Stress analysis of compression plate fixation and its effects on long bone remodeling.

A three-dimensional finite element model is generated for an intact plexiglass tube with an attached six-hole stainless steel compression plate. The results for a wide range of loads, including cyclic external loads and static tensile preloads in the plate and screws, are examined as specifically related to plate-induced osteopenia. The model demonstrates that disuse osteopenia, resulting from a reduction in magnitude of cyclic axial stress, should be limited to the central region between the inner screws. Also, the addition of a static preload negates any reduced axial stress levels in this region, thus raising questions on the relative importance of static and cyclic stresses for the internal remodeling of bone.