title: Interobserver and intraobserver agreement of ligamentous injuries on conventional MRI after simple elbow dislocation.
abstract: The primary objective of this study was to assess the interobserver and intraobserver agreement on ligamentous injuries on conventional magnetic resonance imaging (MRI) in acute simple elbow dislocation. The secondary objectives were to determine the interobserver agreement on the assessment of joint congruity, joint effusion, loose bodies and chondral lesions on conventional MRI.
  
  
  
  Conventional MRIs (1.5 Tesla, elbow specific surface coil) of 30 patients (40.7 years; range 14-72) with simple elbow dislocations were evaluated by four blinded examiners. An analysis of the interobserver agreement of all raters and for several subgroups (radiologists, orthopaedics, experienced, non-experienced) was performed. The examiners assessed the integrity (intact, partial tear, complete tear) of the lateral collateral ligament (LCL), medial collateral ligament (MCL), extensor and flexor tendons, as well as the presence of joint congruity, joint effusion, loose bodies and chondral lesions. Agreement strength, correlation and proportion of exact agreement were determined for interobserver agreement, and intraobserver agreement analyses.
  
  
  
  Interobserver agreement of all examiners was fair to moderate for collateral ligaments (LCL: 0.441, MCL: 0.275). Exact agreement of all raters was found in 33.3% for the LCL and in 26.7% for the MCL. The both experienced examiners showed highest agreement strength for the LCL (0.619) and the radiologists showed highest agreement strength for the MCL (0.627), the proportion of exact agreement was 60.0% in both categories. A high proportion of exact agreement regarding joint congruity (90%), joint effusion (100%), loose bodies (96.7%) and chondral lesion (80%) was found among the radiologists. The evaluation of the intraobserver agreement revealed slight to substantial agreement (0.227 to 0.718) for the collateral ligaments.
  
  
  
  This study shows difficulties in the evaluation of ligaments by conventional MRI technique as demonstrated by a weak inter- and intraobserver agreement. This should be the basis to develop new MRI quality standards with special focus on coronal oblique reconstructions to improve the evaluation of ligament injuries after simple elbow dislocations.
authors.affiliation: Clinic for Trauma and Orthopaedic Surgery, BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwig-Guttmann-Strasse 13, Ludwigshafen on the Rhine, 67071, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Schnetzke
authors.affiliation: Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Schüler
authors.affiliation: Department for Radiology, Klinikum der Stadt Ludwigshafen gGmbH, Ludwigshafen on the Rhine, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Hoffend
authors.affiliation: Clinic for Trauma and Orthopaedic Surgery, BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwig-Guttmann-Strasse 13, Ludwigshafen on the Rhine, 67071, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Simon
authors.affiliation: Clinic for Trauma and Orthopaedic Surgery, BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwig-Guttmann-Strasse 13, Ludwigshafen on the Rhine, 67071, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Keil
authors.affiliation: Clinic for Trauma and Orthopaedic Surgery, BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwig-Guttmann-Strasse 13, Ludwigshafen on the Rhine, 67071, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Porschke
authors.affiliation: Clinic for Trauma and Orthopaedic Surgery, BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwig-Guttmann-Strasse 13, Ludwigshafen on the Rhine, 67071, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Studier-Fischer
authors.affiliation: Clinic for Trauma and Orthopaedic Surgery, BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwig-Guttmann-Strasse 13, Ludwigshafen on the Rhine, 67071, Germany.
authors.forename: Paul-Alfred
authors.initials: PA
authors.lastname: Grützner
authors.affiliation: Clinic for Trauma and Orthopaedic Surgery, BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwig-Guttmann-Strasse 13, Ludwigshafen on the Rhine, 67071, Germany. guehring@uni-heidelberg.de.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Guehring
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017885:Collateral Ligaments / Q000000981:diagnostic imaging* / Q000293:injuries*; D004551:Elbow Joint / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000592:standards*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D016059:Range of Motion, Articular; D016037:Single-Blind Method; D055815:Young Adult; D000092464:Elbow Injuries
keywords: Coronal oblique view; Elbow dislocation; Interobserver; Intraobserver; Lateral collateral ligaments; Lateral ulnar collateral ligament; MRI; Medial collateral ligaments; Simple elbow dislocation