title: Analysis of using antirotational device on cephalomedullary nail for proximal femoral fractures.
abstract: OBJECTIVE
  To analyze the influence of femoral neck diameter in the positioning of the sliding screw in cefalomedulares nails for treatment of unstable transtrochanteric fractures.
  
  
  METHODS
  Prospectively throughout 2011, patients with unstable fractures transtrochanteric undergoing osteosynthesis with cephalomedullary nail using antirotacional device. They were evaluated for sex, age and fracture classification according to Tronzo. Through digital radiographs angle reduction, tip apex distance (TAD), stem diameter and measures between the positioning of the screws and the limits of the cervix were measured.
  
  
  RESULTS
  Of the 58 patients, 42 (72.4%) were female and 16 (27.6%) were male. 33 patients were classified as Tronzo III (56.9%), 6 patients as Tronzo IV (10.4%) and 19 as Tronzo V (19.8%). The majority were in between the eighth and ninth decade of life. The average reduction in the angle was 130.05° for females and 129.4° for males. The TAD average was 19.7 mm for females and 21.6 for males. The average diameter of the neck and head vary with statistical significance between men and women. In 19 patients the placement of the sliding bolt can be optimal. If the ideal positioning was not possible, the mean displacement for non-infringement of higher cortical neck was 4.06 mm.
  
  
  CONCLUSIONS
  The optimal placement would not be possible for the majority of the population, for the average diameter of the neck of the sample.
authors.affiliation: Hospital do Servidor Público Estadual de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcelo Itiro
authors.initials: MI
authors.lastname: Takano
authors.affiliation: Hospital do Servidor Público Estadual de São Paulo, São Paulo, SP, Brazil.
authors.forename: Ramon Candeloro Pedroso
authors.initials: RC
authors.lastname: de Moraes
authors.affiliation: Hospital do Servidor Público Estadual de São Paulo, São Paulo, SP, Brazil.
authors.forename: Luis Gustavo Morato Pinto
authors.initials: LG
authors.lastname: de Almeida
authors.affiliation: Hospital do Servidor Público Estadual de São Paulo, São Paulo, SP, Brazil.
authors.forename: Roberto Dantas
authors.initials: RD
authors.lastname: Queiroz
keywords: Bone nails; Fracture fixation, internal; Hip fractures