Reduction of wear volume from ultrahigh molecular weight polyethylene knee components by the addition of vitamin E.

Wear performance and debris-size distribution of vitamin E (DL-alpha tocopherol, VE)-added ultrahigh molecular weight polyethylene (UHMWPE) was evaluated using a knee-simulator test. VE was mixed with GUR 1050 UHMWPE powder at 0.3 wt%, and the tibial components of the knee joint were made by direct compression molding.

Reliability of cobalt-chromium alloy aneurysm clips after long-term implantations in patients with cerebral aneurysms.

Object: Aneurysm clip reliability after long-term implantation in vivo has not been examined. In this study the authors evaluated the mechanical properties and surface elemental composition of Co-Cr alloy aneurysm clips implanted for more than 10 years in patients with cerebral aneurysms.

Methods: Five aneurysm clips implanted for ruptured or unruptured intracranial aneurysms were retrieved and examined.