Rebound pain after regional anesthesia in orthopedic surgery: current evidence and clinical implications - a narrative review

Regional anesthesia is widely used in orthopedic surgery because it provides effective postoperative analgesia and reduces opioid requirements. However, increasing attention has been directed toward rebound pain, a phenomenon characterized by the abrupt emergence of severe pain following the resolution of a peripheral nerve block. Although frequently reported, rebound pain remains inconsistently defined, and its true incidence and clinical significance are still debated. Current evidence suggests that rebound pain is a multifactorial phenomenon influenced not only by block resolution itself but also by the transition from regional analgesia to systemic pain management. Variability in postoperative analgesic strategies, timing of rescue analgesia, patient expectations, and surgical factors may substantially affect both its occurrence and perceived severity. Differences in definitions and outcome measures across studies further contribute to the wide variation in reported incidence rates. Available data support several potential mechanisms, including the unmasking of ongoing postoperative nociceptive input after block resolution, inflammatory responses related to surgical tissue injury, and, in some cases, central sensitization. Clinical observations also indicate that inadequate multimodal analgesia and failure to anticipate the analgesic transition period may play a major role in the development of severe rebound pain episodes. Current evidence suggests that proactive analgesic planning, scheduled multimodal analgesia initiated before block resolution, intravenous dexamethasone, and prolonged regional anesthesia techniques may reduce the incidence or severity of rebound pain. However, the reported benefits are not consistent across all studies, and some interventions improved early analgesia or prolonged block duration without reducing rebound pain or opioid consumption. Interpretation remains limited by substantial clinical and methodological heterogeneity. Rebound pain appears to represent a complex interaction between physiological nociceptive processes and modifiable perioperative management factors rather than a simple consequence of peripheral nerve block resolution alone. Greater standardization of definitions and outcome measures is needed to better characterize its incidence, mechanisms, and clinical relevance in orthopedic surgery.