Baver Acar1, Ozkan Kose2, Yusuf Alper Kati2, Omer Faruk Egerci2, Adil Turan2, Halil Yalcın Yuksel2. 1. Antalya Education and Research Hospital, Department of Orthopaedics and Traumatology, Antalya 07100, Turkey. Electronic address: baveracar@hotmail.com. 2. Antalya Education and Research Hospital, Department of Orthopaedics and Traumatology, Antalya 07100, Turkey.
Abstract
PURPOSE: Scaphoid waist fractures may be fixed through volar or dorsal screw fixation. However, there is no consensus on which surgical fixation method should be performed. The purpose of this study was to compare volar versus dorsal screw fixation of scaphoid waist fractures under physiological loading conditions utilizing finite element analysis. METHODS: A transverse scaphoid waist fracture (Herbert type B2) model was fixed with a headless cannulated compression screw using either a volar or dorsal approach. Displacement and rotation of the fragments and stress analysis on the scaphoid bone and screw were analyzed in the models using 3-D finite element analysis in three different wrist positions; total extension (TE), neutral (N) and total flexion (TF). RESULTS: Displacement of the fracture gap in volar fixation in all planes (x, y, z) was less than in dorsal fixation in the TF and N positions. Furthermore, rotational stability was stronger in volar fixation in all planes and wrist positions. von Mises stress values were concentrated on the proximal fragment in all wrist positions. CONCLUSIONS: Although both volar and dorsal fixation techniques can be preferred in Herbert type B2 fractures, results of this finite element analysis suggest that centrally placed volar compression screw fixation may be biomechanically advantageous over dorsal screw fixation. LEVEL OF EVIDENCE: I.
PURPOSE: Scaphoid waist fractures may be fixed through volar or dorsal screw fixation. However, there is no consensus on which surgical fixation method should be performed. The purpose of this study was to compare volar versus dorsal screw fixation of scaphoid waist fractures under physiological loading conditions utilizing finite element analysis. METHODS: A transverse scaphoid waist fracture (Herbert type B2) model was fixed with a headless cannulated compression screw using either a volar or dorsal approach. Displacement and rotation of the fragments and stress analysis on the scaphoid bone and screw were analyzed in the models using 3-D finite element analysis in three different wrist positions; total extension (TE), neutral (N) and total flexion (TF). RESULTS: Displacement of the fracture gap in volar fixation in all planes (x, y, z) was less than in dorsal fixation in the TF and N positions. Furthermore, rotational stability was stronger in volar fixation in all planes and wrist positions. von Mises stress values were concentrated on the proximal fragment in all wrist positions. CONCLUSIONS: Although both volar and dorsal fixation techniques can be preferred in Herbert type B2 fractures, results of this finite element analysis suggest that centrally placed volar compression screw fixation may be biomechanically advantageous over dorsal screw fixation. LEVEL OF EVIDENCE: I.
Authors: Ludovico Lucenti; Kevin F Lutsky; Christopher Jones; Erick Kazarian; Daniel Fletcher; Pedro K Beredjiklian Journal: J Wrist Surg Date: 2019-10-16
Authors: Jan Kubicek; Filip Tomanec; Martin Cerny; Dominik Vilimek; Martina Kalova; David Oczka Journal: Sensors (Basel) Date: 2019-11-27 Impact factor: 3.576