What Is a Rhizotomy Procedure and How Does It Work?

A rhizotomy is a procedure that deliberately damages or destroys a nerve root, or a branch of one, to block it from transmitting pain signals. The term comes from the Greek words for “root” and “cut,” and rhizotomies have been performed in various forms since the 1880s. In practice, most rhizotomies today use heat from a radiofrequency needle to disable small sensory nerves, though some involve surgical cutting, freezing, or chemical destruction depending on the condition being treated. The procedure spans a surprisingly wide range of medical problems, from chronic back pain to facial nerve disorders to childhood spasticity, and the technique used varies dramatically between them.

How Radiofrequency Rhizotomy Works

The most common form of rhizotomy in pain medicine is radiofrequency ablation, sometimes called radiofrequency neurotomy. The basic idea is straightforward: a thin needle-like electrode is guided to the nerve responsible for transmitting pain, and radiofrequency energy heats the tip to a temperature high enough to destroy the nerve tissue. Conventional thermal radiofrequency reaches temperatures between 70 and 90°C at the nerve target, which is enough to create a small, controlled burn that disables the nerve’s ability to send signals.¹ The procedure is typically done under fluoroscopic or CT guidance so the physician can see exactly where the needle tip sits relative to the target nerve and surrounding structures.

You are awake for this, usually with light sedation and local anesthesia at the skin entry point. The whole thing takes roughly 30 to 90 minutes depending on how many nerves are being treated. Before the ablation itself, the physician often runs a brief electrical stimulation test through the needle to confirm it is in the right spot. Sensory stimulation should reproduce a familiar buzzing or tingling in the area of your usual pain, while motor stimulation checks that no nearby motor nerve is at risk of being damaged. Once placement is confirmed, the radiofrequency current is applied for a set duration, and the nerve is lesioned.

Getting Diagnosed First

A rhizotomy is not the first step in treating chronic pain. Before anyone puts a radiofrequency needle near your spine, the clinical standard is to perform at least one diagnostic nerve block. The logic is simple: if temporarily numbing a specific nerve with a local anesthetic makes your pain go away, that nerve is likely the pain source, and permanently disrupting it should provide longer-term relief. A positive response to what is called a medial branch block is accepted as confirmation that the facet joint those nerves supply is the source of the pain, and it serves as a predictor of how well radiofrequency ablation will work.²

There is genuine debate in the field about whether you need one diagnostic block or two before proceeding. Requiring two blocks (done on separate visits) reduces false positives, since some people report temporary relief from a block just due to placebo or the natural fluctuation of their symptoms. But double blocks also mean more visits, more cost, and more time waiting in pain. Different guidelines and insurance policies land on different sides of this question, and in practice, many interventional pain physicians use a single block with a high pain-relief threshold as sufficient evidence to move forward.

Lumbar Facet Joint Pain

The single most common reason people get a radiofrequency rhizotomy is chronic pain from the lumbar facet joints, the small paired joints that run along the back of the spine. These joints can become painful from arthritis, injury, or simply long-term wear, and because the pain is often a deep, diffuse ache in the lower back that worsens with twisting or extension, it overlaps with many other causes of back pain. The diagnostic block described above is the key to identifying facet joints as the culprit.

Once confirmed, radiofrequency ablation of the medial branch nerves that supply those joints has consistently outperformed steroid injections for longer-term relief. In a comparative trial, both radiofrequency ablation and steroid injections improved pain and function in the short term, but the radiofrequency group maintained significantly greater pain reduction and functional improvement at three and six months.³ A randomized trial of cooled radiofrequency ablation versus facet joint steroid injection found an even starker difference: about 70% of the ablation group met the threshold for a meaningful pain response at three months, compared to 25% in the steroid group.⁴ By 12 months, the gap had narrowed but ablation still maintained a clear advantage.

A multicenter trial comparing radiofrequency ablation, cryoablation, and endoscopic denervation for lumbar facet pain found that all three approaches provided significant and sustained improvement over two years of follow-up, with radiofrequency ablation delivering the most consistent long-term results.⁵

Trigeminal Neuralgia

Rhizotomy also has a long history in treating trigeminal neuralgia, a condition involving sudden, severe, shock-like facial pain along one or more branches of the trigeminal nerve. When medications like carbamazepine stop controlling the pain, percutaneous rhizotomy is one of the standard procedural options. A needle is passed through the cheek into the skull base, targeting the trigeminal nerve root at a structure called the Meckel’s cave, and radiofrequency energy is applied to selectively damage the pain-transmitting fibers.

In a prospective study, about 80% of trigeminal neuralgia patients treated with radiofrequency rhizotomy achieved excellent or good pain relief through six months.⁶ The tradeoff is that pain recurrence over time is common. A comparison study found that radiofrequency rhizotomy for trigeminal neuralgia had a 40% recurrence rate, and the median time to recurrence was considerably shorter than with microvascular decompression, a more invasive open surgery that addresses the underlying cause of the nerve compression rather than simply destroying nerve fibers.⁷

Microvascular decompression remains the gold standard when a patient is healthy enough for open surgery. A long-term comparison found that about 87% of microvascular decompression patients achieved excellent initial pain relief versus roughly 67% for percutaneous procedures, and the durability was also superior: 25% of microvascular decompression patients had recurrence at about eight years, compared to roughly one year for percutaneous techniques.⁸ Percutaneous rhizotomy therefore tends to be favored for older patients or those with significant medical conditions that make open surgery risky.

Selective Dorsal Rhizotomy for Spasticity

Selective dorsal rhizotomy, or SDR, is an entirely different animal from the radiofrequency procedures described above. It is a neurosurgical operation performed primarily in children with cerebral palsy who have spasticity, meaning their muscles are abnormally stiff and resistant to movement. The surgeon exposes the spinal nerve roots in the lower back through a laminectomy, then uses electrical stimulation to test individual nerve rootlets. Rootlets that produce abnormal reflex responses are selectively cut, reducing the overactive nerve signaling that drives the spasticity while preserving as much normal sensation and motor function as possible.⁹

A systematic review and meta-analysis found that SDR significantly improved both spasticity scores and gross motor function in children with lower-limb spasticity, with the treatment effects remaining significant up to 12 months after surgery.¹⁰ Unlike radiofrequency rhizotomy, SDR is a permanent procedure. The cut nerve rootlets do not regenerate in a clinically meaningful way, so the reduction in spasticity tends to be lasting. This is both its greatest benefit and the reason patient selection is critical: you cannot undo it if the results are not what you hoped for.

Intensive postoperative physical therapy is considered essential for a good SDR outcome. The surgery reduces the spasticity, but the child’s muscles, joints, and movement patterns have developed around that spasticity for years. Without sustained rehabilitation to build strength, flexibility, and new motor patterns, the functional gains from reducing tone can be limited.¹¹ A worldwide survey of SDR centers found that while the surgery itself is fairly standardized, the rehabilitation protocols that follow it vary widely in duration, frequency, and modalities used.¹²

Why the Pain Comes Back

For radiofrequency rhizotomy, the most common frustration is that pain relief is temporary. After a conventional thermal ablation, the nerve is damaged severely enough to stop conducting pain signals, but the nerve sheath and surrounding structural framework are left intact. This means the nerve can regenerate along its original path over a period of months. Pain typically returns somewhere between six and 18 months after the procedure, depending on the individual and the specific nerve treated.

This is a feature of the injury type, not a failure of the technique. The damage produced by radiofrequency ablation is designed to be reversible at the nerve level, which is what makes it relatively safe but also what necessitates repeat procedures.¹³ The molecular machinery that drives nerve regrowth involves signaling between the damaged nerve fibers and the glial cells that surround them, along with growth factors and structural molecules that guide the regenerating axon back along its original track. For patients who respond well to their first ablation, the procedure can generally be repeated with similar effectiveness.

Risks and Complications

Radiofrequency rhizotomy for back pain is considered a low-risk procedure. The most common side effects are temporary soreness or burning at the treatment site for a few days to a couple of weeks. Infection, bleeding, and nerve damage beyond the intended target are possible but uncommon with modern imaging guidance. Some people experience a temporary increase in pain before things improve, which can be unsettling but usually resolves within a few weeks.

The more serious complication specific to rhizotomy procedures is the development of new, unwanted pain in the area that has been denervated. After destruction of trigeminal nerve rootlets, a small but meaningful percentage of patients develop persistent unpleasant sensations, called dysesthesias, in the area that has lost normal sensation. This has been reported in roughly 5 to 15% of patients after trigeminal rhizotomy.¹⁴ Spinal posterior rhizotomy produces a different pattern of post-procedure pain in fewer than 4% of cases, often characterized by allodynia, where normally painless touch becomes painful, and paradoxically the pain may be felt beyond or even on the opposite side of the treated area.

For percutaneous radiofrequency procedures near the spinal cord, there are rare but serious risks in patients with pre-existing cardiovascular disease. Case reports have documented contralateral weakness after spinal rhizotomy in elderly patients with cardiac failure and generalized vascular disease, likely due to heat-induced disruption of blood flow to the spinal cord itself. This highlights why patient selection matters and why physicians screen for cardiovascular risk factors before proceeding.

Variations on the Technique

Radiofrequency rhizotomy is not a single monolithic procedure. Several variations exist, each with different properties that suit different clinical situations.

Pulsed radiofrequency: Instead of continuous heat, pulsed radiofrequency delivers brief bursts of energy with pauses in between, keeping the tissue temperature around 42°C rather than the 70–90°C of conventional ablation.¹⁵ The analgesic effect comes from electromagnetic field exposure rather than tissue destruction, making it a neuromodulation technique rather than a neurolytic one.¹ The appeal is that it avoids nerve damage, but for lumbar facet pain, conventional ablation tends to produce better and longer-lasting results.
Cooled radiofrequency: This uses an internally cooled electrode that allows the surrounding tissue to reach ablation temperature over a larger area without charring at the needle tip. The result is a bigger lesion, which may improve the odds of fully capturing the target nerve, especially for anatomically variable structures like the sacroiliac joint.
Endoscopic rhizotomy: The nerve is visualized directly through a small endoscope and cut or ablated under direct vision rather than relying on fluoroscopic shadows. A real-world comparison found that endoscopic rhizotomy for lumbar facet pain produced longer pain-free survival than conventional radiofrequency, with a median pain-free duration of 20 months versus 10 months.¹⁶ Endoscopic approaches for cervical facet pain also exist, allowing precise neurotomy of the medial branch under advanced visualization.¹⁷
Cryoneurolysis: Instead of heat, extreme cold is applied to the nerve. The goal is the same disruption of pain conduction, but the cold injury tends to produce a cleaner separation of the nerve fibers from their insulating sheath, with evidence suggesting a low risk profile and prolonged pain relief without motor nerve damage.¹⁸
Chemical rhizotomy: Agents like phenol or alcohol are injected around the nerve root to chemically destroy it. This approach has been used in the management of cancer pain, particularly perineal pain from pelvic malignancies, where subarachnoid phenol injection has been described as one of the more effective options for pain control.¹⁹

How Rhizotomy Evolved

The history of rhizotomy is a story of progressive refinement toward smaller injuries and more precise targeting. The first posterior rhizotomy for pain was performed by Abbe in the 1880s, and early practitioners like Foerster applied the concept to spasticity in the early 1900s by dividing entire dorsal nerve roots from T12 to S2.²⁰ The results were often dramatic but so were the side effects, because cutting everything meant sacrificing useful sensation along with the harmful spasticity.

For pain management, modern radiofrequency rhizotomy traces its lineage to the 1960s, when Rees developed a technique he called “percutaneous rhizolysis” using a scalpel blade inserted through the skin. In 1971, Shealy introduced radiofrequency electrodes for facet joint denervation, and collaborations with medical device engineers through the 1970s produced the first purpose-built rhizotomy electrode kits. Bogduk’s anatomical work in 1980 refined the technique into what is now called percutaneous lumbar medial branch neurotomy, placing it on a firmer anatomical and evidence foundation. Pulsed radiofrequency arrived in 1998, followed by cooled radiofrequency, multi-tined cannulae, and endoscopic systems.²¹

For SDR, the parallel evolution involved surgeons progressively limiting how much nerve tissue they cut. Gros refined Foerster’s total root division by sectioning only four-fifths of each dorsal root. Warwick Peacock in Cape Town is credited with the modern revival of SDR, using a longer surgical exposure that allowed individual rootlets to be tested and selectively divided. More recent techniques have pushed toward even smaller bone windows, such as the keyhole interlaminar approach developed by Sindou, which reduces the amount of spinal ligament and bone removed during surgery.²⁰

Effects on Opioid Use

One of the more interesting downstream effects of radiofrequency rhizotomy is its potential impact on opioid consumption. A retrospective evaluation of patients who received cooled radiofrequency denervation for sacroiliac joint pain found that opioid doses dropped significantly at each follow-up point over a year. At the six-month mark, about 41% of patients had stopped taking opioids entirely. Even patients whose pain procedure was classified as unsuccessful by pain score criteria showed similar reductions in opioid use, suggesting the procedure may contribute to breaking the cycle of opioid dependence even when pain relief is incomplete.²²

A cost-effectiveness analysis comparing radiofrequency neurotomy to pain rehabilitation programs for facet joint pain found that both approaches had similar overall medication consumption patterns at one year, with neither dramatically changing total medication use. Pain-specific medication use shifted slightly in both groups, but the differences were small.²³ The opioid reduction story, in other words, may depend heavily on which joint is treated and which patient population is studied. The sacroiliac joint data is encouraging but should not be taken as a universal guarantee that rhizotomy will get you off pain medication.

1
PubMed Central. A comparison of pulsed radiofrequency and radiofrequency denervation for lumbar facet joint pain
2
ASRA Pain Medicine News. Evidence for Diagnostic Blocks Prior to Radiofrequency Ablation of Innervation to the Lumbar Facet Joints—None, Once, or Twice?
3
PubMed. A Comparative Study of Radiofrequency Ablation and Steroid Injection Therapy for Lumbar Facet Joint Pain: Clinical Efficacy and Outcomes
4
PubMed Central. A pragmatic randomized prospective trial of cooled radiofrequency ablation of the medial branch nerves versus facet joint injection of corticosteroid for the treatment of lumbar facet syndrome: 12 month outcomes
5
PubMed Central. Comparative Effectiveness of Radiofrequency Ablation, Cryoablation, and Endoscopic Denervation for Lumbar Facet Pain: A Multicenter Trial
6
PubMed Central. Percutaneous Radiofrequency Rhizotomy in Treatment of Trigeminal neuralgia: A Prospective Study
7
PubMed Central. A refined percutaneous rhizotomy with DSA-guided ethanol for the second-line treatment of trigeminal neuralgia
8
PubMed Central. Comparison of first-time microvascular decompression with percutaneous surgery for trigeminal neuralgia: long-term outcomes and prognostic factors
9
PubMed Central. Single-level selective dorsal rhizotomy for spastic cerebral palsy
10
PubMed. Efficacy of selective dorsal rhizotomy in the treatment of spasticity in children with cerebral palsy: a systematic review and meta-analysis
11
Pediatric Neurology. Selective Dorsal Rhizotomy: Patient Demographics and Postoperative Physical Therapy
12
PubMed Central. Selective dorsal rhizotomy from indication to rehabilitation: a worldwide survey
13
PubMed Central. Neural Ablation and Regeneration in Pain Practice
14
PubMed. Deafferentation pain after posterior rhizotomy, trauma to a limb, and herpes zoster
15
PubMed. Effectiveness and safety of pulsed versus thermal radiofrequency in the treatment of Morton’s disease
16
PubMed. Pain-Free Survival After Endoscopic Rhizotomy Versus Radiofrequency for Lumbar Facet Joint Pain: A Real-World Comparison Study
17
Interventional Pain Surgery. Full-Endoscopic Cervical Medial Branch Neurotomy
18
PubMed Central. The applications of cryoneurolysis for acute and chronic pain management
19
Minerva Anestesiologica. Chemical rhizotomy using phenol in the treatment of perineal pain of neoplastic origin
20
Neurotherapeutics. The Evolution of Selective Dorsal Rhizotomy for the Management of Spasticity
21
PubMed Central. A History of the Development of Radiofrequency Neurotomy
22
PubMed Central. Reduction of opioid intake after cooled radiofrequency denervation for sacroiliac joint pain: a retrospective evaluation up to 1 year
23
Interventional Pain Medicine. Cost-effectiveness of radiofrequency neurotomy to treat zygapophysial joint pain compared with pain rehabilitation programs