BACKGROUND: Sacroiliac joint dysfunctional pain has always been an enigma to the pain physician, whether it be the diagnosis or the treatment. Diagnostic blocks are the gold standard way to diagnose this condition. Radiofrequency neurotomy of the nerves supplying the sacroiliac joint has shown equivocal results due to anatomical variation. Intraarticular depo-steroid injection is a traditional approach to treating sacroiliac joint pain. For long-term pain relief, however, lesioning the sacral lateral branches may be a better approach.
OBJECTIVE: This study compared the efficacy of intraarticular depo-methylprednisolone injection to that of pulsed radiofrequency ablation for sacroiliac joint pain.
STUDY DESIGN: This study used a randomized, prospective design.
SETTING: Thirty patients with diagnostic block-confirmed sacroiliac joint dysfunctional pain were randomly assigned to 2 groups. One group received intraarticular methylprednisolone and another group underwent pulsed radiofrequency of the L4 medial branch, the L5 dorsal rami, and the lateral sacral branches.
RESULTS: Reduction in Numeric Rating Scale (NRS) for pain at 1 month post-procedure remained similar in Group A, while in Group B few patients reported a further decrease in the NRS score (3.333 ± 0.4880 and 2.933 ± 0.5936, respectively). At 3 months post-procedure, the NRS score began to rise in most patients in group A, while in Group B, the NRS score remained the same since the last visit (4.400 ± 0.9856 and 3.067 ± 0.8837, respectively). At 6 months post-procedure, the NRS score began to rise further in most patients in group A. In Group B, the NRS score remained the same in most of the patients since the last visit (5.400 ± 1.549 and 3.200 ± 1.207). There was a marked difference between the 2 groups in Oswestry Disability Index (ODI) scores at 3 months post-procedure (Group A, 12.133 ± 4.486 vs Group B, 9.133 ± 3.523) and at 6 months post-procedure there was a significant (P = 0.0017) difference in ODI scores between Group A and Group B (13.067 ± 4.284 and 8.000 ± 3.703, respectively). Global Perceived Effect (GPE) was assessed in both groups at 3 months post-procedure Only 33.3% (Confidence Interval (CI) of 11.8- 61.6 ) of patients in Group A had positive GPE responses whereas in Group B, 86.67% (CI of 59.5- 98.3 ) of patients had positive GPE responses. At 6 months post-procedure, the proportion of patients with positive GPE declined further in Group A, while in Group B, positive GPE responses remained the same (20% with a CI of 4.30- 48.10 and 86.67% with a CI of 59.5- 98.3, respectively ).
LIMITATIONS: Small sample size.
CONCLUSION: This comparative study shows that pulsed radiofrequency denervation of the L4 and L5 primary dorsal rami and S1-3 lateral branches provide significant pain relief and functional improvement in patients with sacroiliac joint pain.
KEY WORDS: Low back pain, sacroiliac joint dysfunctional pain, radiofrequency, intraarticular injection.
As a rheumatologist, a 2.2 point difference at 6 months in NRS pain score (5 vs 3) seems of little clinical significance, especially considering that no difference was observed at 3 months. Long-term follow-up looking at adverse events would be of interest.