Seven studies including a total of 546 patients undergoing primary total knee arthroplasty (TKA) were included in this meta-analysis comparing dexmedetomidine as an adjunct to local anesthesia in nerve blockade or local anesthesia alone. The primary outcomes of interest included the pooled pain scores at rest and during motion. Secondary outcomes of interests included pooled opioid consumption, analgesia duration, patient satisfaction, motor strength, degree of sedation, risk of post-operative nausea and vomiting, and total complications. Studies assessed outcomes within the first 2 days post-operation. Pooled pain scores, both at rest and during motion, were statistically significantly in favour of the dexmedetomidine group at 6, 12, 24, and 48 hours post-operation (p<0.05 for all). Pooled opioid consumption 24 hours post-operation (p<0.001), analgesia duration (p<0.001), patient satisfaction (p<0.001), motor strength (p=0.04), and sedation degree at 24 hours (p<0.001) and 48 hours (p<0.001) post-operation were statistically significantly in favour of the dexmedetomidine group. No statistically significant differences in the pooled risk of nausea and vomiting (p=0.14) or total complications (p=0.89) were observed between the two groups.