This systematic review and meta-analysis included five randomized controlled trials with 432 patients undergoing total knee arthroplasty. It compared the addition of magnesium sulfate to peripheral analgesic cocktails versus standard cocktails alone. Outcomes of interest included postoperative pain scores (VAS), opioid consumption, time to rescue analgesia, range of motion, mobilization distance, and length of hospital stay. Pooled results showed that magnesium sulfate significantly reduced pain scores and opioid use while enhancing functional recovery during the early postoperative period. No significant increase in complications was observed. These findings suggest that magnesium sulfate is a beneficial adjunct for pain management in total knee arthroplasty.