Clinical evaluation of ultrasound-guided facet joint injection in patients with low back pain: a comparison with fluoroscopy

Abstract

Introduction: Facet syndrome is a common cause of chronic low back pain in adults and can lead to significant functional limitations. Facet injections are part of the interventional management of these patients and are typically performed under fluoroscopy or CT guidance. Although these techniques allow for adequate anatomical localization, they involve exposure to ionizing radiation. Ultrasound offers real-time guidance, wide availability, and is radiation-free, making it a potentially useful alternative for these procedures.

Objective: To evaluate the clinical efficacy of ultrasound-guided facet joint injections in patients with low back pain secondary to facet syndrome, using the SF-36 MCS, SF-36 PCS, Roland-Morris, Oswestry, and Visual Analog Scale pre-intervention and at three months. Additionally, to compare these results with those obtained using fluoroscopy and to identify complications or adverse events.

Methodology: A comparative study in patients with chronic low back pain undergoing ultrasound-guided or fluoroscopy-guided facet injections. A descriptive analysis of demographic and clinical variables was performed. Normality was assessed using the Kolmogorov-Smirnov test. Quantitative variables were compared using Student’s t-test for independent samples; qualitative variables were analyzed using the chi-square test. Statistical significance was considered at p < 0.05.

Results: A total of 42 patients with a mean age of 47.88 ± 14.68 years were analyzed; 59.5% (25/42) were women and 40.5% (17/42) were men. The mean BMI was 26.76±3.46 kg/m². The diagnoses were degenerative disc disease in 45.2% (19/42), facet syndrome in 33.3% (14/42), and lumbar spinal stenosis in 21.4% (9/42). 57.1% (24/42) underwent injection under fluoroscopy and 42.9% (18/42) under ultrasound guidance. At baseline, the scores were: Oswestry 48.31 ± 14.28%, Roland-Morris 14.53 ± 4.49 points, SF-36 PCS 35.91 ± 21. 16%, SF-36 MCS 55.97±15.80%, lumbar VAS 6.94±1.26 points, and radicular VAS 4.75±1.88 points. At three months, a statistically significant improvement was observed on all assessed scales (p<0.05), Table 1.

In addition, the means were compared according to the intervention method, Table 2. In the ultrasound group, a skin rash accompanied by vomiting was reported in one case, representing 2.4% (1/42); this was considered a complication resulting from the medication used and was not statistically significant. The frequency of surgeries at the end of follow-up was 7.1% (3/42); these patients required surgical management due to persistent symptoms, all of whom underwent fluoroscopy-guided injections, which was not statistically significant.

Conclusion: Ultrasound-guided facet injections resulted in significant clinical improvement at three months in terms of pain, disability, and quality of life, with results comparable to those obtained using fluoroscopy. These findings suggest that ultrasound may be an effective and safe alternative for guiding facet injections in patients with chronic low back pain, with the advantage of avoiding exposure to ionizing radiation and facilitating access to the procedure. Although no significant differences were observed between the two methods, prospective studies with larger sample sizes are needed to confirm these results and more precisely define their clinical indications.