Minimally Invasive & Decompression

The mild® Procedure for Spinal Stenosis: What Naples Patients Need to Know

By Dr. Mark Frenkel, MD, MA, FAANS, FCNS  |  Board-Certified Neurosurgeon & Spine Surgeon, Naples, Florida

Patients often walk into my office holding a printed ad or a TV clip. “Doctor, can I just have the mild procedure? No implants, no stitches, home the same day.” I understand the appeal. When your legs give out after a few hundred feet, anything that sounds easier than surgery deserves a hard look.

Here’s my honest take. The mild® procedure is a legitimate, evidence-backed option for one specific kind of lumbar spinal stenosis. It is not a universal fix, and it is not right for many patients who are told it is. The difference comes down to exactly what is pinching your nerves.

In this article, I’ll explain how the mild procedure works, who is a genuine candidate, what the clinical trials actually show (and what they don’t), how it compares with surgical decompression, and the questions I’d ask before agreeing to it.

What Is the mild Procedure, Exactly?

The name stands for minimally invasive lumbar decompression. It is a percutaneous, image-guided procedure designed to relieve pressure on the nerves in the lower back without an open incision or any implant. The technology was developed by Vertos Medical, which Stryker acquired in 2024.

To understand it, you need to know one piece of anatomy. Running along the back of your spinal canal is a band of tissue called the ligamentum flavum. With age, it thickens and buckles inward, narrowing the canal and crowding the nerves. In many patients, that thickened ligament is a major contributor to their stenosis.

How the procedure works

1. You lie face down, usually under local anesthetic with light sedation.
2. Using live X-ray (fluoroscopy) and contrast dye to outline the spinal canal, the physician places a small access portal through a tiny skin opening.
3. Specialized tools remove small pieces of the thickened ligament and a sliver of bone to open the canal behind the nerves.
4. The portal is removed. The opening is typically closed with an adhesive strip rather than stitches.

Nothing is left behind in your body. That is a real advantage, and it is why the procedure appeals to older patients and those with medical conditions that make general anesthesia riskier.

What mild is not

It is not “non-surgical,” despite how it is sometimes described. Tissue and bone are removed from your spine. It is a small decompression performed through a needle-sized approach, and it should be evaluated with the same seriousness as any spine procedure.

Who Is a Good Candidate for the mild Procedure?

This is where most of the confusion lives. Lumbar spinal stenosis is not one disease. It is a narrowing that can come from several structures, and the mild procedure addresses only one of them well.

The patients it was designed for

The ideal candidate typically has:

• Neurogenic claudication: leg pain, heaviness, or numbness that comes on with standing or walking and eases when you sit or lean forward, like on a shopping cart.
• A thickened ligamentum flavum as a main source of narrowing. The pivotal clinical trials required ligament thickness greater than 2.5 mm on MRI or CT.
• Central canal stenosis rather than isolated narrowing of the side openings where nerves exit.
• Symptoms that have not responded adequately to physical therapy, medication, or injections.

When I’d look elsewhere

In my experience reviewing thousands of spine MRIs, many stenosis patients have additional problems the mild procedure cannot reach:

• Foraminal stenosis, where bone spurs or a collapsed disc pinch the nerve as it exits the spine.
• Large disc bulges or herniations pushing from the front of the canal. Those often need a disc herniation approach instead.
• Instability or meaningful slippage, such as degenerative spondylolisthesis, where removing tissue without stabilizing can make matters worse.
• Severe, multilevel stenosis with significant bony overgrowth of the facet joints.
• Back pain without the classic walking-related leg symptoms.

The honest answer for most of my patients is a mixed picture. A good evaluation tells you how much of your narrowing is ligament, how much is bone, and how much is disc. That ratio, more than any marketing claim, predicts whether mild can help you.

What the Research Actually Says About the mild Procedure Success Rate

I’ll give the mild procedure credit here. It has a stronger evidence base than many minimally invasive spine products, including two randomized controlled trials. But the details matter.

MiDAS ENCORE

This trial randomized 302 Medicare-age patients to either mild or epidural steroid injections. The published one-year results showed greater improvement in pain and function in the mild group, with a strong safety profile.

MOTION

The MOTION study randomized 138 patients to mild plus conventional medical management versus conventional management alone. At one year, disability scores improved by about 16 points with mild versus 2 points without it. The two-year results held up, and the 2026 five-year follow-up reported durable improvements, with no device- or procedure-related adverse events and fewer than 1 in 14 patients going on to open decompression or fusion.

The fine print I want patients to understand

• Neither trial compared mild with surgical decompression. The comparisons were injections and non-surgical care, which are low bars for a procedure that physically removes tissue.
• Neither trial was blinded. Patients knew which treatment they received, which can influence self-reported outcomes.
• Long-term follow-up is small. Only 39 patients in the mild group completed five-year follow-up in MOTION.
• Coverage varies. Medicare has covered the procedure under a coverage-with-evidence-development framework, while some commercial insurers still classify it as investigational.

My reading of the evidence: for carefully selected patients, mild meaningfully improves walking tolerance and pain with very low risk. What it does not prove is that mild works as well as a well-done surgical decompression for patients whose stenosis is more than ligament.

The Problem With How mild Is Often Marketed

I’ve written before about procedures that are oversold, including my warning about ultrasonic spine surgery marketing. The mild procedure is a better-studied technology, but the way it is sometimes advertised troubles me.

Myth: “It’s not surgery, so there’s no downside”

The risk of serious complications is low, and that’s genuinely good. But the bigger risk is a different one: spending months on a procedure that was never going to address your actual anatomy. For a patient with foraminal stenosis or a slipped vertebra, mild can delay the right treatment while nerves stay compressed.

Myth: “If mild doesn’t work, nothing is lost”

Physically, that’s largely true. The procedure doesn’t burn bridges, and surgery remains possible afterward. But time, money, and hope are not free, especially for an 80-year-old who is losing strength and balance every month they can’t walk.

Myth: “Everyone with stenosis qualifies”

Candidacy depends on measurable anatomy. When a clinic offers mild before anyone has carefully measured your ligament thickness and mapped the other sources of compression, that’s a red flag. The right first step is always a diagnosis, not a procedure.

None of this is a criticism of the physicians who perform mild well. Many interventional pain specialists use it thoughtfully. My point is that the procedure should be chosen to fit the anatomy, never the other way around.

mild vs. Surgical Decompression and Other Options

As a neurosurgeon, my job is to match the least invasive procedure that will actually solve the problem. Here is how I think about the main options for lumbar stenosis.

Why I often favor direct-vision decompression

For many patients, a tubular minimally invasive decompression lets me see and free the nerve completely through a small incision. I can address ligament, bone spurs, and disc material in one sitting. When the stenosis is mixed, that completeness matters.

When stability is part of the picture

If a vertebra has slipped, decompression alone can sometimes let it slip further. For select patients with mild slippage, the TOPS™ Posterior Arthroplasty System stabilizes the segment while preserving motion. When a true fusion is needed, I developed the CemLIF™ procedure, a rod-less, screw-less lumbar fusion that avoids pedicle screws altogether.

The point isn’t that one option wins. It’s that the anatomy picks the procedure. Other spine surgeons regularly send me their complex and revision cases precisely because getting that match right is the whole game.

mild Procedure Recovery Time, Risks, and What to Expect

One of the procedure’s genuine strengths is how little downtime it usually requires. Most patients go home the same day, and many return to light daily activities within a few days.

Typical recovery

• Day of procedure: outpatient, usually about an hour, with discharge the same day.
• First week: mild soreness at the access site; walking is encouraged.
• Following weeks: gradual return to normal activities, often paired with physical therapy to rebuild walking endurance.

Risks

Reported complication rates in the major trials have been very low. Like any spinal procedure, though, possible risks include bleeding, infection, a tear in the protective covering of the nerves, and nerve irritation. The most common “risk” in my view is simply that symptoms don’t improve enough because the stenosis was not primarily ligament-driven.

Questions to Ask Before You Agree to the mild Procedure

Whether you see me or another physician, these questions will tell you a lot about whether mild is being recommended for the right reasons:

1. How thick is my ligamentum flavum, and at which levels? You want measurements, not impressions.
2. What percentage of my narrowing comes from ligament versus bone or disc?
3. Do I have foraminal stenosis or any slippage? If so, how will mild address it?
4. What results do you see in patients with anatomy like mine?
5. If mild doesn’t help enough, what’s the next step, and who performs it?
6. Has a spine surgeon reviewed my imaging? A surgical opinion helps you see the full menu, not just one item on it.

Seeking an opinion from out of state

Many patients reach me from across Florida and beyond, and some winter here and live elsewhere the rest of the year. Through our Concierge Spinal Surgery Program, my team can start with a telehealth review of your imaging and coordinate scheduling, clearances, and travel if you need care in Naples.

Conclusion: Let Your Anatomy Choose the Procedure

The mild procedure earns a place in modern stenosis care. For the right patient, it can restore walking and relieve leg pain with almost no downtime. But it solves one problem, and many patients have more than one. The best outcome comes from an accurate diagnosis first and a procedure second.

If you’re dealing with spinal stenosis and want a clear diagnosis or a second opinion on whether mild is right for you, I’d encourage you to schedule a consultation. You can reach my Naples office at (239) 649-1662. If you’re traveling from out of state, inquire about our concierge program. We can start with telehealth and handle the logistics from there.

The information in this article is for educational purposes only and does not constitute medical advice. Surgical decisions are made on an individualized basis following a thorough consultation. Results may vary. Always consult a qualified physician before pursuing any surgical or medical treatment. mild® is a registered trademark of Vertos Medical, Inc.

References

1. MILD® is an effective treatment for lumbar spinal stenosis with neurogenic claudication: MiDAS ENCORE randomized controlled trial. Pain Physician. 2016. PubMed
2. Deer TR, et al. The MOTION study: two-year results of a real-world randomized controlled trial of the mild® procedure for treatment of lumbar spinal stenosis. Pain Practice. 2024. PubMed
3. The MOTION randomized controlled trial for treatment of lumbar spinal stenosis using the percutaneous mild® procedure: 5-year results. Interventional Pain Medicine. 2026. ScienceDirect
4. Centers for Medicare & Medicaid Services. Decision memo: Percutaneous image-guided lumbar decompression for lumbar spinal stenosis (CAG-00433R). CMS