The utility of vancomycin powder application into the surgical site has recently shown efficacy in decreasing infections in patients undergoing thoracolumbar spine surgery. The effect on polyethylene wear after intraoperative placement of vancomycin powder at the surgical site of total joint replacements has not been determined. The purpose of this study is to compare wear behavior of material couples of Cobalt Chromium Alloy (CoCr) on ultra high molecular weight polyethylene (UHMWPE) to identical wear couples with vancomycin powder added prior to the start of wear simulation. A custom-designed six-station wear simulator was used to establish Introduction
Methods
Total joint arthroplasty is one of the most common procedures performed in orthopaedic surgery. Over 600,000 total hip and total knee replacements are performed in the United States each year. At our 550 bed tertiary care facility, 437 total knee arthroplasties were performed in 2010 and 426 in 2011. Tranexamic acid is an antifibrinolyic synthetic derivative of aminocaproic acid used to prevent hemorrhage in patients undergoing surgical procedures. Several studies show decreased blood loss in patients receiving both intravenous and topical tranexamic acid. Beginning in 2011, our surgeons began using topical tranexamic acid in an irrigation solution of 3 grams in 100 mL of normal saline after implant placement and prior to closure of the incision. Our study is a retrospective review comparing patients receiving total knee arthroplasties before and after the institution of tranexamic acid. The purpose of our study was to assess estimated perioperative blood loss, determining the cost effectiveness of using tranexamic acid while comparing adverse effects of using topical tranexamic acid in total knee arthroplasty. Our study includes 683 primary total knees, 373 that received did not receive topical tranexamic acid and 310 that did, from January 1, 2010 to October 31, 2011. There were no demographic differences between the 2 groups. Topical tranexamic acid significantly (p<0.0001) decreased blood loss in patients receiving primary total knee arthroplasties. There were no differences between groups in thromboembolic events or joint infections. Tranexamic acid significantly (p<0.0001) decreased both blood bank cost and total cost of stay resulting in nearly $1,500 savings per patient to our institution.
We reviewed 194 revision arthroplasties of the hip and knee performed over a ten-year period. The results of intraoperative Gram staining were available in 169 (87%). Thirty-two were found to be infected (11 hips and 21 knees) and 137 had no evidence of infection. Intraoperative Gram staining was negative in all 169 cases. The method therefore had a sensitivity of 0% for detecting infection. We conclude that the absence of organisms on intraoperative Gram staining during revision arthroplasty does not confirm the absence of infection.
