Randomized placebo-controlled study evaluating lateral branch radiofrequency denervation for sacroiliac joint pain

Abstract

Background: Sacroiliac joint pain is a challenging condition accounting for approximately 20% of cases of chronic low back pain. Currently, there are no effective long-term treatment options for sacroiliac joint pain.

Methods: A randomized placebo-controlled study was conducted in 28 patients with injection-diagnosed sacroiliac joint pain. Fourteen patients received L4-L5 primary dorsal rami and S1-S3 lateral branch radiofrequency denervation using cooling-probe technology after a local anesthetic block, and 14 patients received the local anesthetic block followed by placebo denervation. Patients who did not respond to placebo injections crossed over and were treated with radiofrequency denervation using conventional technology.

Results: One, 3, and 6 months after the procedure, 11 (79%), 9 (64%), and 8 (57%) radiofrequency-treated patients experienced pain relief of 50% or greater and significant functional improvement. In contrast, only 2 patients (14%) in the placebo group experienced significant improvement at their 1-month follow-up, and none experienced benefit 3 months after the procedure. In the crossover group (n = 11), 7 (64%), 6 (55%), and 4 (36%) experienced improvement 1, 3, and 6 months after the procedure. One year after treatment, only 2 patients (14%) in the treatment group continued to demonstrate persistent pain relief.

Conclusions: These results provide preliminary evidence that L4 and L5 primary dorsal rami and S1-S3 lateral branch radiofrequency denervation may provide intermediate-term pain relief and functional benefit in selected patients with suspected sacroiliac joint pain. Larger studies are needed to confirm these results and to determine the optimal candidates and treatment parameters for this poorly understood disorder.

Trial registration: ClinicalTrials.gov NCT00373724.

Conflict of interest statement

Conflict of Interest: Steven Cohen lectured on sacroiliac joint pain at 2 symposiums sponsored by Baylis Medical: American Society of International Pain Physicians 9th Annual Meeting, June 25, 2007, Washington, DC; and International Spinal Interventional Society 15th Annual Meeting, July 20, 2007, Baltimore, Maryland. Disposable equipment (e.g. RF tubing and needles) supplied by Baylis Medical, Montreal, Quebec, Canada.

Figures

Figure 1

CONSORT chart showing progression of subjects in study arms. Footnotes: SIJ- sacroiliac joint, RF- radiofrequency, N- number of patients

Figure 2

Schematic diagram illustrating: A. Target points for right-sided conventional (L4 and L5) and cooled (S1–3) radiofrequency denervation at the junction of the L5 superior articular and transverse processes (L4 primary dorsal ramus), the sacral ala (L5 primary dorsal ramus), and S1-3 foramina (lateral branches). B. Anticipated lesions at each of the target points. Footnotes: L4 and L5- 4th and 5th lumbar spinal levels, respectively. S1–3- First, second and third sacral spinal levels, respectively.

Figure 3

Adjacent photographs demonstrating the difference in lesion size between cooled (A) and conventional (B) radiofrequency probes in chicken meat. Each small line represents a distance of 1 mm.

Figure 4

Bar graph demonstrating the percentage of patients with a successful treatment outcome at various time points. A positive outcome is defined as a ≥ 50% reduction in numerical pain score, a positive global perceived effect, and either a 10-point decrease in Oswestry disability index score or a 4-point decrease coupled with a reduction in medication usage. Footnote: TX- treatment