title: Infrared assessment of knee instability in ACL deficient patients.
abstract: OBJECTIVE
  Previous clinical studies have shown that anterior cruciate ligament (ACL) ruptures require reconstructive surgery. The main goal of this study is an objective test definition for unstable knee diagnosis based on real measurements by using infrared cameras and adequate software.
  
  
  METHODS
  In the study of gait analysis 35 males with deficient ACL's participated. Pathological parameters for anterior posterior translation (APT) and internal external rotation (IER) and their values of kinematic data were obtained from a gait analysis 3D system. Movement curves were obtained by recording the position of fluorescent markers over time. A machine learning algorithm was developed in order to support decisions on the severity of the ACL injury and its corresponding deficiency. The algorithm was based on logistic regression.
  
  
  RESULTS
  The value of APT, designated as exponentiation of the Ө coefficient (Exp (Ө)) of APT, showed that the likelihood of ACL-deficient knee occurrence due to higher values of APT is 1.1758 (95 % CI) times more frequent than that of the patients with lower values of APT. The value of IER, designated as Exp (Ө) of IER, showed that the patients with higher values of IER present 2.2516 (95 % CI) times higher values of ACL-deficient knee frequency than those with lower values.
  
  
  CONCLUSIONS
  This study showed that the creation of ordered pairs of pathological parameters gives a wider picture of ACL deficiency and that such an algorithm may improve both examination and treatment of patients.
authors.affiliation: Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovica 69, Kragujevac, Serbia. maticaleksandar@gmail.com.|Clinical Centre of Kragujevac, Clinic for Orthopaedics and Traumatology, Zmaj Jovina 30, Kragujevac, Serbia. maticaleksandar@gmail.com.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Matić
authors.affiliation: Faculty of Engineering, University of Kragujevac, Sestre Janjica 6, Kragujevac, Serbia. petrovic.suzana@gmail.com.
authors.forename: Suzana
authors.initials: S
authors.lastname: Petrović Savić
authors.affiliation: Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovica 69, Kragujevac, Serbia. branko.ristic@gmail.com.|Clinical Centre of Kragujevac, Clinic for Orthopaedics and Traumatology, Zmaj Jovina 30, Kragujevac, Serbia. branko.ristic@gmail.com.
authors.forename: Branko
authors.initials: B
authors.lastname: Ristić
authors.affiliation: School of Medicine, University of Belgrade, Belgrade, Serbia. drvladanstevanovic@gmail.com.|Institute for Orthopaedic Surgery "Banjica", Mihajla Avramovića 28, Belgrade, Serbia. drvladanstevanovic@gmail.com.
authors.forename: Vladan B
authors.initials: VB
authors.lastname: Stevanović
authors.affiliation: Faculty of Engineering, University of Kragujevac, Sestre Janjica 6, Kragujevac, Serbia. devedzic@kg.ac.rs.
authors.forename: Goran
authors.initials: G
authors.lastname: Devedžić
mesh_terms: D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005684:Gait / Q000502:physiology; D006801:Humans; D007259:Infrared Rays; D007593:Joint Instability / Q000175:diagnosis* / Q000209:etiology; D007718:Knee Injuries / Q000175:diagnosis* / Q000503:physiopathology; D007719:Knee Joint / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: ACL; AP translation; IE rotation; Knee; Logistic regression