Use of a haemostatic matrix does not reduce blood loss in minimally invasive total knee arthroplasty

BACKGROUND: Blood loss can increase morbidity and the risk of transfusion after total knee arthroplasty (TKA). This study evaluated the difference in blood loss between minimally invasive TKA performed with and without intra-articular use of a haemostatic matrix (Floseal®). MATERIALS AND METHODS: We retrospectively compared matched pairs in two groups (76 patients in each group): one group received conventional haemostasis (with bovie electrocoagulation), the other group was treated with an intra-articular haemostatic matrix (HM) as an adjunct to electrocoagulation. The outcomes compared were haemoglobin (Hb) and haematocrit levels at days 2 and 4 after surgery as a surrogate for blood loss, transfusion rate, surgical time, preoperative and postoperative range of motion (ROM) at days 21 and 42 and length of stay (LOS) in hospital. RESULTS: No differences were observed for Hb levels at day 2 or day 4 between men in the two groups. In women, however, the mean Hb at day 2 was 11.1 g/dL (SD 1.3) for TKA with HM and 12.0 g/dL (SD 0.9) for TKA without HM (p<0.001), while that at day 4 was 10.6 g/dL (SD 1.3) for TKA with HM and 11.4 g/dL (SD 1.2) for TKA without HM (p<0.001). The haematocrit was higher for TKA without HM at day 2 (p=0.001) and day 4 (p=0.008). The transfusion rate for TKA with HM was 2.6% and for TKA without HM 0% (p=0.497), while the mean surgical time was 93 minutes (SD 12) vs 87 minutes (SD 14), respectively (p=0.0055). There were no differences in preoperative or postoperative ROM at days 21 and 42 between the two groups. The LOS was longer for TKA with HM than for TKA without HM (4.5 days and 4 days, respectively, p=0.011) influenced by the longer stay for the transfused patients. DISCUSSION: The present study showed that the use of Floseal had no effect on reducing either visible or hidden blood loss after TKA, as assessed by a drop in Hb or haematocrit and that hidden blood loss was more important in women treated with the HM.