Abstract: Objective  To analyze the effect of two different anesthesia methods on deep vein thrombosis(DVT) and mental state in elderly patients undergoing total knee arthroplasty (TKA). 
Methods  A total of 84 elderly patients with knee osteoarthritis(KOA) who were treated with TKA were divided into two groups: the control group (general anesthesia, n=42) and the observation group(combined spinal and epidural anesthesia, n=42). The levels of nerve growth factor(NGF) and brain derived neurotrophic factor(BDNF) in peripheral blood and the scores of mini-mental state examination(MMSE) were compared before and after operation, and the occurrence of DVT and mental disorder was recorded. 
Results  The levels of NGF and BDNF in the peripheral blood and the MMSE scores of the two groups were reduced initially and then increased, and both reached the lowest point at 1 h after operation. The differences of interaction between groups, time points, and time points between groups were statistically significant(P＜0.05), The incidence of mental disorder within 3 d after operationand DVT within 7 d after operation was significantly lower in the observation group than in the control group(P＜0.05). 
Conclusion  Compared with general anesthesia, combined spinal and epidural anesthesia can effectively reduce the incidence of postoperative DVT in elderly patients with KOA treated by TKA, and has a less impact on their mental state.

Key words: arthroplasty, replacement, knee, anesthesia, venous thrombosis