Dose Comparison of Flowable Gelatin Hemostatic Matrix for Bleeding Loss in Primary Total Knee Arthroplasty.

Introduction Intraoperative and postoperative bleeding in total knee arthroplasty (TKA) affects postoperative outcomes. Although the hemostatic effect of a flowable gelatin hemostatic matrix (FGHM) is known across several surgical fields, its effectiveness on TKA remains controversial. This study aimed to compare the amount of bleeding across three groups treated with different doses of FGHM in TKA. Methods Overall, 122 knee joints of patients who underwent unilateral primary TKA were included and divided into three groups according to FGHM dose: absence of FGHM (control group, N=48), administration of 5 mL of FGHM (5 mL group, N=46), and administration of 8 mL of FGHM (8 mL group, N=38). Total hemoglobin (Hb) loss, drain output, hidden blood loss (HBL), calculated total blood loss (TBL) on the first postoperative day (POD1) and one week postoperatively (POD7), postoperative flexion angle at one week and discharge, and incidence of postoperative deep venous thrombosis (DVT) were assessed. Results At POD1, the mean total Hb losses were 6.3±3.1g (control group), 5.5±3.3g (5 mL group), and 5.3±2.5g (8 mL group), with no significant differences. At POD7, the mean Hb losses were 9.1±4.6g (control), 8.7±3.6g (5 mL), and 8.3±4.0g (8 mL), also with no significant differences. Mean drain outputs and HBLs showed no significant differences among groups. While there was a decreasing trend in TBL with higher FGHM doses, it was not statistically significant at either POD1 or POD7. There were no statistically significant differences in the mean postoperative flexion angle at POD7 or discharge among the groups (99.7±12.6°, 95.7±12.5°, 98.3±13.8° at POD7; 115.9±9.7°, 113.8±9.6°, 116.6±9.2° at discharge). Of these, only one patient in the 8 mL group developed proximal DVT. Conclusion Despite a trend towards decreased bleeding with FGHM, no significant differences were found among the three groups. However, the clinical utility of this hemostatic agent for reducing blood loss after primary TKA remains still unclear.