Prophylactic antibiotics do not affect cultures in the treatment of an infected TKA: a prospective trial.

UNLABELLED: Prophylactic antibiotics are frequently withheld until cultures are obtained in revision total knee arthroplasty (TKA). We undertook a prospective study to determine whether prophylactic preoperative intravenous antibiotics would affect the results of cultures obtained intraoperatively. We enrolled 25 patients with 26 infected TKAs, a known preoperative infecting organism, and no recent antibiotic therapy. Reaspiration of the infected TKA was performed after anesthesia and sterile preparation. Intravenous antibiotic prophylaxis was then administered and the tourniquet inflated. Intraoperative culture swabs and tissue were obtained at arthrotomy. The timing of events was recorded. Pre- and postantibiotic culture data were analyzed to determine the effect of intravenous preoperative prophylactic antibiotics on cultures obtained intraoperatively. Infections were acute postoperative (four), chronic (19), and acute hematogenous (three). The most common infecting organism was cloxacillin-sensitive Staphylococcus aureus (nine knees [35%]). Preoperative prophylactic antibiotics did not affect the results of intraoperative cultures and we therefore believe should not be withheld before surgery for an infected TKA when an organism has been identified on aspiration preoperatively, and there has been no recent (4 weeks) antimicrobial therapy. LEVEL OF EVIDENCE: Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Failure of the American College of Chest Physicians-1A protocol for lovenox in clinical outcomes for thromboembolic prophylaxis.

A total of 290 consecutive patients who underwent total hip and total knee arthroplasty were prospectively entered into a clinical anticoagulation trial using a 10-day course of Lovenox with the American College of Chest Physicians-1A guidelines. Major complications occurred in 9% of patients; symptomatic deep vein thrombosis occurred in 9 (3.8%) patients, and nonfatal pulmonary embolism in 3 (1.3%) patients. Complications included 4.7% readmissions, 3.4% return to the operating room for wound incision and drainage, 5.1% prolonged hospitalization (wound drainage), and 3.4% injection site complications. Wound drainage of more than 7 days was predictive of readmission and wound reoperation. A body mass index of more than 35 was predictive of prolonged wound drainage. Return to the operating room for wound complications occurred 3x more frequently with the use of Lovenox than in our previous study using warfarin. Surgical site complications requiring readmission or reoperation should be considered "major" complications.