Abstract
In femoral locked nailing, the distal locking screws is vulnerable to mechanical failure. The stress on these screws is substantially affected by fitness of the nail in the medullary canal. In this study a closed form mathematical model based on elastic column-beam theory is developed to investigate how the nail-cortical contact which is simulated by a linear elastic foundation affects the stress of the distal locking screws. The model is comprised of a construct of a fractured femur with an intramedullay locked nail loaded by an eccentric vertical load. The stress of the locking screw is analysed as a function of the depth of the locking screw in the distal fragment under two situations: with or without nail-cortical contact in the distal fragment. In situation with nail-cortical contact, the screw stress is decreased as the length of nail-cortical contact and the depth of the screw in the distal fragment increases, but this stress contrarily increased when the nail is inserted beyond a certa
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
