title: Magnetic resonance imaging-based classification for ulnar collateral ligament injuries of the elbow.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) arthrography has been considered the gold standard for imaging ulnar collateral ligament (UCL) injuries. No classification system has been described for UCL tears to help discuss and guide treatment options. We propose that an MRI-based UCL classification system would correlate with valgus laxity and help predict surgical management.
  
  
  METHODS
  The MRIs from 240 patients who underwent UCL reconstruction were reviewed and classified according to a system based on severity and location of the UCL injury. Bilateral elbow valgus stress radiographs were used to compare the amount of valgus laxity associated with each grade of UCL injury. Additional data from the imaging review included intraligamentous calcifications, T-sign presence, and a newly described "vacuum sign."
  
  
  RESULTS
  The amount of valgus stress opening increased with the classification severity as follows: type I, 0.13 mm; type II, 0.20 mm; type III, 0.63 mm; and type IV, 0.76 mm.
  
  
  CONCLUSIONS
  We propose a new classification for UCL injuries based on MRI findings that helps predict valgus laxity, improve communication, and guide treatment for UCL pathology in throwing athletes.
authors: Bone & Joint/Sports Medicine Institute, Naval Medical Center Portsmouth, Portsmouth, VA, USA. Electronic address: patrick.w.joyner4.mil@mail.mil.
authors: Patrick W
authors: PW
authors: Joyner
authors: Erlanger Health System, University of Tennessee College of Medicine, Chattanooga, TN, USA.
authors: Jeremy
authors: J
authors: Bruce
authors: University Specialty Clinics, University of South Carolina School of Medicine, Columbia, SC, USA.
authors: Ryan
authors: R
authors: Hess
authors: College of Medicine, The University of South Alabama, Mobile, AL, USA.
authors: Arron
authors: A
authors: Mates
authors: The University of South Carolina School of Medicine, Columbia, SC, USA.
authors: Frederic Baker
authors: FB
authors: Mills
authors: The Andrews Institute for Orthopaedics & Sports Medicine, Gulf Breeze, FL, USA.
authors: James R
authors: JR
authors: Andrews
mesh_terms: D000328:Adult; D001134:Arm Injuries / Q000000981:diagnostic imaging / Q000601:surgery*; D000070637:Collateral Ligament, Ulnar / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D004551:Elbow Joint / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008279:Magnetic Resonance Imaging; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D000092464:Elbow Injuries
keywords: Ulnar collateral ligament; elbow MRI; elbow radiograph; high-grade partial tear; low-grade partial tear; vacuum sign; valgus stress