Intradiscal electrothermal therapy for symptomatic internal disc disruption: 24-month results and predictors of clinical success

Abstract

Degeneration of the intervertebral disc can be the source of severe low-back pain. Intradiscal electrothermal therapy (IDET) is a minimally invasive treatment option for patients with symptomatic internal disc disruption unresponsive to conservative medical care. This study was undertaken in the neurosurgical setting to evaluate 24-month pain and functional outcomes and predictors of clinical success in patients with discogenic back pain treated with IDET. Using MR imaging and discography findings, 50 patients with lumbar discogenic pain were identified, underwent IDET treatment, and were followed up for 24 months. Outcomes included assessments of back pain severity based on an 11-point numeric scale and back function based on the Oswestry Disability Index. The Prolo scale was applied to determine economic and functional status at 24 months. There was an average 68 and 66% improvement in back pain and function, respectively, between pretreatment and 24 months after treatment (p < 0.0001 for both comparisons). A maximum score of 5 on the Prolo scale for economic and functional status was achieved in 63 and 22% of patients, respectively. The global clinical success rate was 78% (39 of 50 patients) based on no reoperations at the affected level due to persistent symptoms, with a >or= 2-point improvement in pain severity and a >or= 15-point improvement in back function. Predictors of 24-month clinical success included discographic concordance (p < 0.0001), a high-intensity zone on MR imaging (p = 0.0003), low Pfirrmann grade (p = 0.0002), and more extensive anulus coverage (p < 0.0001). There were no procedure-related adverse events. The findings of this study suggest that durable clinical improvements can be realized after IDET in highly select surgical candidates with mild disc degeneration, confirmatory imaging evidence of anular disruption, and highly concordant pain provocation on low-pressure discography.