Introduction and Objectives: The use of aspiration drainage in knee replacement is associated with an increase in postoperative bleeding. We assessed the affectivity of a 4 hour delayed opening of the drainages.

Materials and Methods: Retrospective comparative study. We studied 122 cases divided into 2 groups that underwent total knee replacement with different guidelines for drainage opening during the postoperative period. In one group the drainage was opened immediately, in the other after a 4 hour delay. We assessed the amount of fluid drained and also possible modifying factors. We also assessed associated complications.

Results: We found significant differences in the amount of fluid drained between the drainages opened immediately and at 4 hours. With the use of drainage opened at 4 hours there is a non-significant decreasing trend in the need for transfusions; there is no significant increase in local complications at the wound site or at the site of the arthroplasty.

Discussion and Conclusions: Keeping drainages closed during the first 4 hours of the postoperative period is a cost-effective way of decreasing bleeding in TKR surgery.

Introduction and Objectives: Currently it has become popular to use cement impregnated with antibiotics in revisions of septic total knee replacements. However, the use of cement with antibiotics in primary knee arthroplasties continues to be a cause of controversy. However, contrary to American opinion, in some European studies it has been seen that the use of cement with antibiotics decreases the infection rate in primary knee arthroplasties.

Materials and Methods: We hereby present a comparative study of 642 patients that underwent primary total knee replacement (TKR) (Legacy-Zimmer) between 2003 and 200. We divided the patients into 2 groups. One group of 296 patients underwent primary TKR using cement without antibiotic. A second group of 346 patients underwent primary TKR using gentamycin-loaded cement. Mean follow-up was 1 year. Our aim was to find differences in postoperative infection rates during the first year of follow-up

Results: We found no differences in demographic variables, operation time, ischemia time, rate of transfusions, days of hospitalization or medical complications. We saw 10 infections (3.3% infection rate) in group 1. We saw 3 infections (0.09 % infection rate) in group 2. We carried out a comparative statistical analysis and it was significant.

Discussion and Conclusions: Cement impregnated with gentamycin is effective in the prevention of deep infection in the short and medium term in primary total knee replacement.