Minimally-invasive percutaneous treatments for low back pain and leg pain: a randomized controlled study of thermal disc decompression versus mechanical percutaneous disc decompression.

Background Context: Minimally invasive techniques have recently been developed as alternative treatments to surgical interventions, especially for small or contained herniated disc.

Purpose: Aim of our study is to assess the efficacy of the mechanical percutaneous disc decompression (PDD) in comparison with the percutaneous radiofrequency targeted disc decompression (TDD).

Study Design: We conducted a single-center noninferiority trial in which patients who had low back pain with radicular leg pain (RLP) from a contained herniated disc were randomly assigned in a 1:1 ratio to undergo either PDD or TDD.

Patient Sample: From January 2016 to January 2017 a total of 327 patients were assessed for eligibility of whom 200 underwent randomization in the trial; 100 patients underwent the PDD and 100 underwent the TDD.

Outcome Measures: The primary outcome measure was the proportion of patients who reported >50% reduction in Numeric Rating Scale (NRS) leg pain score. Secondary outcome measure included the proportion of patients who reported >30% improvement in Oswestry Disability Index (ODI) score.

Methods: Outcomes of this trial were measured with the use of patient-reported data obtained from validated questionnaires to assess the low back pain with RLP before intervention and at 6 and 12 months after interventions. MRI was performed before intervention and at 6 and 12 months after interventions. In addition to NRS and ODI scores, we collected the following data: age, gender, length of hospitalizations and return to work rate.

Results: When using an intention to treat analysis with those lost to follow-up and requiring a second procedure counting as failures, there were no statistically significant difference between the two treatment groups in the primary and secondary outcomes at 6 months: >50% reduction in NRS leg pain (PDD vs. TDD)=67% versus 65%; >30% ODI improvement (PDD vs. TDD)=57% versus 55%. Similarly, there were no statistically significant differences between groups in outcomes at 12 months: >50% reduction in NRS leg pain (PDD vs. TDD)=51% (95% CI 41%-60%) versus 40% (95% CI: 30%-49%); >30% ODI improvement (PDD vs. TDD)=42% (95% CI 32%-51%) versus 30% (95% CI: 21%-39%). A nonintention to treat analysis which discounted those lost to follow-up showed the only statistically significant finding was the percentage of those reporting >30% ODI at the 12 month follow-up time, favoring the PDD group: (PDD vs. TDD)=58% (95% CI 46%-69%) versus 42% (95% CI: 22%-43%).

Conclusions: PDD and TDD are comparable treatments for patients presenting with low back pain with RLP unresponsive to medical therapy caused by contained disc herniations.