Zlotnicki JP, et al. - This study was conducted to compare the effectiveness of periarticular injection using long-acting vs short-acting preparations, with a focus on pain relief, total narcotic usage, and completion of physical therapy goals, specifically range-of-motion. At early and late time points, minimal significant differences were noted between liposomal bupivacaine and plain bupivacaine. A superiority of both preparations of periarticular injection over control pain regimens was noted but in direct comparison, these preparations were equivalent to one another.