title: Intramedullary bone formation after intramedullary nailing.
abstract: OBJECTIVE
  To determine the gross structural alterations of the nailed bone (femur or tibia) after the removal of an intramedullary nail (IMN).
  
  
  METHODS
  Prospective, consecutive, patient series.
  
  
  METHODS
  Academic, level 1 trauma center.
  
  
  METHODS
  Eighteen patients (14 patients with a femoral and 4 patients with a tibia nail) underwent an IMN removal from their femur or tibia.
  
  
  METHODS
  Every patient had a spiral computed tomography scan and a plain X-ray study, immediately after the nail removal and also at their latest follow-up (24-30 months). The 4 patients with a tibia nail were additionally examined using a peripheral quantitative computed tomography study at their latest follow-up.
  
  
  METHODS
  Structural alterations of the nailed bone (femur or tibia) after the removal of the IMN in asymptomatic patients.
  
  
  RESULTS
  An intramedullary shell of compact bone was demonstrated around the nail track. This new bone was apparent on plain radiographs in all of the patients. Peripheral quantitative computed tomography study revealed that the density of the bony ring was similar to that of subcortical bone. The histologic examination of the intramedullary shell of one of our patients suggested that the bony ring was made of cortical bone.
  
  
  CONCLUSIONS
  Intramedullary nailing may enhance new cortical bone formation within the bone marrow cavity. This 'cortical bone' still exists more than 2 years after implant removal. Nail insertion also causes thickening of the normal cortex at the sites of nail-cortex contact where loads are transferred from the nail to the cortex.
authors.affiliation: Department of Orthopaedics, Thriasio General Hospital, Elefsina, Greece. snapmd@gmail.com
authors.forename: Stamatios A
authors.initials: SA
authors.lastname: Papadakis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Segkos
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Katsiva
authors.forename: Pantoula
authors.initials: P
authors.lastname: Panagiota
authors.forename: Alexia
authors.initials: A
authors.lastname: Balanika
authors.forename: Vasilios
authors.initials: V
authors.lastname: Stavrianos
authors.forename: Ioanna
authors.initials: I
authors.lastname: Mpalia
authors.forename: Pavlos
authors.initials: P
authors.lastname: Katonis