The strength of fixation of Dwyer screws in seven or eight vertebral
bodies in each of six fresh osteoporotic cadavera was measured under the
following conditions: with fixation with only the screw; with the
staple-screw combination; with each of these modes of fixation combined
with polymethylmethacrylate placed in the hole prior to insertion of the
screw; and with the screw reinserted after failure and filling the hole
with methacrylate. The strength of fixation of the screw-staple combination
was increased almost twofold by the methacrylate, and after failure
followed by reinsertion of the screw embedding it in methacrylate, strong
fixation was restored.