There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). There was no significant difference between the 2 groups in the time between admission and operation [42.5 (36.3, 48.0) h for the study group versus 43.0 (28.0, 61.0) h for the control group] ( P=0.870). The median time between the last use of clopidogrel and operation was 55.0 (30.5, 71.0) h. There were no significant differences between the 2 groups in preoperative hemoglobin, operation duration, intraoperative blood loss, rate or amount of perioperative blood transfusion, or rate or amount of wounddrainage ( P>0.05). The rate of general anesthesia was significantly higher for the study group (45.0%, 9/20) than for the control group (18.5%,41/222) ( P=0.012). No complications related to spinal hematoma occurred in the patients receiving spinal anesthesia from the study group. Woundhematoma and subsequent infection occurred in 2 patients from the control group.