title: Role of plate thickness as a cause of dysphagia after anterior cervical fusion.
abstract: METHODS
  Prospective radiographic analysis with clinical correlates.
  
  
  OBJECTIVE
  The purpose of this study was to determine whether patients with cervical plates protruding off the vertebral body more prominently than pre-existing osteophytes had higher rates of dysphagia, suggesting a mechanical role.
  
  
  BACKGROUND
  Plate prominence due to mechanical causes has been implicated as a cause of dysphagia after anterior cervical fusion. This study therefore assessed the potential of plate prominence as a cause of dysphagia after anterior cervical fusion and the predictive role of preoperative osteophyte heights.
  
  
  METHODS
  Osteophyte heights measured on the preoperative radiographs of 63 patients, 41 males and 23 females with mean age 54 years (range, 31 to 75), who underwent anterior fusion (2 mm SYNTHES CSLP plates). After surgery, the distance of the plate from the vertebral body was measured and compared with preoperative osteophyte heights. Group I contained 30 patients who had cervical plates protrude less than or equal to the height of the tallest preoperative osteophyte. Group II contained 34 patients who had plates protrude greater than the height of the tallest preoperative osteophyte.
  
  
  RESULTS
  No patients had preoperative dysphagia. Five of 30 Group I patients had dysphagia (>1 month). Six of 34 group II patients had dysphagia. There was no difference between groups I and II in rate of dysphagia (beta > 0.90). Plates at C3 and shorter cervical constructs trended higher rates of dysphagia.
  
  
  CONCLUSIONS
  Long-term postoperative dysphagia in Group I patients and the lack of a difference in rates of dysphagia between group I and group II, made it improbable plate thickness of 2 mm or prominence between 3 and 7 mm consistently played roles in dysphagia. Preoperative osteophyte height did not predict which patients developed postoperative dysphagia. Plates at the C3 and shorter constructs trended to have higher rates of dysphagia.
authors.affiliation: Division of Spine Surgery, Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania and the University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. kingsleychin@hotmail.com
authors.forename: Kingsley R
authors.initials: KR
authors.lastname: Chin
authors.forename: James R
authors.initials: JR
authors.lastname: Eiszner
authors.forename: Samuel B
authors.initials: SB
authors.lastname: Adams
mesh_terms: D000328:Adult; D000368:Aged; D001860:Bone Plates / Q000009:adverse effects*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D019299:Decompression, Surgical; D003680:Deglutition Disorders / Q000453:epidemiology / Q000209:etiology*; D004867:Equipment Design; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D011859:Radiography; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013128:Spinal Osteophytosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*