Cervical Multifidus Fatty Degeneration and Bony Foraminal Stenosis Are Associated with Unsuccessful Response to Stellate Ganglion Block in Cervical Radicular Pain: A Retrospective Study

Background and Objectives: Ultrasound-guided stellate ganglion block is a promising alternative intervention for cervical radicular pain. However, factors associated with treatment responses remain unknown. This single-center, retrospective study aimed to identify clinical and radiological factors associated with treatment response to stellate ganglion block in patients with cervical radicular pain. Materials and Methods: This study included patients with cervical radicular pain who underwent ultrasound-guided stellate ganglion block. Successful response was defined as a ≥4-point or ≥50% reduction in the numerical rating scale score at 3 months post-procedure compared with the pre-procedural baseline. Patients who did not meet these criteria or underwent additional interventional procedures for persistent cervical radicular pain within 3 months were classified as unsuccessful responders. Logistic regression analysis was performed to identify factors associated with treatment response. Results: Multivariable logistic regression analysis demonstrated that substantial cervical multifidus fatty degeneration, defined as Goutallier grade ≥2 of the cervical multifidus muscles (vs. minimal fatty degeneration, odds ratio (OR) 0.23, 95% confidence interval (CI): 0.08–0.66, p = 0.007) and bony hypertrophy at the uncovertebral or facet joint as the primary etiology of foraminal stenosis (vs. disc herniation, OR 0.35, 95% CI: 0.14–0.87, p = 0.024) were independently associated with lower odds of a successful response to stellate ganglion block. Steroid use was not significantly associated with treatment response (OR 0.52, 95% CI: 0.18–1.49, p = 0.223). The successful response rate declined progressively with the number of risk factors: 94.7% (18/19), 50.0% (22/44), and 40.7% (11/27) for zero, one, and two factors, respectively (p < 0.001). Conclusions: Substantial cervical multifidus fatty degeneration and foraminal stenosis attributable to bony hypertrophy may be associated with lower odds of a successful response to stellate ganglion block in patients with cervical radicular pain. These factors require prospective validation before routine clinical implementation.