Abdullah W. Saleh, BS: No financial relationships to disclose
Introduction: Low back pain (LBP) is a leading cause of disability worldwide. Nearly a third of LBP patients endorse pain of sacroiliac joint (SIJ) origin. Diagnosing SIJ dysfunction (SIJD) remains a critical challenge clinically despite the widespread use of conventional imaging modalities. The use of single-photon emission computed tomography/computed tomography (SPECT/CT) has been hypothesized to aid in identifying lumbar pain generators and guiding surgical decision making. This case series aims to explore SPECT/CT’s ability at predicting successful outcomes one year following SIJ fusion.
Methods: We analyzed electronic health records of seven patients who underwent unilateral SI joint fusion. Data collected included subjective and objective preoperative diagnostic evaluations, post-operative outcomes, and how these findings correlated with patient clinical recovery. Preoperative SPECT-CT imaging was reviewed independently by two authors who graded radiotracer intensity at SI joints relative to iliac crest and vertebral body uptake.
Results: All patients exhibited chronic low back pain and pelvic pain, with brief improvement of pain following diagnostic SI steroid injections. All patients underwent preoperative assessments including lumbar MRI, X-Rays, and SPECT/CT. 0/7 MRI and 2/7 X-ray radiology reports indicated SI joint abnormality. SPECT/CT findings revealed abnormal radiotracer uptake (hot) in 2/7 patients, both of which were the only patients who reported significant reduction in pain one year post operation. Two patients had contradictory X-Ray and SPECT/CT SIJD findings. In both cases, SPECT/CT correlated with pain outcome one year post operation.
Conclusion : SPECT/CT studies resulting in abnormal radiotracer uptake within the SI joint were better predictors of significant pain reduction one year post operation than response to SI joint injections, X-ray, or MRI findings. These results emphasize the clinical utility SPECT/CT in perioperative decision making. Larger cohort studies are needed to confirm SPECT/CT’s predictive value.