Original Article The Effect of Prophylactic Cerclage Wires in Primary Total Hip Arthroplasty: A Biomechanical Study Andrew C. Waligora IV, MD, John R. Owen, MS, Jennifer S. Wayne, PhD * , Shane R. Hess, DO, Gregory J. Golladay, MD, William A. Jiranek, MD Department of Orthopaedic Surgery and Biomedical Engineering, Orthopaedic Research Laboratory, Virginia Commonwealth University, Richmond, Virginia article info Article history: Received 7 June 2016 Received in revised form 18 November 2016 Accepted 15 January 2017 Available online xxx Keywords: periprosthetic cerclage fracture arthroplasty hip cementless abstract Background: Despite literature to support the use of various cerclage techniques to address intra- operative femoral fractures in total hip arthroplasty, there are limited data to support prophylactic cerclage wiring of the femur during cementless implant placement. This study aims to evaluate the effect of prophylactic calcar cerclage wires on the biomechanical parameters required to produce periprosthetic femoral fractures and on the morphology of these fracture patterns in stable cementless femoral implants. Methods: Ten pairs of matched fresh frozen cadaveric femurs were implanted with anatomic tapered cementless implants with or without the addition of 2 monofilament calcar wires. Specimens were axially loaded and externally rotated to failure. Initial torsional stiffness, rotation and energy to failure, and torque at failure were measured. Statistical significance was set at P < .05. Fracture patterns were classified according to a well-known classification system. Results: Wired specimens required significantly more rotation (P ¼ .039) and energy to failure (P ¼ .048). No significant difference was detected in initial torsional stiffness (P ¼ .63) or torque at failure (P ¼ .10). All unwired samples developed a Vancouver B2 fracture pattern. Seven of the 8 wired specimens also developed a Vancouver B2 fracture pattern, while the eighth wired specimen developed a Vancouver B1 fracture pattern. Conclusion: Prophylactic cerclage wire placement increases the rotation and energy to failure in well- fixed press-fit femoral implants. The increase in torsional energy needed for failure may reduce the risk of early periprosthetic fracture. Further studies are needed to evaluate cost vs benefit and long-term outcomes of prophylactic wiring. Based on the results of our study, consideration of prophylactic wiring should be addressed on a case-to-case basis. © 2017 Elsevier Inc. All rights reserved. Obtaining initial mechanical stability of cementless femoral implants during total hip arthroplasty (THA) is necessary to reduce micromotion so that bony fixation can reliably occur [1,2]. A well- known complication during the placement of cementless femoral implants is intraoperative fracture. The incidence of intraoperative fractures has been noted to be between 1.5% and 27.8% [2-5]. These fractures most commonly occur during femoral preparation [6] as the surgeon attempts to attain optimal initial stability [2,4,5,7-9]. Unidentified insertional fractures may propagate [10] and may compromise initial mechanical stability, which adversely affects bony ingrowth, resulting in early loosening [6,10]. Implant survi- vorship has not been shown to be affected when these fractures are identified and appropriately addressed [3,4,6,11]. Intraoperative femoral fractures tend to occur around the calcar and current treatment algorithms employ the use of cerclage techniques [6,7,10,12,13]. Cerclage wiring reduces fracture propagation by increasing the resistance to hoop stresses [5]. A single cerclage wire can provide stem stability at 890 N of load in the presence of a fracture [10]. However, the effect of cerclage wires in improving the resistance to fracture occurrence or propagation from torsional load has not been previously investigated. Prophylactic use of 2-mm cerclage cables around the calcar has been proposed from a biomechanical analysis demonstrating an increase in hoop stress resistance [5]. Additionally, there have been One or more of the authors of this paper have disclosed potential or pertinent conflicts of interest, which may include receipt of payment, either direct or indirect, institutional support, or association with an entity in the biomedical field which may be perceived to have potential conflict of interest with this work. For full disclosure statements refer to http://dx.doi.org/10.1016/j.arth.2017.01.019. * Reprint requests: Jennifer S. Wayne, PhD, Department of Orthopaedic Surgery and Biomedical Engineering, Orthopaedic Research Laboratory, Virginia Common- wealth University, P.O. Box 843067, Richmond, VA 23284-3067. Contents lists available at ScienceDirect The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org http://dx.doi.org/10.1016/j.arth.2017.01.019 0883-5403/© 2017 Elsevier Inc. All rights reserved. The Journal of Arthroplasty xxx (2017) 1e5