STUDY OF BIOMECHANICAL SCREW PURCHASE PERFORMANCES OF FIVE TYPES OF CORTICAL SCREWS: AN INNOVATIVE MEASUREMENT METHOD

BackgroundFemur fracture fixation systems depend on the stability of the supporting cortical screws, inside the host bone. Only a few works have studied the stability of cortical screws in femur shafts and compared their results with previous studies.MethodsIn present study, five different cortical screw types are assessed using artificial femurs, under equated testing conditions. The maximum force needed to cause screw-bone inter face failure was measured, for each screw type by pullout tests. The obtained results were normalised according to traditional methods and cross-compared. The best performer was searched for and the effect of screw dimensions on the screw performance was investigated. To make the pullout tests solely dependent on screw dimensions, the effect of the bicortical bone thickness was eliminated by equating the conditions of screw insertion.ResultsEvaluation of the test results proved that the non-locking screws with larger diameter and pitch depth required larger pullout forces to be ...