[Influence of closed-box and open-box knee prosthesis on postoperative blood loss in patients undergoing total knee replacement].

OBJECTIVE: To study the influence of close-box and open-box knee prosthesis on postoperative blood loss in patients undergoing total knee replacement (TKR).

METHODS: From June 2005 to December 2006, 108 patients with primary knee osteoarthritis were treated with TKR. Closed-box knee prosthesis was used in 54 patients (Group A), including unilateral (Group A1, n=27) and bilateral (Group A2, n=27). There were 7 males and 47 females, aged 41-76 years; and the disease course was 4-16 years. Open-box knee prosthesis was used in 54 patients (Group B), including unilateral (Group B1, n=27) and bilateral (Group B2, n=27). There were 8 males and 46 females, aged from 59-81 years; and the disease course was 8-26 years. The postoperative blood loss and perioperative blood loss were compared between groups.

RESULTS: The postoperative blood loss was (890+/-352), (1,694-/+528), (1,068+/-386) and(2,065+/-622) mL in groups A1, A2, B1 and B2, respectively. There was no significant difference between groups A1 and B1 (P>0.05). There was significant difference between groups A2 and B2 (P<0.05). The total blood loss was (1,095+/-329), (2,082+/-594), (1,274+/-415) and (2,459+/-734) mL in groups A1, A2, B1 and B2, respectively. There was no significant difference between groups A1 and B1 (P>0.05). There was significant difference between groups A2 and B2 (P< 0.05).

CONCLUSION: Closed-box knee prosthesis may play roles on reducing postoperative blood loss. The main influential factor for postoperative blood loss is operation techniques which includes reducing operation time and stanching thoroughly during operation.