Murphy WM, Leu D: “Types of Bone Screws: Modes of Failure,” in AO Principles of Fracture Management, edited by TP Ruedi, WM Murphy, p 159, AO Publishing, Davos, Switzerland, 2000.
Ramsey PL, Hamilton W: Changes in tibiotalar area of contact caused by lateral talar shift. J Bone Joint Surg Am 58: 356, 1976.
Markolf KL, Jackson SR, McAllister DR: Syndesmosis fixation using dual 3.5 mm and 4.5 mm screws with tricortical and quadricortical purchase: a biomechanical study. Foot Ankle Int 34: 734, 2013.
Stuart K, Panchbhavi VK: The fate of syndesmotic screws. Foot Ankle Int 32: 519, 2011.
McBryde A, Chiasson B, Wilhelm A, et al: Syndesmotic screw placement: a biomechanical analysis. Foot Ankle Int 18: 262, 1997.
Kukreti S, Faraj A, Miles JN: Does position of syndesmotic screw affect functional and radiological outcome in ankle fractures? Injury 36: 1121, 2005.
Dar FH, Meakin JR, Aspden RM: Statistical methods in finite element analysis. J Biomech 35: 1155, 2002.
Walke W, Paszenda Z, Kaczmarek M: Biomechanical analysis of tibia: double threaded screw fixation. Arch Materials Sci Eng 30: 41, 2008.
Erkmen E, Simsek B, Yucel E, et al: Three-dimensional finite element analysis used to compare methods of fixation after sagittal split ramus osteotomy: setback surgery-posterior loading. Br J Oral Maxillofac Surg 43: 97, 2005.
Gray HA, Taddei F, Zavatsky AB, et al: Experimental validation of a finite element model of a human cadaveric tibia. J Biomech Eng 130: 031016, 2008.
Haraguchi N, Armiger RS, Myerson MS, et al: Prediction of three-dimensional contact stress and ligament tension in the ankle during stance determined from computational modeling. Foot Ankle Int 30: 177, 2009.
Attarian DE, McCrackin HJ, DeVito DP, et al: Biomechanical characteristics of human ankle ligaments. Foot Ankle 6: 54, 1985.
Beumer A, van Hemert WL, Swierstra BA, et al: A biomechanical evaluation of the tibiofibular and tibiotalar ligaments of the ankle. Foot Ankle Int 24: 426, 2003.
Stauffer RN, Chao EY, Brewster RC: Force and motion analysis of the normal, diseased, and prosthetic ankle joint. Clin Orthop Relat Res 127: 189, 1977.
Fowlkes WY, Creveling CM : Analysis of Variance: Engineering Methods for Robust Product Design Using Taguchi Method in Technology and Product Development, p 312, Addison-Wesley Publishing Co, Boston, 2000.
Hansen M, Le L, Wertheimer S, et al: Syndesmosis fixation: analysis of shear stress via axial load on 3.5-mm and 4.5-mm quadricortical syndesmotic screws. J Foot Ankle Surg 45: 65, 2006.
Thompson MC, Gesink DS: Biomechanical comparison of syndesmosis fixation with 3.5- and 4.5-millimeter stainless steel screws. Foot Ankle Int 21: 736, 2000.
Markolf KL, Jackson S, McAllister DR: Force and displacement measurements of the distal fibula during simulated ankle loading tests for high ankle sprains. Foot Ankle Int 33: 779, 2012.
van den Bekerom MP, Hogervorst M, Bolhuis HW, et al: Operative aspects of the syndesmotic screw: review of current concepts. Injury 39: 491, 2008.
Reggiani B, Leardini A, Corazza F, et al: Finite element analysis of a total ankle replacement during the stance phase of gait. J Biomech 39: 1435, 2006.
Chen WP, Tang FT, Ju CW: Stress distribution of the foot during mid-stance to push-off in barefoot gait: a 3-D finite element analysis. Clin Biomech 16: 614, 2001.
Xu C, Zhang MY, Lei GH, et al: Biomechanical evaluation of tenodesis reconstruction in ankle with deltoid ligament deficiency: a finite element analysis. Knee Surg Sports Traumatol Arthrosc 20: 1854, 2012.
Zhang MY, Xu C, Li KH: Finite element analysis of nonanatomic tenodesis reconstruction methods of combined anterior talofibular ligament and calcaneofibular ligament deficiency. Foot Ankle Int 32: 1000, 2011.
Alonso-Vazquez A, Lauge-Pedersen H, Lidgren L, et al: Initial stability of ankle arthrodesis with three-screw fixation: a finite element analysis. Clin Biomech 19: 751, 2004.
Anderson DD, Goldsworthy JK, Li W, et al: Physical validation of a patient-specific contact finite element model of the ankle. J Biomech 40: 1662, 2007.
Hou SM, Hsu CC, Wang JL, et al: Mechanical tests and finite element models for bone holding power of tibial locking screws. Clin Biomech 19: 738, 2004.
Screw fixation of syndesmotic injuries facilitates ligament healing and restoration of ankle stability, but failure of the screw might threaten the success of the treatment. Screw design parameters, such as outer diameter, inner diameter, thread pitch, leading edge radius, trailing edge radius, leading edge angle, and trailing edge angle, might have effects on the stresses that occur in the screws. This is the first study, to our knowledge, to investigate which geometric screw parameters play key roles in stresses that occur in screws used for syndesmotic fixation.
A three-dimensional finite element model of an ankle was reconstructed. Four different types of titanium screws—4.5-mm malleolar, 4-mm cancellous, 4-mm machine, and 3.5-mm cortical—were placed on this model. Physiologic load was applied to evaluate the stress in the screw. Then the contribution of each design factor to stress in the screws was analyzed systematically by Taguchi's robust design method.
The maximum equivalent ductile failure (von Mises equivalent stress) value was found in the 4-mm cancellous screw (402 MPa). Taguchi's analysis showed that the descending order of contribution of the design factors to stress emerging on the screw is inner diameter, leading edge angle, thread pitch, outer diameter, and trailing edge angle.
Stress that occurs in syndesmotic screws is closely related to their geometry and dimensions. According to the results, a 3.5-mm cortical screw with the ideal screw design regarding optimal parameters to resist against stresses in the syndesmosis seems more reasonable to choose in syndesmotic fixation.