Group 1 showed a significantly lower mean VAS score at postoperative 1 , 3 , 6 , 12 , 18 , and 24hours compared with group 2 ( 5.1 < 7.6 , 4.4 < 6.3 , 3.7 < 5.3 , 3.2 < 4.5 , 2.7 < 4.0 , and 2.7 < 3.4 , respectively ) .