Influence of Assembly Force and Distraction on the Femoral Head-Taper Junction.

Background: This study investigates if the placement of femoral heads (trials and actual implants) using varying impaction forces causes physical compromise to the trunnion.

Methods: Trunnion and head taper wear patterns were evaluated after impaction and removal of new femoral stem trunnions and ceramic heads at various impaction loads (2 kN, 4 kN, or 6 kN, n = 6/group). In addition, trunnion wear patterns were measured after plastic trials were hand-placed on new trunnions and underwent range of motion testing in a Hip Simulator (n = 5).

Predicting polymer nanofiber interactions via molecular simulations.

Physical and functional properties of nonwoven textiles and other fiberlike materials depend strongly on the number and type of fiber-fiber interactions. For nanoscale polymeric fibers in particular, these interactions are governed by the surfaces of and contacts between fibers. We employ both molecular dynamics (MD) simulations at a temperature below the glass transition temperature T(g) of the polymer bulk, and molecular statics (MS), or energy minimization, to study the interfiber interactions between prototypical polymeric fibers of 4.