title: Correction of lag screw guide pins inappropriately placed during intramedullary hip nailing.
abstract: BACKGROUND
  Lag screw position is one of the most important controllable factors in trochanteric fracture fixation. However, it is sometimes difficult to handle the lag screw guide pin during intramedullary hip nailing. In this study, causes of guide pin shift and correction of malposition were investigated.
  
  
  METHODS
  The movements of guide pins during fracture fixation were traced fluoroscopically using 35 embalmed, mainly anteverted femora, angles were measured in the anteroposterior and lateral planes and necessary corrections calculated.
  
  
  RESULTS
  In the proximal anteverted femur, posterior correction of an inappropriately placed guide pin in the lateral plane led to an inferior shift in the anteroposterior fluoroscopic view, and vice versa. Mean anteversion, alpha, beta, and beta' angles were 13.1 degrees (5-29 degrees ), 10.9 degrees (4-18 degrees ), 4.6 degrees (0-10 degrees ) and 4.4 degrees (0-9 degrees ), respectively. The beta' angle was directly proportional to the anteversion angle only, i.e. Y=0.27X+0.65 (R(2)=0.79), p<0.001.
  
  
  CONCLUSIONS
  In the proximal anteverted femur, guide pin shift in the anteroposterior fluoroscopic view occurred during correction of pin position in the lateral plane. The amount of shift was directly related to the amount of anteversion.
authors.affiliation: Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Park
authors.forename: Si Young
authors.initials: SY
authors.lastname: Park
authors.forename: Han Kook
authors.initials: HK
authors.lastname: Yoon
authors.forename: Dae Ya
authors.initials: DY
authors.lastname: Kim
authors.forename: Hye Yeon
authors.initials: HY
authors.lastname: Lee
authors.forename: Kyu Hyun
authors.initials: KH
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails; D005260:Female; D005471:Fluoroscopy; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation / Q000379:methods*; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D014963:X-Ray Intensifying Screens