Factors influencing neck anteversion during femoral nailing: A retrospective analysis of 220 torsion-difference CTs § Emmanouil Liodakis a, *, Mohamed Kenawey b , Max Petri a , Azad Zu ¨ mru ¨t a , Nael Hawi a , Christian Krettek a , Musa Citak a a Trauma Department, Hannover Medical School, Carl Neuberg Str. 1, 30625 Hannover, Germany b Orthopaedic Surgery Department, Sohag University Hospital, 82524 Sohag, Egypt Femoral-shaft fractures are the most common long-bone fractures, and locked intramedullary nailing is the treatment of choice for these fractures. 1–3 The main advantages of closed intramedullary nailing are that small fragments are not separated from the surrounding soft tissue and that the fracture haematoma is not drained. 4 Rotational malalignment is a well-known complica- tion following intramedullary nailing because both fracture reduc- tion and nailing are performed as semi-closed procedures, making it impossible to secure an anatomical reduction under direct vision. 5 Despite the enormous advances in navigation technology and the new generation of intramedullary nails, the problem of torsional deformities is not adequately solved. Femoral anteversion in normal populations varies tremendous- ly. However, the difference in anteversion between both sides of the same individual is small. Strecker et al. 6 reported that the median of these differences in adults with healthy paired femora was 48 and that only 5% of them had anteversion differences 118 or more and 1% had differences of 138 or more. Conversely, clinical studies in patients with femoral fractures report an incidence of 43% for anteversion differences of 108 or more and 28% for malrotations of 158 or more. 3,5,7 A recent study of Bretin et al. 8 showed that torsional deformities of more than 158 (true torsional deformities) are not only a cosmetic problem but may cause true complaints and are changing the knee-joint biomechanics. Jaarsma et al. 7 also showed that patients with true torsional deformities subsequent to closed femoral nailing had difficulties with demanding activities, such as running, sports and climbing stairs. The goal of this retrospective study is to objectively evaluate factors (e.g., position of the patient on the operating table, nailing technique and time interval till operation) that possibly interfere with the incidence of torsional deformities after femoral fractures. Injury, Int. J. Care Injured 42 (2011) 1342–1345 A R T I C L E I N F O Article history: Accepted 3 June 2011 Keywords: Femoral neck anteversion Torsion-difference CT Learning curve Surgical position Intramedullary nailing A B S T R A C T Background: Rotational malalignment is a well-known complication following intramedullary nailing of femoral shaft fractures. The hypothesis of this study is that various modifiable factors, such as position on the surgical table or nailing technique, influence the incidence of torsional abnormalities. Methods: For this retrospective study, we analysed the data of 220 consecutive patients with femoral shaft fractures and postoperative torsion-difference computed tomographies (CTs), performed from 2001 to 2009 in our institution. Mean age of the patients was 33  15 years. Average delay to surgery was 8  11 days. The average postoperative neck anteversion difference between both sides was 11  88. A p value <0.05 was considered to be statistically significant. Results: The average postoperative neck anteversion difference between both sides was not significantly affected from the position of the patient on the surgical table (supine or lateral, p = 0.698), the delay till surgery (p = 0.989), the nailing technique (antegrade or retrograde, p = 0.793; reamed or unreamed, p = 0.930), the type of the implant (p = 0.885) and the experience of the surgeon (p = 0.055). Furthermore, the learning curve regarding this complication was long and not predictable. Conclusions: We could not identify any risk factors that are associated with an increased incidence of torsional deformities, and thus our hypothesis could not be confirmed. The inability to identify such risk factors renders the prevention of this complication particularly problematic. The invention of new techniques for better intra-operative control of the torsion is probably the only solution to further reduce the incidence of postoperative malrotational deformities. ß 2011 Elsevier Ltd. All rights reserved. § This work was performed at the Medical School Hannover, Hannover, Germany. The study was performed according to the international guidelines of the Declaration of Helsinski. * Corresponding author. Tel.: +49 511 532 2026; fax: +49 511 532 5877. E-mail address: manoliodakis@yahoo.gr (E. Liodakis). Contents lists available at ScienceDirect Injury jo ur n al ho m epag e: ww w.els evier .c om /lo cat e/inju r y 0020–1383/$ – see front matter ß 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2011.06.004