title: Single-bundle versus double-bundle anterior cruciate ligament reconstruction: A comparative study with propensity score matching.
abstract: BACKGROUND
  Numerous studies have elucidated the functional anatomy and biomechanics of the anterior cruciate ligament (ACL), as a result, double-bundle (DB) ACL reconstruction has received much attention and has become a popular choice because it gives better rotational stability. Many other studies, however, found no differences with respect to stability, and/or other clinical outcomes between the DB and single-bundle (SB) techniques. There is still not enough evidence as to whether the anatomical DB anterior cruciate ligament reconstruction (ACLR) is superior to anatomical SB reconstruction. The purpose of this study is to compare various clinical and functional outcomes between SB and DBACLR at 2 years followup.
  
  
  METHODS
  Medical records of patients with ACLR available for at least 2 years followup were reviewed retrospectively. 191 patients (164 males and 25 females) for SB and 48 patients (40 males and 8 females) for DB were selected using the inclusion and exclusion criteria. The mean age of SB and DB was 29.9 and 24.8 years, respectively. Propensity score (PS) was calculated based on age, sex and Tegner activity score and 48 patients in each group were matched by the PS. Lysholm score, International Knee Documentation Committee (IKDC) subjective knee score and Tegneractivity score were investigated. Functional performance tests, isokinetic muscle strength test with Biodex system, pivot shift test and KT-2000 arthrometer test were performed.
  
  
  RESULTS
  At 2 years followup, there were no significant differences between SB and DB group in Lysholm score (92.9 vs. 90.6,P= 0.224), IKDC subjective knee score (88.7 vs. 87.0,P= 0.524), Tegner activity score (7.3 vs. 8.0,P= 0.059). No significant differences were also found in all functional performance tests, isokinetic muscle strength tests in 60° and 180°/s, KT-2000 arthrometer test and pivot shift test (P> 0.05).
  
  
  CONCLUSIONS
  There were no significant differences of clinical and functional outcomes between SB and DB ACLR at 2 years followup.
authors.affiliation: Department of Orthopedic Surgery, College of Medicine, Seoul Paik Hospital, University of Inje, Seoul, Korea.
authors.forename: Jeong-Ku
authors.initials: JK
authors.lastname: Ha
authors.affiliation: Department of Orthopedic Surgery, Daejeon Military Hospital, Daejeon, Korea.
authors.forename: Dhong-Won
authors.initials: DW
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Konkuk University Medical Center, Seoul, Korea.
authors.forename: Jin-Goo
authors.initials: JG
authors.lastname: Kim
keywords: Anatomical reconstruction; Anterior cruciate ligament; anterior cruciate ligament reconstruction; double-bundle reconstruction; functional performance tests; knee joint; propensity score; sports medicine