title: Anterior interbody fusion of the cervical spine with Zero-P spacer: prospective comparative study-clinical and radiological results at a minimum 2 years after surgery.
abstract: METHODS
  A prospective study.
  
  
  OBJECTIVE
  The aim of this study was to compare clinical and radiological efficacy of anterior cervical microdiscectomy and fusion done by the newly designed low-profile interbody spacer in cases of symptomatic cervical spine spondylosis.
  
  
  BACKGROUND
  There are basically 2 ways to provide interbody fusion in the degenerative cervical spine; the first is by way of an unanchored "stand-alone" bone graft or cage, and the second is with bone graft or a cage anchored with a plate. Both concepts have their own benefits as well as potential drawbacks. Low-profile angle-stable spacer Zero-P is an implant that can potentially limit the drawbacks of both these procedures. METHODS.: Prospective study collecting clinical and radiological data of 77 patients undergoing anterior cervical interbody fusion of 1 or 2 motion segments from C3-C7 was performed. Zero-P spacer was used in 44 patients (55 segments) and in 33 cases (41 segments), stabilization was done using interbody spacer and dynamic anterior cervical plate. Patients were followed a minimum of 2 years after surgery.
  
  
  RESULTS
  There was no significant difference in neck disability index values, presence of dysphagia (P = 0.308), and Cobb C values during follow-up (P = 0.051) between both groups. A significant difference in the first 2 values of Cobb S was found (P < 0.001), but the next course of Cobb S changes showed no difference in either group. No difference was found in the radiological stability during follow-up, and no revision surgery was done.
  
  
  CONCLUSIONS
  The results of this study confirm biomechanical assumptions associated with the Zero-P spacer. Implantation of this new cage results in setting required biomechanical conditions in the treated segment that are comparable with those when the segment is treated with a dynamic plate. However, the potential of the mentioned implant to reduce the incidence of postoperative dysphagia was not proven on this sample of patients.
authors.affiliation: Department of Neurosurgery, Charles University, 1st Faculty of Medicine, Military University Hospital, Prague, Czech Republic. petr.vane@uvn.cz
authors.forename: Petr
authors.initials: P
authors.lastname: Vanek
authors.forename: Ondrej
authors.initials: O
authors.lastname: Bradac
authors.forename: Patricia
authors.initials: P
authors.lastname: Delacy
authors.forename: Jiri
authors.initials: J
authors.lastname: Lacman
authors.forename: Vladimir
authors.initials: V
authors.lastname: Benes
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D016025:Bone Transplantation / Q000295:instrumentation / Q000379:methods; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019736:Prostheses and Implants; D011859:Radiography; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013997:Time Factors; D016896:Treatment Outcome