The Impact of Local Corticosteroid Administration on the Incidence of Post-Neurotomy Neuritis: A Prospective Investigation.

BACKGROUND

Since its adoption as a treatment for neuropathic pain in the 1960s, radiofrequency ablation (RFA) has continued to gain popularity for the management of various pain etiologies. Although RFA is considered to be a safe procedure, post-neurotomy neuritis (PNN), a neuropathic-type pain, is one of the most common side effects. Due to the increasing recognition of PNN, some providers have attempted to mitigate the risk of PNN by injecting local corticosteroids at the site of RFA following the procedure. Recent studies have generally concluded that corticosteroids do not protect against the development of PNN, however, they have been limited by their retrospective study designs and the low incidence of PNN.

OBJECTIVES

We aimed to add to the growing literature regarding the role of post-RFA corticosteroid administration in preventing the development of PNN.

STUDY DESIGN

We conducted a prospective study evaluating the incidence of PNN as well as the efficacy of post-RFA corticosteroid administration in preventing the development of PNN.

SETTING

All RFAs were performed by the same board-certified, pain medicine fellowship-trained, attending physician at the University of Wisconsin who performed the initial patient evaluation at the pain medicine clinic.

METHODS

Thirty-nine patients (47 RFAs) were included in the study. All patients were between the ages of 30 and 81; 23 (59.0%) patients were women comprising 28 (59.6%) of the RFAs performed. RFA was performed for a variety of conditions, including facet joint pain, osteoarthritic knee pain, and occipital nerve pain. The 19 patients (25 RFAs) completed prior to February 2020 received post-RFA corticosteroids; the remaining 21 patients (22 RFAs) completed after this date did not receive corticosteroids. The Numeric Rating Scale (NRS-11) and Douleur Neuropathique 4 Questions (DN4) questionnaire scores were collected before and after completion of an RFA. After their procedure, patients were either called or seen in clinic for re-evaluation of their symptoms, at which time NRS-11 and DN4 scores were collected again.

RESULTS

There were no statistically significant differences between groups when comparing post-RFA DN4 scores. Additionally, the incidence of PNN in our study population was 0% for both treatment groups. The NRS-11 scores were similar between groups prior to completing an RFA. When comparing the post-RFA pain scores, the average NRS-11 scores in the steroid group decreased from 5.8 to 3.4, while the average NRS-11 scores in the nonsteroid group decreased from 5.4 to 3.8. However, the average NRS-11 reductions were similar between groups.

LIMITATIONS

The primary limitation of this study is small sample size, which likely limited our ability to diagnose PNN. Additionally, we utilized the 7-item DN4 and required a DN4 score of  ? 4 to diagnose PNN, and therefore, it is likely that our protocol significantly reduced our sensitivity for diagnosing PNN.

CONCLUSIONS

Overall, our study is in agreement with prior studies that RFA is effective for the treatment of facet and osteoarthritic knee pain and that the incidence of PNN is likely small.