Pull-out testing of screws inserted into cement and bone under various
conditions showed that the cement-screw complex was significantly stronger
when the screw was placed in soft cement and the cement was allowed to
polymerize without further manipulation. When screw fixation in
osteoporotic bone was reinforced with cement, the bone was the weakest
component in the system. Fixation under these conditions should be enhanced
by increasing the area of contact between the cement and bone. By cooling
the cement to prolong its working time, it could be injected with a syringe
in such a way that maximum endosteal and periosteal contact was
provided.