After 27 years of treating disc patients with VAX-D spinal decompression, I can tell you with confidence that patient selection is the most important variable in the entire treatment equation. The right patient on a VAX-D table gets better. The wrong patient doesn’t — and that failure gets attributed to decompression therapy rather than to a selection error.
So here is the most direct version of the candidacy question I can give you, based on nearly three decades of watching who responds and who doesn’t.
The Conditions VAX-D Is Designed to Treat
VAX-D produces its clinical effects through two primary mechanisms: negative intradiscal pressure (which retracts herniated disc material and reduces nerve compression) and disc rehydration (which draws fluid and nutrients back into dehydrated disc tissue). Both mechanisms require an intact or partially intact disc to work on.
The diagnoses that align with these mechanisms:
Lumbar disc herniation: The strongest indication. Herniated disc material — nucleus pulposus that has pushed through the outer annulus — can be retracted by the negative pressure VAX-D creates. If that herniated material is compressing a nerve root and causing radiculopathy (pain, numbness, or weakness into the leg), successful retraction can produce rapid, dramatic symptom relief. This is where we see the most consistent outcomes.
Lumbar disc bulge: Similar mechanism, somewhat less dramatic results in most cases because the disc material hasn’t fully extruded. Bulge with superimposed radiculopathy responds well. Bulge without clear nerve compression is a softer indication — discogenic pain may improve, may not.
Degenerative disc disease with disc involvement: The rehydration mechanism is the relevant one here. Patients with disc dehydration and loss of disc height — particularly at one or two levels — can show improved disc hydration and pain reduction. Response is slower and less predictable than for herniation, and outcomes are more variable.
Discogenic low back pain: Axial low back pain that originates in the disc itself (worse with sustained sitting, bending, Valsalva; better with lying down or changing position) often responds to decompression even without clear radiculopathy. The disc itself is the pain generator, and unloading it reduces its pain output.
Facet joint pain with disc involvement: Disc degeneration and loss of height loads the facet joints excessively. Distraction reduces facet loading and can improve facet-mediated pain as a secondary effect.
The Candidacy Checklist
This is the mental checklist I run through when evaluating whether VAX-D is appropriate for a new patient:
✓ Disc-mediated pathology is the primary pain generator
The most important question. If the pain is primarily from a disc (herniation, bulge, DDD, discogenic), decompression addresses the mechanism directly. If the primary pain generator is something else — sacroiliac joint dysfunction, piriformis syndrome, hip arthritis, facet syndrome without disc involvement — decompression may not address the actual source.
✓ MRI confirms disc pathology at the symptomatic level
We never start decompression without imaging review. The clinical symptoms should match the imaging finding — a left L5-S1 herniation in a patient with left leg pain makes sense. A large herniation on MRI in a patient with unrelated symptoms doesn’t.
✓ No absolute contraindications on imaging
We screen for: spinal instability or spondylolisthesis Grade 2+, pathological fracture, active malignancy in the spine, significant osteoporosis (DEXA T-score below -2.5 at the treatment level), aortic aneurysm, and certain surgical hardware configurations. Any of these rules out VAX-D.
✓ Symptoms have a mechanical character
Pain that worsens with loading (standing, walking, sitting), improves with unloading (lying down, changing position), and is clearly positional suggests a mechanical pain source that responds to mechanical interventions. Constant, non-positional pain or pain that is worse at rest than with activity suggests a non-mechanical component that needs additional evaluation.
✓ The acute phase has settled enough to tolerate treatment
Patients in severe acute crisis — unable to tolerate any position, significant neurological deficit — need acute management first. A patient who can lie comfortably for 30-40 minutes is ready for evaluation. A patient who can’t sit for five minutes without agonizing pain may need a brief course of acute care before starting decompression.
✓ Willingness to complete the full protocol
Decompression is a series, not a single treatment. 15-20 sessions over 5-6 weeks is the standard protocol. Patients who want a “try one session and see” approach are almost certainly going to be disappointed — the cumulative rehydration and decompression effects build over the course of treatment. One session doesn’t tell you much.
Who Typically Doesn’t Respond Well
Equal clinical value lives in knowing when to say no:
Severe, sequestered herniations: A disc fragment that has completely separated from the parent disc and migrated into the canal behaves differently than an extrusion still connected to the disc. Sequestered fragments may not retract under negative pressure, and some require surgical removal. We identify these on imaging and discuss surgical consultation when appropriate.
Primarily bony stenosis: Bone doesn’t retract. If canal narrowing is predominantly from osteophytes, thickened ligamentum flavum, or hypertrophic facets with minimal disc contribution, the mechanism that makes VAX-D effective for disc herniation doesn’t apply cleanly.
Significant neurological deficits: Foot drop, progressive leg weakness, bowel or bladder dysfunction — these are red flags for severe nerve compression that needs urgent surgical evaluation, not conservative care. We identify these in history and examination and refer when present.
Primarily non-mechanical pain sources: Sacroiliac joint dysfunction, piriformis syndrome, hip arthritis, and femoral nerve issues can all mimic disc radiculopathy. If diagnostic testing suggests the disc isn’t the primary pain generator, treating the disc mechanically won’t resolve symptoms.
Anxiety about the treatment itself: This one is underappreciated. Patients who are very anxious about being on the table, who guard strongly against the harness, or who cannot fully relax during treatment don’t allow the distraction force to work effectively. The lumbar paraspinal muscles will resist the distraction if the patient is guarding, which limits the intradiscal pressure changes. If a patient is this anxious, we work on that first.
The Honest Number
In our experience treating disc patients since 1997: roughly 70-75% of appropriately selected patients achieve clinically meaningful improvement from a full course of VAX-D. About 20-25% see partial benefit. The remaining 5-10% don’t respond meaningfully.
Those numbers hold up reasonably well against published research on the topic. But they depend on appropriate selection. The practices reporting 85-90% success rates are either treating only the most ideal candidates or defining “success” loosely. The practices reporting 50% success rates are likely undertreating (poor protocol adherence) or over-selecting (treating patients outside the ideal indication range).
We’d rather quote you a real number and work from there than promise you something we can’t deliver.
Find Out Where You Fall
The candidacy evaluation is the most important conversation we have with any new patient. Bring your imaging, your history, your list of what you’ve tried. We’ll tell you — directly — whether VAX-D is likely to help your specific case.
Call 631-659-2980 or schedule your evaluation online. West Hills Chiropractic Pain Center, 400 W Jericho Turnpike, Huntington, NY 11743.
— Dr. Tom Oddo, DC CSCS CEAS, West Hills Chiropractic Pain Center