Imaging persistent spinal pain syndrome and spine surgery complications: an interpretation guide for radiologists

This educational review provides a comprehensive guide for radiologists on the imaging interpretation of persistent spinal pain syndrome (PSPS) and complications following spine surgery. PSPS, previously known as failed back surgery syndrome, describes persistent or recurrent, primarily neuropathic, pain after spine surgery affecting 10-40% of patients. Radiologists often encounter challenges in diagnosing PSPS due to unfamiliarity with postoperative anatomical modifications and the complexity of surgical interventions. This review emphasises the necessity of correlating imaging findings with the clinical context through an interdisciplinary collaboration, while keeping in mind the particular psychological context of postoperative patients in chronic pain. We focus on lumbar spine surgery such as lumbar spine discectomy, lumbar spine stenosis, posterior decompression and stabilisation-fusion procedures. The review offers practical insights into managing key clinical scenarios: early complications with genuine emergencies, but also more subtle diagnoses such as low-grade infections or hardware failures. We underscore the utility of various imaging modalities-radiography, CT, MRI, PET and SPECT, and propose the ideal combination for each clinical situation. Plain radiographs are useful for assessing patients in standing positions and detecting intervertebral instability. CT is ideal for examining bone fusion and surgical hardware, while MRI excels in soft tissue analysis. PET and SPECT provide crucial insights into bone metabolism, detecting micromobility or infections. Based on 15 years of interdisciplinary collaboration, this guide, based on clinical scenarios, aims to enhance radiologists' confidence and accuracy in interpreting postoperative spine imaging, improving diagnostic precision, patient management and communication with referring clinicians. KEY POINTS: Managing postoperative spine imaging is often challenging for surgeons and radiologists. Postoperative spine imaging requires precise clinical correlation and careful multidisciplinary evaluation. Different imaging modalities can be combined to answer difficult issues.