title: Does Vertebral Endplate Morphology Influence Outcomes in Lumbar Total Disc Arthroplasty? Part II: Clinical and Radiographic Results as Evaluated Utilizing the Vertebral Endplate Yue-Bertagnoli (VEYBR) Classification.
abstract: METHODS
  This study was a prospective study with a minimum patient follow-up of 2 years. Objective The purpose of this study was to evaluate the clinical usefulness of a vertebral endplate classification system (VEYBR) in predicting outcomes following lumbar arthroplasty.
  
  
  BACKGROUND
  In the present study, our previously described endplate classification system was evaluated to determine its clinical usefulness in patients undergoing lumbar arthroplasty.
  
  
  METHODS
  The patient cohort in this study consisted of 80 patients who had been enrolled in the US FDA ProDisc clinical trial. Radiographs were classified using the VEYBR classification. The preoperative categories (Types I to V) were then correlated with the patients' visual analogue scores (VAS) and Oswestry Disability Index (ODI) scores and radiographic outcomes at an average follow-up point of 28 months.
  
  
  RESULTS
  The rank order of total change in VAS based on preoperative VEYBR classification was Type IV, III, I II, and V, with Type IV having the greatest improvement in VAS and Type V having the least improvement. The rank order of total change in ODI was Type IV, II, III, I, and V. We found no differences in clinical outcomes among the 5 vertebral endplate types. Type II endplates had least optimal sagittal positioning.
  
  
  CONCLUSIONS
  Although not statistically significant, there was a strong trend for Type V endplates to have the least improvements in VAS and Oswestry clinical outcome scores. Knowledge and use of the endplate classification system did lead to consistent implant placement across endplate classes which may indicate the usefulness of this classification system in preoperative planning, especially for physicians in the "learning curve" phase of this procedure.
  
  
  METHODS
  Case series (Level IV).
authors: Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut.
authors: Matthew E
authors: ME
authors: Oetgen
authors: Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut.
authors: James J
authors: JJ
authors: Yue
authors: Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut.
authors: Jorge J Jaramillo-de
authors: JJ
authors: la Torre
authors: St. Elizabeth's Klinikum, Straubing, Germany.
authors: Rudolf
authors: R
authors: Bertagnoli
keywords: Lumbar; clinical and radiographic outcomes; endplate morphology; total disc replacement