We can think of two reasons why this might happen. There may be others. First, let's review the drug Vioxx®. This nonsteroidal anti-inflammatory (NSAID) is part of a group of
drugs called COX-2 inhibitors. This means they reduce inflammation. At the same time they keep an enzyme (cyclo-oxygenase-2) in the GI tract from causing GI bleeding.
The drug was taken off the market several months ago. Studies showed it increased the risk of stroke and heart attack. Other similar drugs (Celebrex, Arcoxia) are now getting a second look. Research already done by scientists using Vioxx® can still bring valuable
information to doctors and other researchers.
The idea behind the study can be duplicated with these other drugs for comparison. Perhaps Vioxx® itself can't be used, but another drug can for the same effect. Take for example the study you saw. Vioxx® was used to reduce postoperative pain after knee
arthroscopy. A single dose given before the operation had very good results afterwards. The patients had less pain, used fewer narcotics, and got better faster. Other COX-2 inhibitors still available may work the same way.
Second the study was probably sent in and accepted for publication before Vioxx® was taken off the market. Sometimes things like this can't be pulled back in time and the
report goes through. In the publish or perish world, this may still benefit those who spent so much time and effort on a study.