Study design: Retrospective Cohort Study.
Objective: Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) is emerging as a valuable imaging test for identifying pain generators within the lumbar spine. The relationship between radiotracer uptake on SPECT/CT and anatomic biomechanical parameters has not been previously studied.
Methods: We performed a retrospective review of all patients seen at our institution between 2021-2023 who obtained SPECT/CT scans for workup of thoracolumbar back pain. Patient data including demographic, clinical symptoms, and surgical history were collected. Radiology reports were reviewed for evidence of pathologic degeneration and increased bone metabolism on SPECT/CT. Biomechanical parameters were measured from standing scoliosis plain radiographs. Patients were stratified into two cohorts by either presence or absence of asymmetric coronal uptake on SPECT/CT.
Results: 160 patients met inclusion criteria. Patients were primarily male (55%) with average age 55 ± 15 years. 87 (54%) patients demonstrated asymmetric uptake on SPECT/CT. These patients were older (P < 0.001), but with similar gender, prior fusion history, sacroiliitis, adjacent segment degeneration, and pseudoarthrosis (P > 0.05). This cohort had more disc disease, facet arthropathy, and greater degree of coronal scoliosis and coronal imbalance (P < 0.001). There were significantly more sites of uptake in the asymmetric cohort, and uptake was preferentially observed in the concavity of the lumbar curve (P < 0.001). There were no significant differences in sagittal balance or spinopelvic mismatch between cohorts (P > 0.05).
Conclusion: Asymmetric uptake on SPECT/CT was associated with coronal deformity in patients with low back pain. Further prospective studies are warranted to assess the effect of coronal deformity on pain generation.
Keywords: back pain; biomechanics; coronal deformity; lumbar; sagittal deformity; single photon emission computed tomography.