Azim S, et al. - In this prospective observational study, researchers investigated the impact of perioperative cytokine levels after total knee arthroplasty (TKA) surgery upon postoperative pain. In this work, preoperative chronic pain was suggested to be a predictor of the severity of acute postoperative pain, while, the pre- and post-operative inflammatory status failed to predict postoperative pain in TKA patients.