Prospective randomized study after the use of drains in total knee arthroplasty with implant.

Objective: to compare the laboratorial results of opening suction drainage 6 hours and 12 hours after total knee arthroplasty surgery.

Methods: prospective and randomized study in 88 patients undergoing with total knee arthroplasty in two groups: in one group the opening suction drainage was performed 6 hours (n = 45) after the surgery and in the other 12 hours (n = 43) after the surgery.

Results: the outcome was a significant fall in the three laboratorial variables (hemoglobin, red blood cells and hematocrit) between the pre and post-operative in the total sample and in the six and 12 hour opening suction drainage groups.