This retrospective cohort study with propensity score matching investigated two groups of patients after TKA: the steroid group (n = 50) received an intraoperative corticosteroid PAI (methylprednisolone 40 mg); the non-steroid group (n = 50) did not receive the corticosteroid. To evaluate the APR, C-reactive protein (CRP) levels and erythrocyte sedimentation rates (ESR) were determined preoperatively and on postoperative day (POD) 2, 4, 6, 14, and 28. A visual analogue scale (VAS) was used to measure pain on the night of surgery and on POD 1, 2, 4, and 6. Maximal flexion at discharge (POD 7), morphine equivalent dose (MED), and complications were also evaluated.