Covalently bonding the metal-bone cement interface in orthopedic implants.

摘要

Metal-bone cement interfaces can loosen because there is no chemical bond between the two surfaces. Artificial joints that loosen over time must be surgically replaced. I modified the metal surface by precoating it with 3-methacryloxypropyl trichlorosilane, which contains two functional groups that chemically link the metal to the bone cement. Precoating the metal surface was easily achieved by soaking it in a solution of the trichlorosilane for 2 hours. The resulting monolayer was investigated with ellipsometry, contact angle, and XPS. Mechanical strength of the interface was tested with a novel push-out setup that minimized undesired forces and enhanced reproducibility of test samples. These tests showed an average 112% increase in failure strength with the silane treatment. Push-out tests were performed for samples stored in saline at 37°C for 30 and 60 days, for smooth polished pins, and for pins that were preheated to 60°C before curing in bone cement.