Correction of lag screw guide pins inappropriately placed during intramedullary hip nailing.
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.
Park
Jin
J
Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
Park
Si Young
SY
Yoon
Han Kook
HK
Kim
Dae Ya
DY
Lee
Hye Yeon
HY
Yang
Kyu Hyun
KH
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