| Abstract: | In a randomized, double-blind, placebo controlled trial, we investigated the postoperative analgesic effect of a single intra-articular injection of 40?mg methylprednisolone acetate (MP) administered 1 week before total knee arthroplasty (TKA). Forty-eight patients with high pain osteoarthritis (≥5 on a numeric rating scale during walk) and sensitization (pressure pain threshold?<250?kPa), aged 50 to 80 years and scheduled for primary unilateral TKA under spinal anaesthesia were included. The primary outcome was the proportion of patients with moderate/severe pain during a 5-m walk test 24 hours postoperatively. Secondary outcomes included pain at 48 hours, during the first 14 days, sensitization (quantitative sensory testing with pressure pain threshold and wind-up from temporal summation), and inflammatory changes (systemic C-reactive protein, intra-articular interleukin [IL]-6). No difference in the proportion of patients with moderate/severe pain was found between MP/placebo groups at 24 hours (67% and 74%, χ2?=?.2, P?=?.63, odds ratio = .7, 95% confidence interval = .2–2.8) or at 48 hours (57% and 68%, χ2?=?.5, P?=?.46, odds ratio = .6, 95% confidence interval = .2–2.3), and no difference between groups in postoperative sensitization was found (P?>?.4) despite reduced preoperative intra-articular inflammation (IL-6) in the MP group versus placebo (median change in IL-6 = ?70?pg/mL, interquartile range = ?466 to 0 vs. 32?pg/mL, interquartile range = ?26 to 75, P = .029). Alternative central or peripheral analgesic interventions in this high-risk group are required.PerspectivePeripherally driven inflammatory pain and nociceptive changes before TKA has been suggested to be a cause for increased acute postoperative pain. However, preoperative intra-articular MP in patients with high pain osteoarthritis and sensitization did not reduce acute post-TKA pain or sensitization despite a preoperative reduction of intra-articular inflammatory markers. |
