title: A Comparison of fixed-hole and slotted-hole dynamic plates for anterior cervical discectomy and fusion.
abstract: METHODS
  A retrospective review of clinical data at 1 institution was performed.
  
  
  OBJECTIVE
  To compare the clinical and radiologic outcomes between fixed-hole and slotted-hole dynamic cervical plates.
  
  
  BACKGROUND
  Anterior cervical plating is commonly used to increase stability and promote spinal fusion. Two techniques, fixed-hole dynamic plating that uses variable angled screws and slotted-hole dynamic plating that permits sliding, are viable options, but there have been no clinical studies comparing their effectiveness.
  
  
  METHODS
  Fifty-six patients at 1 institution having anterior cervical discectomy and fusion for degenerative disease over a 5-year period were entered into this study. Surgeries were performed with 1 of the dynamic plates for 1 to 3 levels. For the slotted-hole dynamic plate group, a slotted-hole plate was used (ABC, Aesculap, Tuttlingen, Germany or C-tek, Biomet, Parssipany, NJ) and for the fixed-hole dynamic plated group, a variable angled screw was used (C-tek, Biomet, Parssipany, NJ). Radiographic measurements included were graft subsidence, lordotic angle change from each end plate of fusion construct, and implant translation from end plates after a minimum of 12 months follow-up. Fusion state and clinical outcome using Odom's criteria were also evaluated.
  
  
  RESULTS
  Demographics were not different among patient populations. The average age of the patients was 51.0 years (range: 27 to 77 y). Mean follow-up period was 20.6 months (range: 12 to 41 mo). Slotted-hole dynamic plates were used for 29 patients (ABC plate, 17; C-tek plate, 12) and fixed-hole dynamic plates for 27 patients. Clinical outcomes and pseudoarthrosis rates were similar for both types of plates. Radiographic measurements showed a statistically significant increased incidence of graft subsidence and implant translation with the slotted-hole dynamic plates. Loss of lordosis was also greater in the slotted-hole dynamic plated group, although the difference was not statistically significant.
  
  
  CONCLUSIONS
  The use of a fixed-hole dynamic plate is more favorable in regards to graft subsidence and implant translation in the follow-up period, although clinical outcome and fusion rates are similar in patients with either the fixed-hole or slotted-hole dynamic plates.
authors.affiliation: Department of Orthopaedic Surgery, Wooridul Spine Hospital, Seoul, Korea.
authors.forename: Soon-Woo
authors.initials: SW
authors.lastname: Hong
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Larry T
authors.initials: LT
authors.lastname: Khoo
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Yoon
authors.forename: Langston T
authors.initials: LT
authors.lastname: Holly
authors.forename: Arya Nick
authors.initials: AN
authors.lastname: Shamie
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D001860:Bone Plates / Q000009:adverse effects / Q000592:standards* / Q000706:statistics & numerical data; D016025:Bone Transplantation / Q000379:methods; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D017586:Diskectomy / Q000295:instrumentation* / Q000379:methods; D004868:Equipment Failure / Q000706:statistics & numerical data; D005260:Female; D005548:Foreign-Body Migration / Q000453:epidemiology / Q000517:prevention & control; D006085:Graft Survival / Q000502:physiology; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods; D011542:Pseudarthrosis / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D055009:Spondylosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013314:Stress, Mechanical; D016474:Weight-Bearing / Q000502:physiology; D021801:Zygapophyseal Joint / Q000473:pathology / Q000601:surgery