Impact of 99mTc-methylene diphosphonate single photon emission computed tomography/computed tomography on management and clinical outcomes in patients with failed back surgery syndrome

Background Failed back surgery syndrome (FBSS), defined as persistent or recurrent back pain after spine stabilization surgery (SSS), presents substantial diagnostic and therapeutic challenges with significant healthcare and socioeconomic burden. Anatomical imaging modalities often yield inconclusive findings. The aim of this study is to evaluate the impact of Technetium 99m Methylene Diphosphonate ( 99m Tc-MDP) Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) bone scintigraphy on management decisions and identify predictors of clinical outcomes in terms of changes in the Visual Analog Scale (VAS) and Oswestry Disability Index following interventions in these patients. Results Fifty-four patients (mean age: 51.02 ± 10.59 years) were enrolled. SPECT/CT demonstrated significantly higher detection rates of pain generators compared to planar imaging (96.3% vs. 83.3%, p = 0.001). Cases with high tracer uptake showed significantly more frequent combined screw and facet joint involvement (65.5%, p ≤ 0.001). SPECT/CT findings modified management in 66.7% of the patients studied. Significant progressive improvements were observed in both VAS scores (from 2.98 ± 0.14) and ODI scores (from 49.2 ± 7.8) pre-intervention to (1.10 ± 0.46, p < 0.001) and (20.56 ± 5, p < 0.001), respectively, in the 6 th month post-intervention. Intensity of tracer uptake on SPECT/CT was a significant independent predictor for both pain improvement (OR = 2.10, 95% CI [1.22–3.63], p = 0.007) and disability reduction (OR = 2.08, 95% CI [1.23–3.52], p = 0.006). Conclusions 99m Tc-MDP SPECT/CT meaningfully influences clinical management in patients with post-SSS persistent/recurrent back pain. Intensity of tracer uptake is a significant independent predictor of positive clinical outcomes.