title: Anatomic single- versus double-bundle ACL reconstruction: a meta-analysis.
abstract: OBJECTIVE
  To determine whether anatomic double-bundle anterior cruciate ligament (ACL) reconstruction compared to anatomic single-bundle ACL reconstruction more effectively restored antero-posterior (A-P) laxity, rotatory laxity and reduced frequency of graft rupture. Our hypothesis was that anatomic double-bundle ACL reconstruction results in superior rotational knee laxity and fewer graft ruptures due to its double-bundle tension pattern, compared with anatomic single-bundle ACL reconstruction.
  
  
  METHODS
  An electronic search was performed using the PubMed, EMBASE and Cochrane Library databases. All therapeutic trials written in English reporting knee kinematic outcomes and graft rupture rates of primary anatomic double- versus single-bundle ACL reconstruction were included. Only clinical studies of levels I-II evidence were included. Data regarding kinematic tests were extracted and included pivot-shift test, Lachman test, anterior drawer test, KT-1000 measurements, A-P laxity measures using navigation and total internal-external (IRER) laxity measured using navigation, as well as graft failure frequency.
  
  
  RESULTS
  A total of 7,154 studies were identified of which 15 papers (8 randomized controlled trials and 7 prospective cohort studies, n = 970 patients) met the eligibility criteria. Anatomic ACL double-bundle reconstruction demonstrated less anterior laxity using KT-1000 arthrometer with a standard mean difference (SMD) = 0.36 (95% CI 0.214-0.513, p < 0.001) and less A-P laxity measured with navigation (SMD = 0.29 95% CI 0.01-0.565, p = 0.042). Anatomic double-bundle ACL reconstruction did not lead to significant improvements in pivot-shift test, Lachman test, anterior drawer test, total IRER or graft failure rates compared to anatomic single-bundle ACL reconstruction.
  
  
  CONCLUSIONS
  Anatomic double-bundle ACL reconstruction is superior to anatomic single-bundle reconstruction in terms of restoration of knee kinematics, primarily A-P laxity. Whether these improvements of laxity result in long-term improvement of clinical meaningful outcomes remains uncertain.
  
  
  METHODS
  II.
authors.affiliation: Department of Orthopaedics, Sahlgrenska University Hospital, 431 80, Mölndal, Sweden.
authors.forename: Neel
authors.initials: N
authors.lastname: Desai
authors.forename: Haukur
authors.initials: H
authors.lastname: Björnsson
authors.forename: Volker
authors.initials: V
authors.lastname: Musahl
authors.forename: Mohit
authors.initials: M
authors.lastname: Bhandari
authors.forename: Max
authors.initials: M
authors.lastname: Petzold
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
authors.forename: Kristian
authors.initials: K
authors.lastname: Samuelsson
mesh_terms: D016118:Anterior Cruciate Ligament / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*