title: Biomechanical effect of posterolateral corner sectioning after ACL injury and reconstruction.
abstract: OBJECTIVE
  Posterolateral corner structures functionally interact with the ACL. The aim of this study was to investigate the capability of an isolated ACL reconstruction control laxity parameters in a knee with combined ACL and PLC and the increase in terms of laxity produced by the resection of the PC in an ACL-deficient knee.
  
  
  METHODS
  An in vitro cadaveric study was performed on seven knees. The joints were analysed in the following conditions: intact, after ACL resection, after popliteus complex resection, after ACL reconstruction and after LCL. Testing laxity parameters were recorded with an intra-operative navigation system and defined as: AP displacement at 30° and 90° of flexion (AP30 and AP90) applying a 130 N load and IE at 30° and 90° of knee flexion with a 5 N load.
  
  
  RESULTS
  Sectioning the ACL significantly increased the AP30 at 30° and 90° of knee flexion (p < 0.05). At 90° of knee flexion, the resection of the LCL determined a significant increase in terms of AP laxity (p < 0.05). At 90° has been found a significant difference for the IE laxity (p < 0.05) after PC resection. Sectioning the LCL produced a significant increase in IE laxity at 30° and 90° of knee flexion (p < 0.05).
  
  
  CONCLUSIONS
  Isolated ACL reconstruction is able to control the AP laxity with a combined complete lesion of the PLC at 30° of knee flexion, but not at higher angle of knee flexion. Considering the IE rotations, the reconstruction was not sufficient not even to control a partial lesion of the PLC. These findings suggest that additional surgical procedures should be considerate even when facing combined PLC lesion.
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. t.bonanzinga@gmail.com.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. t.bonanzinga@gmail.com.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Bonanzinga
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. c.signorelli@biomec.ior.it.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. c.signorelli@biomec.ior.it.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Signorelli
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. n.lopomo@biomec.ior.it.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. n.lopomo@biomec.ior.it.
authors.forename: Nicola
authors.initials: N
authors.lastname: Lopomo
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. alberto.grassi@ior.it.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. alberto.grassi@ior.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Grassi
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. mariapia.neri@ior.it.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. mariapia.neri@ior.it.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Neri
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. giuseppe@filardo.eu.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. giuseppe@filardo.eu.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Filardo
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. stefano.zaffagnini@unibo.it.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. stefano.zaffagnini@unibo.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zaffagnini
authors.affiliation: Clinica Ortopedica e Traumatologica II, Laboratorio di Biomeccanica ed Innovazione Tecnologica, Istituto Ortopedico Rizzoli, via di Barbiano, 1/10, 40136, Bologna, Italy. m.marcacci@biomec.ior.it.|Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, Alma Mater Studiorum, Bologna, Italy. m.marcacci@biomec.ior.it.
authors.forename: Maurilio
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D000369:Aged, 80 and over; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D008023:Ligaments, Articular / Q000601:surgery*; D016059:Range of Motion, Articular
keywords: ACL; Combined lesions; Kinematics; Laxity; Posterolateral corner