title: Biomechanical comparision of femoral intramedullary nails for interfragmentary rotational stability.
abstract: OBJECTIVE
  This study aims to investigate which intramedullary nail is biomechanically better for establishing interfragmentary rotational stability.
  
  
  METHODS
  Thirty composite femurs were utilized in this study. We analyzed interfragmentary rotational arc displacements between 10 Nm external-6 Nm internal torques and 6 Nm external-6 Nm internal torques which imitate rotation torques while walking on a flat surface and descending stairs by administering 10 interlocking nails, 10 compression nails, and 10 Mehmet anti-rotation nails with tube compression.
  
  
  RESULTS
  Maximum interfragmentary rotation arc displacement between 10 Nm external rotation and 6 Nm internal rotation torques was mean 1.64 mm in the Mehmet nail compressed by 7 Nm torque wrench. This value was lower by 309% (6.72 mm) from interlocking nail (p=0.000), 201% (5.42 mm) from compression nail compressed by 2.5 Nm torque wrench (p=0.000), and 26% (1.92 mm) from compression nail compressed by 7 Nm torque wrench (p>0.05).
  
  
  CONCLUSIONS
  In axially stable transvers and short oblique femur fractures, Mehmet nail is superior to other intramedullary nails with limited movement between locking screw and hole, more interfragmentary compression without locking screw deformation, and no proximal nail migration.
authors.affiliation: Department of Orthopedics and Traumatology, Medical Faculty of Şifa University, 35100 Bornova, İzmir, Turkey. aakaraarslan@yahoo.com.
authors.forename: Ahmet Adnan
authors.initials: AA
authors.lastname: Karaarslan
authors.forename: Hakan
authors.initials: H
authors.lastname: Aycan
authors.forename: Aslan
authors.initials: A
authors.lastname: Mayda
authors.forename: Fatih
authors.initials: F
authors.lastname: Ertem
authors.forename: Erhan
authors.initials: E
authors.lastname: Sesli
mesh_terms: D001696:Biomechanical Phenomena; D001858:Bone Nails / Q000009:adverse effects / Q000145:classification / Q000592:standards; D001863:Bone Screws; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D006801:Humans; D011183:Postoperative Complications / Q000517:prevention & control*; D012399:Rotation; D019415:Torque; D014102:Torsion Abnormality / Q000209:etiology / Q000517:prevention & control