Most effective regimen of tranexamic acid in knee arthroplasty: a prospective randomized controlled study in 240 patients.

BACKGROUND: The antifibrinolytic tranexamic acid reduces surgical blood loss, but studies have not identified an optimal regimen. QUESTIONS/PURPOSES: We studied different dosages, timings, and modes of administration to identify the most effective regimen of tranexamic acid in achieving maximum reduction of blood loss in TKA. METHODS: We prospectively studied five regimens (four intravenous, one local; 40 patients each) with a control group (no tranexamic acid). The four intravenous (10-mg/kg dose) regimens included (1) intraoperative dose (IO) given before tourniquet deflation, (2) additional preoperative dose (POIO), (3) additional postoperative dose (IOPO), and (4) all three doses (POIOPO). The fifth regimen was a single local application (LA). Two independent parameters of drain loss and total blood loss, calculated by the hemoglobin balance method, were evaluated statistically. RESULTS: Both parameters were reduced in all five regimens as against the control. A significant reduction in drain loss was seen in the POIO, IOPO, and POIOPO groups whereas total blood loss was significantly reduced in the POIO, POIOPO, and LA groups. The POIOPO group had the least drain loss (303 mL) and least total blood loss (688 mL). The IO group had the greatest drain loss and the IOPO group the greatest total blood loss. CONCLUSIONS: Single-dose tranexamic acid did not give effective results. The two-dose regimen of POIO was the least amount necessary for effective results. When compared against the control, this regimen produced reduction of drain loss and total blood loss, whereas the IOPO regimen did not. The three-dose regimen of POIOPO produced maximum effective reduction of drain loss and total blood loss.

Surgical technique: Lateral retinaculum release in knee arthroplasty using a stepwise, outside-in technique.

BACKGROUND: Lateral release of a tight lateral retinaculum in a TKA is intended to correct patellar maltracking but the widely used inside-out technique has associated risks. We describe an alternate stepwise outside-in technique, with titrated release intended to maximize the chance of preserving the superior lateral genicular artery (SLGA). DESCRIPTION OF TECHNIQUE: Patellar maltracking was judged by a no-thumb technique and graded as I and Ia: normal and near normal tracking; II: patella tilted; III: patella subluxed; or IV: patella dislocated. Outside-in release was performed in three progressive steps. Step-1 release was from the midpatella to the upper tibial border, Step-2 release was from the midpatella to the proximal pole of the patella, and Step-3 release was proximal to the superior pole of the patella with sectioning of the SLGA. METHODS: We retrospectively reviewed records of 1884 patients operated on between 2002 to 2008. Two hundred five patients (11%) had lateral release performed, and 177 of those 205 patients (86%) were reviewed. Patellofemoral function was assessed clinically by The Knee Society score. Radiographs were examined for patellar tilt, shift, and avascular necrosis. The minimum followup was 22 months (median 48 months; range, 22-105 months). RESULTS: The SLGA was preserved in 155 (76%) patients. At last followup, no patient had patellar maltracking, patellar fracture, or avascular necrosis. Six of 177 (3%) patients had anterior knee pain. Female patients and high-flex components had a higher incidence of release and midvastus arthrotomy had a lower incidence of release. CONCLUSIONS: Stepwise release of the lateral retinaculum by an outside-in technique allowed minimum necessary retinacular release, preserving the SLGA in 76% of patients. No complications were seen at followup with functional and radiographic examinations. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.