MILD Procedure for Spinal Stenosis in St. Louis

MILD — minimally invasive lumbar decompression — treats one specific cause of lumbar spinal stenosis: a thickened ligamentum flavum pressing on the spinal canal from behind.

Through an incision smaller than the diameter of a dime, and under live X-ray guidance, a small portion of the overgrown ligament and a sliver of bone are removed. That restores space in the canal without implants, without general anesthesia, and without destabilizing the spine. Medicare classifies it as percutaneous image-guided lumbar decompression, or PILD.

The distinction that matters: MILD is indirect decompression performed under image guidance, not open surgery under direct visualization. Traditional laminectomy and endoscopically assisted laminotomy are different procedures, with different risks, different recovery, and a different insurance status entirely.

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Lumbar spinal stenosis is the most common reason older adults have spine surgery. The classic pattern is neurogenic claudication: legs that ache, burn, or go heavy after a few minutes of walking, and settle when you sit or lean forward over a cart.

That leaning is diagnostic. Bending forward opens the spinal canal; standing upright closes it. Patients who can walk a supermarket but not a parking lot are describing stenosis.

MILD only addresses stenosis driven by ligamentum flavum hypertrophy. Stenosis from a large disc herniation, from spondylolisthesis with instability, or predominantly from bony overgrowth in the lateral recess will not respond to it. Establishing which stenosis you have — through examination and imaging review, not assumption — is the whole of candidate selection.

The honest answer is that the evidence is positive, consistent, and moderate in quality. It is not the evidence base of a decades-old operation, and we would rather say so than oversell it.

A 2025 systematic review and meta-analysis in Pain Physician pooled 12 clinical trials covering 500 patients. It found a statistically significant reduction in pain scores and in Oswestry Disability Index scores against baseline, with adverse events low compared with other surgical decompression techniques. The authors conclude MILD is effective and safe, and explicitly call for more well-designed randomized trials.

A 2023 review in the Journal of Pain Research put ranges on it. Visual analog pain scores fell from a pre-treatment 6.3–9.6 to a post-treatment 2.3–5.8, and Oswestry Disability Index scores from 38.8–55.3 to 27.4–39.8, with reported effective rates of 57–88 percent and benefit shown to remain stable at two years. One randomized trial within that review found MILD superior to epidural steroid injection.

Those effective-rate ranges are wide — 57 to 88 percent — and the reason matters. The studies did not share inclusion and exclusion criteria, and did not standardize what conservative treatment came first or for how long. Outcomes were measured with self-reported scoring tools, which are subject to bias. Long-term efficacy beyond roughly two years is not established by the current literature.

Trials of this kind also routinely exclude the patients this practice most often sees: people with significant metabolic disease, several pain generators at once, prior spine surgery, or complex medication histories. A 57–88 percent range derived from cleaner study populations is a starting point for a conversation about your spine. It is not a prediction about it.

Ruling MILD out is as much of the work as ruling it in. It is generally not appropriate where:

• Stenosis is not driven primarily by a thickened ligamentum flavum
• There is spondylolisthesis with instability, where decompression alone can worsen the slip
• A large disc herniation or bony lateral recess stenosis is the dominant compression
• Cauda equina syndrome, a progressive neurological deficit, or bowel or bladder involvement is present — these are urgent, and are not managed with an elective outpatient decompression
• There is active infection, uncorrected bleeding risk, or anticoagulation that cannot be safely interrupted
• Imaging and symptoms disagree, and that disagreement has not been resolved

MILD is performed as an outpatient procedure under local anesthetic with mild sedation. There is no implant left behind, no fusion, and no general anesthesia.

In order: an IV is placed and a light sedative given, you are positioned on the procedure table, and your back is numbed with a local anesthetic. The decompression is done through a small portal under live X-ray guidance. Most patients go home the same day.

Because mild sedation is used, arrange for someone to drive you home. That is specific to this procedure — most of the injection-based treatments here use no sedation at all, and those patients drive themselves.

Afterwards, keep the site clean and dry, and plan on a follow-up visit within five to ten days so the result can be assessed directly rather than over the phone. Do not lift anything over 20 pounds for two weeks. That is the main restriction, and it is short — because MILD leaves no implant and no cement, there is nothing that has to consolidate before you resume normal loading.

That two-week window is worth understanding when you compare options. A fusion commits you to months of restricted lifting while bone knits. MILD does not, because nothing was fused.

Medicare’s national coverage determination for percutaneous image-guided lumbar decompression covers this procedure only for patients enrolled in an approved clinical study. At this practice, MILD is offered as a self-pay service. You are told that before anything is scheduled, you sign an advance beneficiary notice, and you know your position in writing before you commit to anything. Commercial policies vary and are checked individually.

That is a payment decision, not a clinical one. A coverage determination describes what a payer will fund. It is not a finding about whether a procedure helps a particular patient, and it does not revise the published outcomes above. The two questions are genuinely separate, and it is worth being clear about which one you are asking.

We do not publish prices, because what any given patient needs is established at evaluation and varies. Call (314) 481-5000 and we will tell you plainly what applies to you before you decide anything.

MILD is not a first step, and it is not a last resort.

We work conservatively first — activity modification, physical therapy, and the metabolic drivers that make spinal degeneration worse. Where that is not enough, image-guided epidural steroid injections are used both to treat and to localize the pain generator.

There is published support for not stalling at that stage. A 2021 study in Pain Management compared patients who had one or no epidural steroid injection before MILD against those who had two or more. Outcomes were similar in both groups, leading the authors to conclude that repeated injections beforehand did not improve results and may have delayed care.

Surgery remains available, and this practice performs it — Dr. Gurpreet Singh Padda, MD, MBA, MHP is a licensed physician and surgeon with surgical privileges. For lumbar spinal stenosis specifically, MILD sits between injections and open decompression: a smaller intervention that preserves every later option, including spinal cord stimulation, because nothing is implanted and no structural bone is compromised.