Unusual mode of mechanical failure of an AO cannulated self drilling screw. A case report


Published online: Aug 27 2009

Bhushan Sabnis, Ivan Brenkel, David Chesney, Ian Weir

From Queen Margaret Hospital, Dunfermline, Fife, United Kingdom

Abstract

Cannulated AO screws are commonly used for fracture fixation. Mechanical failure of screws has been well reported but this was mainly breakage of the screw head during removal. We report an unusual mode of failure of an AO self drilling cannulated screw which we have not previously experienced, where the screw threads were found to be unravelled during insertion. We also suggest the way to recognise this complication early and how to prevent or deal with it.