Optimal alignment of the distal screws in the tibial nailing

摘要

Serious stress concentration around the regions near the distal nail-holes and the distal screws in conventional tibial interlocking nails has been reported in previous studies. A three-dimensional finite element model was used to study the interlocking nail, the fractured tibia and the locking screws. The distal screws were inserted into the tibial nail in different configurations. We found that the maximal tensile stress of the nail-screw system can be substantially decreased with the two distal screws configured in the anterior to posterior direction. In a distal or comminuted diaphyseal fracture of the tibia, the optimal alignment of the two distal screws was in the anterior to posterior direction and the nail-screw system with this alignment can bear greater loading in the more demanding fracture patterns.