Postoperative Imaging of Peripheral Nerves: Review of Surgical Techniques, Expected Findings, and Complications

Peripheral nerve injury is a complex condition that significantly impacts quality of life and often affects young and active individuals. Accurate classification of injury severity using the Sunderland grading system is essential for distinguishing cases amenable to conservative management from those that require surgical intervention. While lower-grade injuries are typically managed conservatively at first, persistent or severe symptoms frequently necessitate surgery. Surgical approaches vary depending on the underlying cause of the nerve injury, including compressive neuropathies, trauma, and neoplastic lesions, and may involve nerve decompression, transposition, neurolysis, nerve repair techniques, and tumor resection. Imaging evaluation with high-frequency US and MRI is fundamental for postoperative peripheral nerve assessment, allowing direct nerve visualization, evaluation of the surgical site and persistent signs of nerve injury, identification of secondary changes such as muscle denervation, and differentiation between the expected postoperative findings and complications. These complications include perineural fibrosis, neuroma formation, incomplete decompression, nerve graft failure, and surgical site collections. It is crucial for radiologists to understand the spectrum of normal postoperative changes and recognize abnormal findings to avoid misinterpretation, optimize patient care, and guide clinical decision making after peripheral nerve surgery. The authors aim to provide a comprehensive review of the main peripheral nerve surgical procedures, with a focus on the surgical techniques, expected postoperative imaging appearances, and spectrum of potential complications.