title: A unique device, the disc space-fitted distraction device, for anterior cervical discectomy and fusion: early clinical and radiological evaluation.
abstract: OBJECTIVE
  To perform interbody distraction and to obtain spinal curvature correction during anterior cervical discectomy and fusion (ACDF), the authors recently adopted a new stand-alone device, a disc space-fitted distraction device (DFDD). In this preliminary report the authors introduce this unique device and discuss some advantages in terms of short-term clinical and radiological evaluations.
  
  
  METHODS
  The most unique aspect of the DFDD is the function of gentle distraction at anterior disc space with maximum lordotic correction of up to 8 degrees while rotating a screw at the front of the device. Additional advantages are related to its configuration such as disc space-matched shape in all dimensions, tapering contour for easy insertion into the disc space, multiple spikes to avoid dislodgment, wider contact area to the vertebral endplate for diminishing sinking process, and sufficient space for accommodation of bone-conductive materials. Twenty-four patients who have been observed more than 12 months after ACDF were involved in this evaluation.
  
  
  RESULTS
  The objective clinical outcome, measured by the Neurological Cervical Spine Scale, was significantly improved. In radiological evaluation, statistically significant improvement compared with preoperative values was noted on the curvature index, C2-7 curvature, and disc angle (p < 0.01) throughout the entire postoperative period, up to 12 months. A high fusion rate and remodeling process around the implants were also observed.
  
  
  CONCLUSIONS
  The DFDD may have some advantages over other devices-its distraction action, diminished sinking, and early solid bone union resulted in maintaining sufficient correction of the spinal curvature. This corrected spinal curvature may play an important role in preventing progressive adjacent-disc degeneration subsequent to ACDF in the long term.
authors.affiliation: Department of Neurosurgery, Jikei University School of Medicine, Tokyo, Japan. tani@jikei.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tani
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Nagashima
authors.forename: Akira
authors.initials: A
authors.lastname: Isoshima
authors.forename: Masahiko
authors.initials: M
authors.lastname: Akiyama
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ohashi
authors.forename: Satoru
authors.initials: S
authors.lastname: Tochigi
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Abe
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D017586:Diskectomy / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008141:Lordosis / Q000601:surgery*; D009984:Orthopedic Fixation Devices; D011184:Postoperative Period; D011859:Radiography; D013123:Spinal Fusion / Q000295:instrumentation*; D013997:Time Factors; D016896:Treatment Outcome