The control group is going to be given celecoxib 200mg/24h to 2 weeks after operation.On the basis of the above scheme, the treatment group is going to receiving duloxetine 60mg/24h to 8 weeks after operation.HAMD-17 scale, KSS scale, SF-36 scale and WOMAC scale will be used to evaluate the two groups before and after operation for 4 and 8 weeks.