Assessment of Magnetic Resonance Imaging Role in Evaluation of Failed Back Surgery Syndrome

Background: Failed back surgery syndrome (FBSS) is a fairly common problem. Magnetic resonance imaging (MRI) with its multi-planar capabilities and superior soft tissue characterization is the modality of choice for imaging the postoperative spine. Objective: This study aimed to investigate the role of MRI in evaluation of FBSS. Methods: Forty-eight patients with FBSS were referred to Zagazig University Hospitals who had previous lumbar spine surgery. All patients were evaluated by history taking and radiological evaluation by dynamic x-ray and a post-operative spine MRI study that consisted of seven series: T1 -weighted sagittal & TI -weighted axial series, a sagittal & axial series for T2-weighted series, post-gadolinium T1-weighted axial and sagittal series and Heavy T2 MRI myelogram. Results: The major identifiable causes of FBSS in operated patients for lumbar disc herniation included recurrent disc herniation and epidural fibrosis (27 and 10.4% of our patients, respectively), and both occurred in 22.9 %, post-operative infected fluid collection in 10.4%, spondylodiscitis in 6.3%, spondylodiscitis with epidural fibrosis in 4.2%, filum terminal ependymoma and postoperative infected fluid collection with epidural fibrosis in 4.2%, postoperative infected fluid collection with spondylodiscitis in 4.2%, epidural fibrosis with spinal stenosis in 4.2%, pseudomeningocele with RDH in 2%, both epidural scar & RDH with deposits in 2% and RDH with spinal stenosis in 2%. Conclusion: MRI is generally a safe and accurate technique, which has been proven to be the technique of choice in evaluation of FBSS with its excellent resolution and multi-planar capabilities.