Original Research Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures Ahmet Karakasli, MD 1 , Onur Hapa, MD 2 , Mehmet Erduran, MD 2 , Cemal Dincer, MD 3 , Berivan Cecen, PhD 4 , Hasan Havitcioglu, MD 5 1 Assistant Professor, Department of Orthopaedics and Traumatology, Dokuz Eylul University Faculty of Medicine, Izmir, Turkey 2 Associate Professor, Department of Orthopaedics and Traumatology, Dokuz Eylul University Faculty of Medicine, Izmir, Turkey 3 Orthopedist Research Assistant, Department of Orthopaedics and Traumatology, Dokuz Eylul University Faculty of Medicine, Izmir, Turkey 4 Biomechanics Research Assistant, Department of Biomechanics, Institute of Health Sciences, Dokuz Eylul University, Izmir, Turkey 5 Professor, Department of Orthopaedics and Traumatology, Dokuz Eylul University Faculty of Medicine, Izmir, Turkey article info Level of Clinical Evidence: 5 Keywords: headless screw locking plate talar neck fractures abstract For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A repro- ducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p ¼ .655), yield load (p ¼ .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues. Ó 2015 by the American College of Foot and Ankle Surgeons. All rights reserved. Fractures of the neck of the talus are relatively rare, accounting for roughly 1% of all fractures and 3% of all foot fractures; however, they account for 50% of all talar fractures (1). The talus has a unique anatomic shape and function. Without direct muscle at- tachments, it provides the junction between the lower leg and the foot (2,3). Displacement of the fragments leads to subluxation of the subtalar joint, and most researchers have recommended open reduction and internal fixation for displaced fractures (2,4–6). The process of open reduction and internal fixation has historically been thought to facilitate revascularization and pre- vent osteonecrosis (2–5). Variable-pitch screws have some biomechanical advantages compared with conventional screws in talus fracture fixation. Posteroanterior-directed fixation was reported to be stronger than conventional anteroposterior fixation using 2 screws (7). Posteroanterior fixation is more likely to cross the fracture site in a perpendicular orientation, which might facilitate compression better than anteroposterior screw fixation. However, posteroanterior screw fixation has some potential disadvantages, including nerve and cartilage damage (8). Anteroposterior screws had an approximately 20% lower yield point and 20% less stiffness than did posteroanterior screws and the blade plate technique, but the difference was not statistically significant (8). Also, variable-pitch screws have biome- chanical advantages compared with conventional screws in talus fracture fixation. Biomechanical testing has shown that headless variable-pitch screws improve fixation of the talar head compared with conven- tional screws (9). Locking plate fixation provides suboptimal stability. Thus, the technique was developed to increase the stability of fixation in the treatment of bone fractures (10–12). The published data contain a limited number of biomechanical studies on talus fractures and have not included any studies comparing locking plate fixation and Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Ahmet Karakasli, MD, Department of Orthopaedics and Traumatology, Dokuz Eylul University Faculty of Medicine, Inciraltı, Izmir 35340, Turkiye. E-mail address: karakasliahmet@gmail.com (A. Karakasli). 1067-2516/$ - see front matter Ó 2015 by the American College of Foot and Ankle Surgeons. All rights reserved. http://dx.doi.org/10.1053/j.jfas.2015.04.002 Contents lists available at ScienceDirect The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org The Journal of Foot & Ankle Surgery xxx (2015) 1–5