SI Joint Radiofrequency Ablation

Candidates have ongoing low back and buttock pain from the SI joint that has not improved with physical therapy and medication, and good relief from a diagnostic lateral branch block. The 2025 guideline recommends at least 50% relief from one block, though some societies prefer two blocks with at least 75% relief^[1]. People whose SI joint injections helped only briefly are often good candidates.

No — SI joint RFA is not a treatment for sciatica. Sciatica is leg pain from an irritated spinal nerve root, while SI joint RFA treats the small nerves that carry pain from the back of the sacroiliac joint^[1]. SI joint pain can spread to the buttock and thigh and be mistaken for sciatica, which is why a careful exam and a test block come first. True sciatica is usually treated with therapy or an epidural steroid injection.

Tell us about your medicines and any implanted device. The 2025 SI joint guideline found that blood thinners usually do not need to be stopped^[1], but only your doctors should decide — never stop a blood thinner on your own^[4]. A pacemaker or stimulator needs advance planning^[5]. Follow fasting instructions if sedation is planned, and arrange a ride home.

Most people describe it as uncomfortable rather than very painful. The skin is numbed, and each area is numbed again before heating, so you mainly feel pressure, warmth or aching while the probes are placed. You stay awake, sometimes with a light relaxing medicine^[11]. Because many nerves are treated, the procedure takes longer than a simple SI joint injection, and the area can be sore for a week or two.

Yes. You walk out the same day, and gentle walking is encouraged. Rest the first day, avoid driving and strenuous activity for 24 hours, and return to normal activities after a day or two^[11]. Expect soreness or a sunburn-like feeling over the buttock that can last up to two weeks; ice helps. Call us for fever, increasing pain or new leg weakness.

When it works, relief often lasts about six months to a year, but results vary. The 2025 guideline found strong evidence for at least six months of relief in well-selected patients^[1], and a cooled-RFA study reported an average of 7.9 months^[5]. In an earlier trial, only 14% of treated patients still had relief at one year^[8]. Some people get little benefit.

Yes, it can be repeated if the first treatment helped and the pain returns as the nerves regrow^[11]. Research on repeat SI joint RFA is limited, so your physician will confirm that the pain pattern is the same and may repeat a test block first. If relief is consistently short, other options such as SI joint fusion may be discussed.

The most common side effects are soreness and a temporary burning or sensitive feeling over the buttock^[11]. Nerve irritation (neuritis) can occur, and a patch of skin may feel numb^[1]. Infection, bleeding and injury to a nearby nerve root are uncommon^[11]. Trials have not reported serious adverse events, though they were too small to fully assess long-term safety^[2].

Medicare in New York does not: its sacroiliac joint policy states that SI joint denervation (RFA) is not considered reasonable and necessary, although it covers diagnostic and therapeutic SI joint injections within limits^[2]. Commercial plans vary: some cover it with prior authorization, and others do not. New York workers’ compensation back guidelines address facet RFA but not SI joint RFA^[3], and no-fault follows its own rules. We will check your benefits and discuss options before scheduling.

An SI joint injection places numbing medicine and usually a steroid into or around the joint, while RFA heats the nerves that carry pain from the back of the joint. Injections can confirm the diagnosis and give at least four weeks of relief in well-selected patients^[1]. RFA is designed to last longer — often six months or more — but requires a positive test block first^[1].

Besides RFA, newer options include minimally invasive SI joint fusion, which has weak evidence of benefit for at least a year in carefully selected patients with pain from inside the joint, and regenerative injections such as PRP or dextrose prolotherapy, which have weak evidence for at least three months of relief^[1]. Physical therapy, SI joint injections and a cluneal nerve block for nearby nerve pain are also options.

Larger lesions seem to help at the SI joint, but no single technique is proven best. Because the nerves are small and variable, guidelines found stronger evidence for larger or more aggressive lesioning strategies — such as cooled RFA or palisade lesions — than for less thorough techniques^[1]. Medicare’s review concluded there is not enough evidence to say that any one technique — monopolar, bipolar, cooled or palisade — is superior^[2].