Pain control after knee replacement requires analgesia to both the top (anterior) and bottom
(posterior) portion of the the knee. Presently we use a nerve block for the anterior portion.
The investigators want to to examine if giving Exparel into the posterior portion will give
better pain relief.
Hypothesis: There is no difference in, the use of analgesics or the length and quality of
analgesia and no decrease in the time to be able to accomplish simple to complex knee
movements using Exparel infiltration when compared to controls.