authors.initials: M
authors.lastname: Ishijima
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Kubota
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Saita
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Kaneko
authors.affiliation: Juntendo University Nerima Hospital, Tokyo, Japan.
authors.forename: Sung-Gon
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Department of Orthopaedics, Juntendo Tokyo Metropolitan Koto Geriatric Medicine Center, Tokyo, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kurosawa
authors.affiliation: Department of Orthopaedics, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
keywords: anterior cruciate ligament reconstruction; hamstring autograft; prospective; reinjury; remnant preservation