Evidence-based approach of treatment options for postoperative knee pain.

Optimal pain management is critical after knee surgery to avoid adverse events and to improve surgical outcomes. Pain may affect surgical outcomes by contributing to limitations in range of motion, strength, and functional recovery. The causes of postoperative pain are multifactorial; therefore, an appropriate pain management strategy must take into account preoperative, intraoperative, and postoperative factors to create a comprehensive and individualized plan for the patient. Preoperative assessment includes management of patient expectations, recognition of conditions and early counseling for high-risk patients (ie, opioid dependence, psychiatric comorbidities), and use of preemptive analgesia techniques (ie, preoperative IV medications, peripheral nerve blocks, incisional field blocks). Intraoperative strategies include meticulous surgical technique, limiting the use of tourniquets (ie, duration and pressure), and using preventive analgesia methods (ie, postoperative field block, continuous nerve catheters, intra-articular injection). Postoperative analgesia may be facilitated by cryotherapy, early mobilization, bracing, and rehabilitation. Certain modalities (ie, continuous passive motion devices, transcutaneous electrical nerve stimulation units, iontophoresis) may be important adjuncts in the perioperative period as well. There may be an evolving role for alternative medicine strategies. Early recognition and treatment of exaggerated postoperative pain responses may mitigate the effects of complex regional pain syndrome or the development of chronic pain.