An analysis of bone stresses and fixation stability using a finite element model of simulated distal radius fractures.

A 3-dimensional finite element model was used to study pin fixation in simulated unstable extra-articular distal radius fractures. Bone geometry and material properties were generated from computed tomography. The model was validated in cadaver testing. The model is robust and an accurate predictor of bone stresses and fracture stability under pure axial load. Three different pinning configurations and 3 different pin materials were evaluated. Crossed pinning provided greater fracture stability and a broader distribution of bone stresses than pinning through the radius styloid alone. Steel pins provided greater fracture stability; however, bioabsorbable pins produced lower stress concentration in the bone near the pins. A finite element model is useful in showing differences between various pin constructs in the treatment of distal radius fractures.