title: Exchange nailing for aseptic nonunion of femoral shaft: a retrospective cohort study for effect of reaming size.
abstract: BACKGROUND
  Exchange nailing has been the favored method to treat aseptic nonunions of the femoral shaft. The recommended amount of over-reaming is at least 2 mm. The purpose of this study was to determine whether the effectiveness of nonunion treatment is greatly reduced with less than 2 mm of over-reaming.
  
  
  METHODS
  Aseptic nonunions of the femoral shaft were treated by exchange nailing with 1 mm (n = 37) or at least 2 mm (n = 44) of over-reaming. Union rates, union periods, and complications were compared. Indications for exchange nailing were aseptic nonunions of the femoral shaft with an inserted intramedullary nail, shortening of less than 1.5 cm, and a fracture gap of less than 5 mm.
  
  
  RESULTS
  After a mean follow-up of 3.6 years (range, 1.1-7.1 years), union rates were 31 (91.2%) of 34 nonunions with over-reaming of 1 mm and 37 (92.5%) of 40 nonunions with over-reaming of 2 mm or more (p = 0.32). The mean union periods were 4.4 months (range, 2.5-8 months) and 4.4 months (range, 3-8 months), respectively (p = 0.83). Except for persistent nonunions, no significant complications occurred.
  
  
  CONCLUSIONS
  Exchange nailing can be considered the first choice to treat aseptic nonunions of the femoral shaft. The diameter of the new intramedullary nail should be as large as possible to reinforce the mechanical strength of the repair. The osteogenic potential stimulated by the reaming of cancellous bone graft was similar with over-reaming of 1 mm and with over-reaming of 2 mm or more.
authors: Chang Gung Memorial Hospital, Taiwan. ccwu@mail.cgu.edu.tw
authors: Chi-Chuan
authors: CC
authors: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001858:Bone Nails; D015331:Cohort Studies; D005260:Female; D005264:Femoral Fractures / Q000503:physiopathology / Q000601:surgery*; D005500:Follow-Up Studies; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation / Q000379:methods*; D017102:Fracture Healing; D005599:Fractures, Ununited / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D016896:Treatment Outcome