Tranexamic Acid and Computer-Assisted Surgery in Cemented and Cementless Total Knee Arthroplasty: Are the Effects Additive for Blood Conservation?

INTRODUCTION: Efforts continue to minimize blood loss associated with total knee arthroplasty (TKA). The primary objective of this study was to determine whether computer-assisted surgery (CAS) and tranexamic acid (TXA) were additive in minimizing blood loss in cemented TKA. The secondary objective was to assess the combined effectiveness of CAS and TXA in cementless TKA.

MATERIALS AND METHODS: A retrospective study of 393 consecutive primary TKAs with cemented and cementless fixation was performed. Cemented and cementless fixation TKA cohorts were divided into three subgroups: (1) neither CAS nor TXA was used, (2) CAS alone was used, or (3) CAS plus TXA was used. Three blood loss metrics were calculated: (1) postoperative change in hemoglobin, (2) total drain output, and (3) calculated total blood loss.

RESULTS: After exclusions, 267 cemented TKAs and 35 cementless or hybrid TKAs were available for analysis. In cemented TKAs, the mean postoperative hemoglobin decrease was 2.9 g/dL in patients without CAS or TXA, 2.5 g/dL in the CAS only group, and 2.1 g/dL in the CAS and TXA group (p = 0.001). Median total drain output was lower in the CAS plus TXA group (230 ml) compared to the CAS alone (442.5 ml), and the neither CAS nor TXA group (620 ml) (p = 0.001). Mean calculated total blood loss was 1258.7 ml in the group with neither CAS nor TXA, 1023.8 ml in CAS alone, and 869.1 ml for both the CAS and TXA group (p = 0.001). In cementless TKA, the postoperative hemoglobin drop decreased from 3.3 g/dL in the neither CAS nor TXA group to 2.5 g/dL with CAS alone and 1.9 g/dL in the CAS plus TXA (p = 0.024). Mean total drain output progressively declined with CAS alone and for those with CAS plus TXA compared to those without CAS or TXA (p = 0.004).

CONCLUSIONS: An encouraging additive decrease in blood loss after TKA can occur with utilization of both CAS and TXA. The additive effect of both modalities appears to exist in cemented and cementless fixation techniques. Whether this blood conservation will result in improved patient outcomes remains unknown and should be the topic of further study.