Patient Preparation and Diagnostic Blocks
Appropriate patient selection is critical for the success of sacroiliac joint radiofrequency ablation. Candidates include patients with chronic sacroiliac pain refractory to conservative therapies, confirmed by diagnostic blocks.
Standard protocols recommend fluoroscopy-guided posterior sacral network (PSN) blocks or intra-articular injections, with ≥50% pain relief required to qualify as positive. Two confirmatory blocks are advised to minimize false positives.
Preparation includes a full medical history, review of anticoagulant or antiplatelet therapy, and optimization of comorbid conditions.
Patient education is essential, ensuring realistic expectations, clear understanding of risks, and informed consent.
Electrode Placement Under Imaging Guidance
The procedure is performed with the patient in prone position under fluoroscopic guidance. Biplanar imaging (AP and lateral) ensures accurate anatomical targeting.
Nimbus Stratus multitined electrodes allow for continuous lesion creation along the lateral sacral crest, specifically adjacent to the posterior sacral foramina from S1 to S3.
Electrodes should be advanced to follow the course of the PSN, with slight angulation to optimize coverage. Sensory and motor stimulation testing at low intensity confirms proximity to the target nerves.
Accurate placement reduces technical failures and maximizes clinical outcomes.
RF Parameters and Lesion Creation
Recommended Nimbus Stratus parameters are 85°C for 180 seconds for multitined lesions, with optional supplemental monopolar points at 80°C for 90 seconds.
These extended lesions account for anatomical variability and enhance the likelihood of nerve capture.
The generator monitors thermal stability to maintain consistent lesion formation throughout the duration.
Clinical and anatomical studies confirm a correlation between lesion size and higher rates of treatment success.
Intraoperative Safety Monitoring
Continuous monitoring of ECG, blood pressure, oxygen saturation, and respiratory rate is mandatory during the procedure.
Conscious sedation is preferred, maintaining patient responsiveness for stimulation testing.
Strict aseptic technique reduces infection risk, while the availability of resuscitation equipment and trained personnel ensures rapid management of complications.
The multitined design reduces the number of punctures required, improving procedural safety.
Post-Procedure Care and Follow-Up
Following the procedure, patients should be observed for 1–2 hours before discharge. Localized soreness is common and manageable with mild analgesics.
Most patients resume daily activities within 24–48 hours. Extended monitoring may be indicated for frail or comorbid patients.
Follow-up assessments at 1, 3, 6, and 12 months using NPRS, ODI, and EQ-5D scales are recommended to document outcomes.
Repeatability of Nimbus Stratus procedures provides long-term sustainability in pain management.
Best Practices for High Success Rates
Centers of excellence should standardize protocols to ensure reproducibility across operators.
Ongoing physician training and integration of Stratus into multidisciplinary care pathways are key to optimizing patient outcomes.
Regular clinical audits and data collection in registries enhance quality assurance and contribute to evidence-based guideline updates.
These best practices ensure safe, effective, and consistent use of Nimbus Stratus in interventional pain management.
References
- Al-Kaisy A., Pang D., Desai M., McNamee D. NIMBUS: A Novel Multi-Tined Expandable Electrode for Percutaneous Radiofrequency Lesioning of the Sacroiliac Joint. Orthopaedic Proceedings, 2018.
- Conger A., Kendall R., McCormick Z., Wagner G., Burnham T. Double-Blind Randomized Trial of Radiofrequency Ablation for Sacroiliac Joint Pain. University of Utah, 2022.
