title: Anatomic double-bundle and over-the-top single-bundle with additional extra-articular tenodesis: an in vivo quantitative assessment of knee laxity in two different ACL reconstructions.
abstract: OBJECTIVE
  Combinations of intra- and extra-articular procedures have been proposed for anterior cruciate ligament reconstruction with the aim of achieving an optimal control of translational and rotational knee laxities. Recently, the need for better reproducing the structural and functional behavior of the native anterior cruciate ligament led to the definition of anatomic double-bundle surgical approach. This study aimed to quantitatively verify whether the in vivo static and dynamic behavior obtained using over-the-top single-bundle with extra-articular tenodesis reconstruction was comparable to the results achieved by anatomic double-bundle approach.
  
  
  METHODS
  Thirty-five consecutive patients, with an isolated anterior cruciate ligament injury, were included in the study. Standard clinical laxities and pivot-shift test were quantified before and after anterior cruciate ligament reconstruction by means of a surgical navigation system dedicated to kinematic assessment; displacements of medial and lateral compartment during stress tests were also analyzed.
  
  
  RESULTS
  Single-bundle with extra-articular tenodesis approach presented statistically better laxity reduction in varus/valgus stress test at full extension and in internal/external rotation at 90° of flexion; lateral plasty controlled better the lateral compartment during drawer test and varus/valgus stress test both at 0° and 30° of flexion and both the compartments during internal/external rotation at 90° of flexion. On the other hand, pivot-shift phenomenon was better controlled by anatomic double-bundle reconstruction.
  
  
  CONCLUSIONS
  Both the reconstructions worked similarly for static knee laxity. The extra-articular procedure played an important role in better constraining the displacement of lateral tibial compartment, whereas the anatomic double-bundle reconstruction better restored the dynamic behavior of knee joint highlighted under pivot-shift stress test.
  
  
  METHODS
  Case series.
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136, Bologna, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Zaffagnini
authors.forename: C
authors.initials: C
authors.lastname: Signorelli
authors.forename: N
authors.initials: N
authors.lastname: Lopomo
authors.forename: T
authors.initials: T
authors.lastname: Bonanzinga
authors.forename: G M
authors.initials: GM
authors.lastname: Marcheggiani Muccioli
authors.forename: S
authors.initials: S
authors.lastname: Bignozzi
authors.forename: A
authors.initials: A
authors.lastname: Visani
authors.forename: M
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000601:surgery*; D007718:Knee Injuries / Q000150:complications / Q000601:surgery*; D053656:Tenodesis / Q000379:methods*; D016896:Treatment Outcome