[Tranexamic acid reduces haematomas but not pain after total knee arthroplasty]

Tranexamic acid (TxA) reduces total blood losses (TBL) and allogenic transfusion (TH) after total knee arthroplasty (TKA). TBL can be external (surgical field, drains), or hidden (haematomas). Haematomas induce pain and limit postoperative rehabilitation. The aim of the study was to evaluate if TxA reduces haematomas and pain after TKA.

Prospective non-randomized study.

After ethical committee approvement and written informed consent, the patients planned for a primary TKA were included (control group followed by a TxA group, 15 mg/kg before incision and at skin closure). General anaesthesia and analgesia were standardized (sciatic block, continuous femoral block, ketamine, ketoprofene, paracetamol, PCA with morphine). Volume of haematomas=TBL (calculated based on haemograms performed the day before surgery, and at postoperative day 5, and on transfusions)-measured external bleeding. Patients were followed up for 8 days, and at postoperative day 180 (by phone). Fifty patients per group allowed the detection of a 50% morphine sparing at day 8 (α=0.05 and β=0.2), and a 25% reduction of haematoma volumes at day 5.

Perioperative data, pain scores and functional parameters (until day 180) were not different between control group patients (n=52) and TxA group patients (n=55): morphine consumption at day 8 was respectively 35 ± 32 and 42 ± 38 mg (P=0.29). Yet, TxA reduced hematoma volumes (526 ± 202 versus 337 ± 165 mL of red blood cells, P<0.0001) and clinically apparent hematomas. Morphine consumptions at day 8 and haematoma volumes were not correlated.

After TKA, TxA reduces the volume of hematomas, without any improvement in analgesia and rehabilitation until the sixth postoperative month.