The Effects of Mucoperichondrial Flap Elevation on Septal L-Strut Cartilage: A Biomechanical and Histologic Analysis in a Rabbit Model

Background: The harvesting of septal cartilage following mucoperichondrial flap elevation has almost become a standard step in rhinoplasty. However, the strength of the remaining septum has not yet been evaluated. In the current experimental study of a rabbit rhinoplasty model, the remaining septum following a graft harvest was analyzed both biomechanically and pathologically. Methods: Forty New Zealand rabbits were classified into four equal groups. Group 1 consisted of the animals in which unilateral elevation of the mucoperichondrial flaps was undertaken before the graft harvest, group 2 consisted of the animals in which bilateral elevation was undertaken, group 3 included the animals where the septum was exposed and left untouched after a bilateral mucosal flap elevation, and group 4 was designated as the control group. Specimens were analyzed under light microscopy for multiple parameters. Biomechanical analyses were performed with a universal testing device at the Department of Engineering, Biomechanical Laboratories, Istanbul Technical University. Results: Biomechanical analysis in terms of maximum tension revealed significant results among the groups (p = 0.008). Although insignificant results were observed overall using a pathologic analysis, the amount of chondrocytes was lower in group 2 than in group 1 (p = 0.099). The amounts of matrix collagen (p = 0.184) and fibrosis were (p = 0.749) higher in group 2 than in group 1. Conclusions: From these data, the authors conclude that mucoperichondrium integrity plays a crucial role in the biomechanical strength of the septum. More sophisticated studies with further pathologic analysis are required to determine the exact mechanism of strength loss observed with mucoperichondrial flap elevation.