[Defective shaft positioning in medullary nailing as a result of play of the nail--a biomechanical analysis].

The influence of the nail wall thickness on the stress distribution is shown for the AO-nail as well as the Küntscher-nail. The quality of the analytical solution is proved by demonstrating that the presence of the slot in the nail does not shift the bending stresses merely. The gap between nail and bone is shown to be responsible for misalignments in the fracture.