Background: Radiofrequency neurotomy (RFN) is a therapy aimed at providing lasting back pain relief for sacroiliac joint (SIJ) pain. A recent advancement in RFN is a strip lesioning technique that involves placement of a single curved electrode and a 3-pole design that facilitates the creation of 5 overlapping lesions. These lesions form one long strip lesion accessible through a single entry point, without the need for multiple punctures. Although the early case series data looks promising, there is lack of long-term, randomized, controlled study evaluating the strip-lesioning system for SIJ pain.
Objectives: The purpose of this study was to examine the safety and effectiveness of RFN using a strip lesioning device for reduction of SIJ pain.
Study design: Prospective, double-blind, randomized, sham-controlled trial with 6-month follow-upSETTING: A tertiary care interventional pain management center in the UK METHODS: Patients with SIJ pain with positive diagnostic local anesthetic blocks were randomly assigned (2:1) to either the sham (no RF lesions performed) or the active group (RF lesions performed). The primary endpoint was improvement of pain using the Numeric Rating Scale (NRS-11) at 3 months. Results were analyzed using nonparametric tests. Safety, secondary, and long-term outcome data were also collected.
Results: Seventeen of 30 enrolled patients were randomly assigned to active treatment (n = 11) or sham treatment (n = 6). At 3 months, the mean NRS-11 score for the active group had decreased significantly, from 8.1 (± 0.8) at baseline to 3.4 (± 2.0) (P < 0.001). The sham group did not experience a statistically or clinically meaningful decrease in mean NRS-11 score from baseline (7.3 ± 0.8) to 3 months (7.0 ± 1.7). On average, patients in the active group moved from borderline anxiety at baseline (9.4 ± 5.9) to no anxiety (6.6 ± 6.3) at 3 months. Results were similar at 6 months.
Limitations: Recruitment was stopped at 30 enrolled patients, only 17 of whom were randomly assigned to active or sham treatment, after the interim analysis indicated a statistically significant (P < 0.001) difference in the pain outcome between the treatment and the sham groups.
Conclusions: This study demonstrated that radiofrequency neurotomy using a strip lesioning device is an appropriate therapy to treat SIJ pain.
Key words: Radiofrequency, sacroiliac joint pain, low back pain, neurotomy, randomized controlled trial, simplicity.
Trial registration: ClinicalTrials.gov NCT01726608.