Table 2. Mechanical withdrawal thresholds of rats in normal, knee osteoarthritis, and knee osteoarthritis-antagonist groups.

Group (n=15)	Preoperative	14th day	28th day	42nd day	56th day
	Mean±SEM	Mean±SEM	Mean±SEM	Mean±SEM	Mean±SEM
Normal	12.667±7.090	14.000±9.295	17.833±6.616	12.500±7.148	22.333±5.680
Knee osteoarthritis	13.167±6.706	4.667±2.733**	3.667±1.506**	6.000±2.828**	6.000±2.191**
Antagonist	13.667±6.831	6.333±2.338△	11.167±4.446△△	12.333±4.179△△	15.500±8.526△△
SEM: Standard error of the mean; * p<0.05; ** p<0.01, compared with normal group; △ p<0.05, △△ p<0.01, compared with the knee osteoarthritis group.