Fig. 2

Comparison of the mean changes of patients VAS score in the three groups. Statistical significant difference between before and after treatment in each group ^★P < 0.05; Statistical significant difference between treatment group 2 and control group ^&P < 0.05; Statistical significant difference between treatment group 2 and treatment group 1 ^P < 0.05; Compared with the previous time-point of this group ^■ P < 0.05