title: Kinematics of ACL and anterolateral ligament. Part I: Combined lesion.
abstract: OBJECTIVE
  To quantify the influence of ALL lesions on static and dynamic laxity in ACL-deficient knee.
  
  
  METHODS
  The study was performed in 10 fresh-frozen knees. The joints were analysed in the following conditions: intact, ACL resection and ACL + ALL resection. Testing parameters were defined as: anterior displacement at 30° and 90° of flexion (AP30, AP90) applying a manual-maximum load; internal rotation at 30° and 90° of flexion (INT30, INT90) applying a 5 N m torque and internal rotation and acceleration during manual pivot-shift (PS) test. Kinematics was acquired by a navigation system; a testing rig and a torquemeter were used to control the limb position and the applied torque. Paired Student's t test was conducted to assess statistical difference, and significance was set at P < 0.05.
  
  
  RESULTS
  The ALL resection determined a significant increase in terms of internal rotation (INT30 P = 0.02, INT90 P = 0.03), while AP30 (P n.s) and AP90 (P n.s) were not affected. ALL resection produced a significant increase in terms of acceleration during PS test (P < 0.01), but no significant change in PS internal rotation was observed.
  
  
  CONCLUSIONS
  The ALL plays a significant role in controlling static internal rotation and acceleration during PS test. On the other hand, ALL resection did not produce any significant change in terms of anterior displacement. A trend was seen for the internal rotation during the pivot-shift test to increase after ALL resection was higher when compared to the intact and isolated ACL lesion states; however, the differences were not significant. The results highlight the clinical relevance of this structure that should be assessed before an ACL reconstruction in order to avoid residual laxity.
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, BO, Italy. t.bonanzinga@gmail.com.|Clinica Ortopedica e Traumatologica I, Istituto Ortopedico Rizzoli, Bologna, BO, Italy. t.bonanzinga@gmail.com.
authors.forename: T
authors.initials: T
authors.lastname: Bonanzinga
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, BO, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Signorelli
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, BO, Italy.|Clinica Ortopedica e Traumatologica I, Istituto Ortopedico Rizzoli, Bologna, BO, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Grassi
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, BO, Italy.|Dipartimento di Ingegneria dell'Informazione, Università degli Studi di Brescia, Brescia, BS, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Lopomo
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, BO, Italy.|Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, BO, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Bragonzoni
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, BO, Italy.|Clinica Ortopedica e Traumatologica I, Istituto Ortopedico Rizzoli, Bologna, BO, Italy.|Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, BO, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Zaffagnini
authors.affiliation: Laboratorio di Biomeccanica e Innovazione Tecnologica, Istituto Ortopedico Rizzoli, Via Di Barbiano 1/10, 40136, Bologna, BO, Italy.|Clinica Ortopedica e Traumatologica I, Istituto Ortopedico Rizzoli, Bologna, BO, Italy.|Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, BO, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D000368:Aged; D016118:Anterior Cruciate Ligament / Q000502:physiology* / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology; D001696:Biomechanical Phenomena / Q000502:physiology; D002102:Cadaver; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D007719:Knee Joint / Q000502:physiology*; D008023:Ligaments, Articular / Q000502:physiology* / Q000601:surgery; D013314:Stress, Mechanical
keywords: Anterolateral; Combined lesions; Laxity; Navigation system