Background and objectives Data is insufficient to determine whether perioperative statin use increases or decreases postoperative pain. This study aimed to investigate the association between perioperative statin use and pain outcomes after total knee arthroplasty performed under spinal anesthesia.

Methods This is a retrospective, observational study based on medical records from a tertiary hospital between January 2005 and October 2017. Medical records of patients who underwent elective total knee arthroplasty under spinal anesthesia as inpatients were analyzed. Pain outcomes were compared through postoperative day (POD) 3 in patients who were taking statins perioperatively versus patients who were not taking statins.

Results A total of 1088 propensity-matched participants were included in the final analysis (544 patients in the statin group and 544 patients in the non-statin group). The total morphine equivalent consumption through POD 3 was higher in the statin group than in the non-statin group (mean (SD), statin group: 525.4 (119.7) vs non-statin group: 495.3 (115.3), 95% CI of the difference: 15.9 to 44.4, p<0.001). In the linear regression analysis, the total morphine equivalent consumption through POD 3 was 30.14 mg higher in the statin group compared with the non-statin group (95% CI 15.93 to 44.35; p<0.001).

Conclusions Perioperative statin use is associated with a significant increase in postoperative opioid consumption after total knee arthroplasty performed under spinal anesthesia; however, this increase was so marginal that its clinical importance remains controversial.