A total of 70 patients with elective unilateral TKA were selected and divided into two groups by random number table: ropivacaine group (R group) and butorphanol combined with ropivacaine group (BR group), 35 cases in each group.
70 patients with unilateral TKA were randomly divided into two groups: Ropivacaine group (R group) and butorphanol combined with ropivacaine group (BR group), with 35 cases in each group.
70 patients with unilateral TKA were selected and randomly divided into two groups: ropivacaine group (R group) and butorphanol combined with ropivacaine group (BR group), with 35 patients in each group.