title: The best surgical treatment for type II fractures of the dens is still controversial.
abstract: BACKGROUND
  Odontoid fractures are the most common odontoid injury and often cause atlantoaxial instability. Reports on postoperative status of patients who underwent surgery for such injuries are limited to small case series, and it is unclear whether any one technique produces better outcomes than another.
  
  
  OBJECTIVE
  We assessed the quality of the available literature for management of Type II odontoid fractures and surgery-related parameters, including surgical indications, clinical failure rate, and survivorship, postoperative ROM and function, neurologic deficits, complication and death rates, and radiographic healing rates related to either anterior dens screw or posterior C1-C2 fusion.
  
  
  METHODS
  We performed a systematic search in PubMed, Ovid, Cochrane Reviews, and Google Scholar databases. We used the methodology score proposed by Coleman et al. to rate study quality. Postoperative imaging bone union rates were extracted. Postoperative complications and neurologic impairment data were also collected.
  
  
  RESULTS
  Sixteen retrospective studies of overall low quality (average methodology score, 37.1) reporting a total of 518 patients were included. The methodology score and publication year were positively associated. The bone union rate approximated 83% (range, 33%-100%), with higher nonunion rates among patients older than 65 years. The death rate ranged widely (0%-28.6%) among different centers. Residual cervical pain was documented postoperatively from 10.5% to 26.7%, while survivorship ranged from 72% to 96.6%. No ROM data were reported.
  
  
  CONCLUSIONS
  Current data on patients who had surgery for fracture of the dens did not allow us to establish superiority of one surgical approach over another.
authors.affiliation: Department of Orthopaedics and Trauma Surgery, University Campus Bio-Medico of Rome, Via Alvaro del Portillo, 200, 00155, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Denaro
authors.forename: Rocco
authors.initials: R
authors.lastname: Papalia
authors.forename: Alberto
authors.initials: A
authors.lastname: Di Martino
authors.forename: Luca
authors.initials: L
authors.lastname: Denaro
authors.forename: Nicola
authors.initials: N
authors.lastname: Maffulli
mesh_terms: D001863:Bone Screws; D019992:Databases as Topic; D005592:Fracture Fixation / Q000295:instrumentation / Q000379:methods; D017102:Fracture Healing; D005599:Fractures, Ununited / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D009809:Odontoid Process / Q000293:injuries*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D020127:Recovery of Function; D016103:Spinal Fractures / Q000150:complications / Q000401:mortality / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods; D015996:Survival Rate; D020196:Trauma, Nervous System / Q000209:etiology