[A prospective randomized study of wound drainage versus non-drainage in primary total hip or knee arthroplasty].

PURPOSE OF THE STUDY

Drainage of the operative wound following total hip or knee replacement (THR, TKR) is usually performed to avoid hematoma formation. A certain amount of blood is lost through the drain. The necessity of wound drainage has been questioned, with a view towards blood saving, although most surgeons have not abandoned drainage for fear of local complications. A prospective randomized study was undertaken to compare drainage and non-drainage following THR/TKR in terms of blood-saving and local complications.

MATERIAL AND METHODS

A total of 256 patients undergoing primary THR (152) or TKR (104) were randomly allocated to undergo either suction drainage or no drainage of the wound: there were 76 drained and 76 non-drained THR's, 52 drained and 52 non-drained TKR's. Blood loss was calculated in each patient from the postoperative drop in hematocrit values; the amounts of blood lost intra-operatively and in the drain were also recorded, as was the number of blood units transfused in each patient. Swelling, hip or knee range of motion and wound healing were monitored over the first 6 weeks after operation, and any local or systemic complication was recorded.

RESULTS

No significant difference was noted between drained and non-drained THR's/TKR's regarding swelling, recovery of hip or knee motion, wound healing, other local or systemic complications. Following THR, no significant difference was noted between calculated blood losses or transfusion requirements in drained versus non-drained patients. Patients with drains lost on average 1 942 ml of blood versus 1 766 ml for non-drained patients; they received on average 1.18 units of transfused blood versus 1.32 units for patients without drains. The differences are not significant. Following TKR, total blood loss was significantly higher in non-drained than in drained patients (1 983 ml versus 1 590 ml) and the amount of blood transfused was also significantly higher in non-drained patients (0.98 unit versus 0.54 unit).

CONCLUSION

Following primary hip or knee arthroplasty, the use of wound drainage did not lead to increased blood loss, and non-drainage did not lead to significant wound healing problems but did not reduce blood loss and transfusion requirements. It was even associated, following TKR, with greater blood loss and transfusion. Such data may therefore be used to support drainage as well as non-drainage following THR or TKR. Avoiding drainage may be interesting in terms of cost, but the benefit is marginal; it also eliminates one possible source of retrograde wound infection. Systematic wound drainage following THR or TKR is essentially a tradition. This study shows that it can safely be dispensed with in a number of cases.