Unipolar vs bipolar hemostasis in total knee arthroplasty: a prospective randomized trial.

The purpose of this study was to investigate whether unipolar or bipolar hemostasis is more effective in reducing blood loss associated with primary total knee arthroplasty. We randomized 113 consecutive patients undergoing primary total knee arthroplasty into unipolar and bipolar hemostasis treatment groups. The mean postoperative drain output in the unipolar group was 776.5 mL compared with 778.7 mL and was not statistically significant (P = .97). There were no statistically significant differences in postoperative day 1 through 3 hemoglobin level (P = .2-.6) or hematocrit (P = .17-.46) values. The transfusion requirement in the unipolar group was 36% and 40% in the bipolar group (P = .67). Use of bipolar sealer compared with standard unipolar electrocauterization showed no significant difference in postoperative drain output, postoperative hemoglobin level and hematocrit values, or transfusion requirements.