title: [Effect of blocking screws on breakage of interlocking intramedullary nails].
abstract: OBJECTIVE
  To explore the effect of blocking screws on the breakage of interlocking intramedullary nails.
  
  
  METHODS
  From January 2003 to August 2005, 56 patients with fresh and close fracture of long shafts were treated by interlocking intramedullary nails. Among them, there were 32 males and 24 females, including 26 femoral fracture and 30 tibial fracture. Fracture of femoral and tibial shaft was fixed with interlocking intramedullary nails normally in group I (n=32). And long oblique, spiral, proximal or distal fracture of bone shaft was fixed with interlocking intramedullary nails and blocking screws in group II (n=24).
  
  
  RESULTS
  All cases were followed up 12 to 21 months (16 months on average). In group I, fracture healing failed and the intramedullary nails broke in 3 cases, breakage site was the middle femoral fracture area in 1 case and the first distal interlocking nail hole in 2 cases of distal 1/3 tibial fracture. Fractures healed 6 to 12 months after operations in the other cases, but more bony callus occurred in fracture area. In group II, fractures healing and good alignment were achieved, and no breakage was found in all 24 cases.
  
  
  CONCLUSIONS
  The use of blocking screws added to interlocking intramedullary nails could improve the stability of fracture areas distinctively, and hence reduce the breakage of intramedullary nails.
authors.affiliation: Department of Orthopaedics II, the 2nd Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou Ilenan, 450002, PR China. ajw73@sohu.com
authors.forename: Jinwei
authors.initials: J
authors.lastname: Ai
authors.forename: Pei
authors.initials: P
authors.lastname: Li
authors.forename: Yeping
authors.initials: Y
authors.lastname: Han
mesh_terms: D001863:Bone Screws; D005260:Female; D005264:Femoral Fractures / Q000601:surgery*; D005500:Follow-Up Studies; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation* / Q000379:methods; D017102:Fracture Healing; D005596:Fractures, Closed / Q000601:surgery*; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000517:prevention & control; D013978:Tibial Fractures / Q000601:surgery*; D016896:Treatment Outcome