Drainage systems may be used to drain fluid, mostly blood, from surgical wounds after an operation. The drains can either be open or closed. Closed drains use vacuum bottles and plastic conduits to draw fluid away from the wound by producing a negative pressure. They have been evaluated within trials for a number of elective and emergency orthopaedic operations. Closed surgical drainage systems reduce the need for reinforcement of the dressing and bruising around the wound, but increase the need for blood transfusion. Wound drains do not appear to have any effect on the occurrence of wound infections, large blood collections within the wound (haematomas), or the need for additional surgery to correct wound healing complications.
Closed suction wound drains in orthopaedic surgery are of doubtful benefit.