Fracture studies on a mammalian semicircular canal

Abstract

In the present work the pressures necessary to fracture the semicircular canal of the mammalian inner ear, specifically the squirrel monkey, have been investigated experimentally. The results indicate that individual canals can fracture when subjected to internal pressures of approximately 1.6 +/- 0.4 MPa. Simulation testing using Plexiglas and polycarbonate specimens, to represent the location of a possible osteoclast site within the bone forming a semicircular canal, demonstrates further that fracture of the canal can be initiated at this or even lower pressures when the pressure is generated within a simulated osteoclast site. These results provide useful information for a better understanding of the mechanisms by which bubble nucleation and growth could cause pressures of this magnitude within an osteoclast cavity during the decompression phase of a diving schedule. Animals *Atmospheric Pressure Decompression Diving Fractures/*etiology Microscopy, Electron, Scanning Osteoclasts/ultrastructure Saimiri Semicircular Canals/*injuries/physiology Stress, Mechanical Support, Non-U.S. Gov't