Correction of lag screw guide pins inappropriately placed during intramedullary hip nailing Jin Park a , Si Young Park a , Han Kook Yoon a , Dae Ya Kim a , Hye Yeon Lee b , Kyu Hyun Yang a, * a Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea b Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea Accepted 15 April 2008 Introduction Trochanteric fracture is a leading cause of morbidity and mortality in the orthopaedic field. Among prog- nostic factors, only a few such as reduction status, type of implant and surgical technique, are con- trolled by surgeons. Reported rates of lag screw cut- Injury, Int. J. Care Injured (2008) 39, 1134—1140 www.elsevier.com/locate/injury KEYWORDS Hip fractures; Intramedullary hip nailing; Guide pin; Anteversion Summary Introduction: 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 fluor- oscopically 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, a, b, and b 0 angles were 13.18 (5—298), 10.98 (4—188), 4.68 (0—108) and 4.48 (0—98), respectively. The b 0 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. # 2008 Elsevier Ltd. All rights reserved. * Corresponding author at: Department of Orthopaedic Surgery, Yonsei University College of Medicine, Yongdong Severance Hos- pital, P.O. Box 1217, Dogok-dong, Kangnam-gu, Seoul, Republic of Korea. Tel.: +82 2 2019 3414; fax: +82 2 573 5393. E-mail address: kyang@yuhs.ac (K.H. Yang). 0020–1383/$ — see front matter # 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2008.04.014