"The pain has pretty much disappeared," he says.
Still, both he and his doctor Joseph Markenson will be watching this week's Food and Drug Administration hearings with great interest, waiting to see what the government thinks should be done about a group of painkillers that help millions, like Zimmer, but also pose risks.
The issue, as CBS News Correspondent Elizabeth Kaledin reports, is heart disease. Vioxx was pulled off the market in September when studies showed it increased risk of cardiovascular problems.
Now, more studies are emerging. Two, released Monday, also suggest an increased risk associated with other so-called Cox-2 drugs Celebrex and Bextra.
The way patients interpret the findings and what they hear, Markenson says, is that Celebrex causes heart disease or death.
"That's what comes out of this," he says.
So where does the truth lie in that statement?
"We don't know yet," says Markenson. "That's why we need to investigate.
"That's why we need an FDA hearing."
During, the FDA will digest all the new evidence and try to make a decision about and who should be taking them.
Drug safety experts foresee three possible scenarios:
"If there are even a small number of patients who might benefit by having access to these drugs then for that reason it might be worth keeping them on the market," says Wayne Ray, a professor at Vanderbilt University.
Zimmer says he's going to keep taking Celebrex until the government tells him the risks outweigh the benefits.
"All I know is I feel great, and I don't like change," says Zimmer.
Some sort of decision is expected by Friday. It could be one of the toughest rulings the FDA has had to make in a time of intense doubt about whether the agency is adequately protecting the public.