title: Fixation of Dwyer screws for the treatment of scoliosis. A postmortem study.
abstract: 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.
mesh_terms: D001843:Bone Cements; D001863:Bone Screws; D002102:Cadaver; D006801:Humans; D008768:Methylmethacrylates; D010024:Osteoporosis / Q000150:complications; D012600:Scoliosis / Q000601:surgery*; D013314:Stress, Mechanical
chemical_list: D001843:Bone Cements; D008768:Methylmethacrylates