6 randomized controlled trials (495 patients and 564 knees) were used in this systematic review and meta-analysis to determine the efficacy of suction drains in patients undergoing primary total knee arthroplasty (TKA). Outcomes of range of motion, knee swelling, hemoglobin levels, and length of hospital stay were analyzed. Results indicated no significant differences in knee flexion, swelling, and length of hospital stay between 'drain' and 'no drain' groups, raising the possibility that drains may not provide additional benefits following TKA. Further study is needed to verify findings through high-quality RCTs, as well as to examine a wider range of patient outcomes.