Effects of cable tightening load on the stability in a plate-cable fixation of oblique femoral fractures

Internal cable fixation aims to provide stability of fractured bone to avoid movement which could result in loosening of the implant and a delay in healing, especially for periprosthetic bone fractures. The current study investigated the effect of the cable tightening loads on stability of fractured bone with internal cable fixation. A finite element model of a fractured femur having a 45° medially down-cutting fracture was created and subjected to three tightening loads steps: 200, 300 and 400 N. The higher cable tightening load brought about better stabilization for fixed bone. The higher cable tightening load caused the fracture interface to rotate anterolateral about the femoral shaft axis. Fracture interface dislocation was observed larger in anterior-posterior direction rather than other directions. Using a tension-dislocation equation extrapolativley derived from results cable tensions of 460–550 N are expected to provide fixation stability in both rotational and translational aspects.