Biomechanical assessment of fixation methods for segmental mandible reconstruction with fibula in the polyurethane model.

BACKGROUND: A variety of plating techniques are employed by microsurgeons to provide rigid fixation for vascularized bone constructs of the mandible. The aim of this study was to biomechanically compare three commonly utilized plating techniques for rigid fixation of fibula bone flaps in reconstructing lateral segmental mandibular defects. MATERIALS AND METHODS: Polyurethane mandibles with 3-cm segmental defects were reconstructed using polyurethane fibula models. Three fixation techniques were compared (n = 5 models per group): Group 1 used two 2.0-mm miniplates at each osteotomy site, Group 2 used a single 2.3-mm plate, and Group 3 used a single 2.7-mm plate. Biomechanical testing of maximum force and displacement at failure for each plating technique was assessed and statistical comparison performed. RESULTS: The average displacement for Group 1 was 14.08 +/- 1.42 mm, Group 2 was 5.79 +/- 0.89 mm, and Group 3 was 6.03 +/- 1.59 mm. Group 1 had significantly greater (P < 0.05) displacement when compared with Group 2 and 3. Analysis of variance demonstrated the three groups varied significantly in mean displacement (0 < 0.01). The average force before failure for Group 1 was 616.4 +/- 33.83N, Group 2 was 737.8 +/- 72.57N, and Group 3 was 681.0 +/- 67.98N. Group 2 withstood significantly greater force than Group 1 (P < 0.05), and withstood greater force than Group 3, although the difference was not significant. Analysis of variance showed the three groups varied significantly in mean force at failure (P < 0.05). CONCLUSION: Reconstruction using a single 2.3-mm plate provided the best rigid fixation for lateral segmental defects of the mandible. (c) 2016 Wiley Periodicals, Inc. Microsurgery 36:330-333, 2016.