Background: Lumbar spondylosis with associated facet joint degeneration is a common cause of lower back pain. This causes debilitating lower back pain and referred dermatomal lower limb pain. Standard conservative treatment with analgesics, and a physiotherapy rehabilitation programme can resolve this condition in many patients. For persistently symptomatic patients, various interventional treatment modalities have been developed with different degrees of success. Common 1st line intervention treatment would be facet joint steroid injections, nerve blocks for pain relief. For severe pain symptoms, medial branch nerve-facet joint radiofrequency ablation(RFA) has shown good medium-term results. The common sized needles used include 20G diameter needles with a 10mm length active lesioning tip.

There are different types of the RF needles and probe systems. The interventional techniques have also been controversial. Variability in lumbar vertebral bone anatomy, medial branch nerve course is also an issue. This can result in inaccurate targeting, and the variable clinical results. Different needles and probes developed include the basic straight needle cannula-probe, multi-tined probes, cooled RF probes, and angled Sidekick 2 type cannula-probes®, with a separate lumen for the probe to emerge. These newer probes aim to generate a larger RF lesion size. This would include more of the medial branch nerve in the lesion for better long-term pain relief.

Objectives: The purpose of our study is to compare the clinical results of the above devices, and also present our personal experience with 2 different RF devices (‘Sidekick’ type needles vs straight needles, both similar in length, diameter), but with the ‘Sidekick’ generating a larger lesion.

Methods: In our study, we searched PubMed and Medline for relevant studies on lumbar facet joint radiofrequency ablation. We also reviewed the author’s personal prospective series on facet joint-medial branch nerve radiofrequency ablation (RFA) from 2024 to 2026. The primary outcome measures for success were improvement in Visual Analogue Scores (VAS) by 50% at 3 months and at 6 months post-procedure. Other outcome measure indices included the Owestri Disability Index (ODI), and the incidence of neurological lower limb side effects/complications.

Study Results and Discussion: RF devices such as the conventional straight needle needle-probe, multi-tined probes, cooled RF devices were studied. Promising improvements in pain VAS scores range from 51.7% to 55% using these devices. Some aim to generate a larger diameter spherical RF lesion. Another more recent lesioning technique involves inserting 2 needles, placed on either side to encompass the medial branch nerve for a larger lesion volume.

From our personal prospective series of 44 patients, comparing the standard straight 20G RF needle, vs the ‘Sidekick 2’ probe, our results showed good improvements in VAS scores. In the first group of patients which were treated with the standard 20G needle, there were 22 patients, treated from January 2024 onwards. The average age of the patients was 55 years. There were 8 female and 14 male patients. The second group was treated with the newer 20G, angled needle tip needle(Boston® ‘Sidekick 2’). There were 22 patients, treated from September 2025 onwards. Eleven were male and 11 were female patients. The average age of patients was 54 years. The results of the VAS pain scores were assessed at 3 and 6 months post-procedure. A successful outcome was a reduction in the VAS pain score by 50%. In the ‘Sidekick’ group, there was improved results, 75% improved versus 65% in the standard straight RF needle group. The difference was statistically significant(p<0.05). In both the 2 groups, there was 1 case(4.5%) of transient leg numbness with dermatomal pain. This improved after 1 month of treatment with medication. There were no incidence of neurological defects in both groups. No patients subsequently needed lumbar spine surgery such as fusion.

Conclusion: In conclusion, lumbar facet joint RFA has an important role in the treating lower back pain. Various RF needles and probes have been developed to increase the lesion size with a view to improve efficacy. The newer ‘Side-kick’(Boston Scientific®) device shows promising results and can be considered in selected patients. Patients with a high BMI, variable lumbar facet anatomy, and those with recurrence facet joint syndrome pain can benefit from this device.