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Grade 1 Spondylolisthesis and Meyerding Grades I–V: What the Slip Grade Means

Written by Ifije Ohiorhenuan, MD, PhD — Board-Certified Spine Neurosurgeon. Last updated 2026-07-03.

Grade 1 spondylolisthesis means one vertebra has slipped forward by less than 25% compared with the bone below it, and by itself it does not automatically mean you need surgery or that your spine is unstable.

If you saw “Grade 1 spondylolisthesis,” “anterolisthesis,” or “Meyerding Grade I” on a report, it can sound alarming — many people picture a bone sliding out of place. Grade 1 is the mildest category. What matters more is whether the slip matches your symptoms, pinches a nerve, or moves too much.

What Does “Grade 1 Spondylolisthesis” Mean?

Spondylolisthesis means one vertebra (a bone in your spine) has slipped compared with the vertebra below it. Anterolisthesis means it slipped forward. Reports often use the two terms interchangeably for a forward slip, and the exact wording varies between radiologists.

Grade 1 means the slip is less than 25% of the width of the vertebral body, the large front part of the spinal bone. It is the mildest Meyerding grade.

In my practice, I tell patients that Grade 1 is a measurement, not a diagnosis: it does not tell us how much pain you should have, whether a nerve is pinched, or whether surgery is needed.

For a broader overview, see Spondylolisthesis: When the Bones Slip.

The Meyerding Classification: Grades I Through V

The Meyerding classification grades spondylolisthesis by how far one vertebral body has slipped forward relative to the vertebra below.

You may see the grade on a standing X-ray, an MRI (uses magnets to show soft tissues and nerves), or a CT scan (uses X-rays to show bone detail).

Meyerding Grade Amount of Slip Plain-English Meaning
Grade I 0–25% Mild slip
Grade II 25–50% Moderate slip
Grade III 50–75% More significant slip
Grade IV 75–100% Severe slip
Grade V More than 100% Spondyloptosis; the upper vertebra has slipped completely beyond the one below

Spondyloptosis means a slip of more than 100% (Grade V). It is uncommon and very different from the typical Grade 1 finding many people see on reports.

Does a Higher Grade Always Mean More Pain?

No. A higher grade can matter more structurally, but the grade does not track pain severity. Some people with Grade 1 have significant symptoms, often when the slip narrows the spaces for nerves or adds to stenosis (narrowing around the spinal canal or nerve pathways). Others with low-grade slips have little pain or none.

Pain can come from many places, including:

  • Discs, which are the cushions between the vertebrae
  • Facet joints, which are small joints in the back of the spine
  • Nerves
  • Muscles
  • The sacroiliac joint, which is the joint between the spine and pelvis
  • Other sources outside the spine

What Doctors Look For Besides the Slip Grade

The grade is only part of the story. A small slip can matter if it crowds a nerve; a larger slip may cause fewer symptoms if the nerves still have room. On MRI, what I look for is whether the slip is narrowing the spaces where nerves travel.

Nerve compression

Nerve compression means a nerve is being squeezed or crowded. A slip can contribute to several types of narrowing:

If a nerve root is irritated, you may feel sciatica — pain, tingling, numbness, or weakness that travels from the low back or buttock into the leg along a nerve path. Learn more in Sciatica: Causes, Diagnosis, and the Treatment Path.

The finding matters most when the patient’s symptoms match the level and side of the nerve compression.

Stable or mobile?

Instability usually means abnormal motion between two vertebrae. It does not mean every small slip is dangerous. MRI shows anatomy well, but it is usually done while you are lying still, so it may not show whether the slipped level moves too much when you stand, bend, or extend. Flexion-extension X-rays — standing films taken while you bend forward and backward — can show that motion when the question matters. If I am worried about motion at the slipped level, I consider them.

Degenerative or isthmic?

The cause of the slip matters. Degenerative spondylolisthesis comes from wear-and-tear changes in the disc and facet joints, more common in older adults and often at L4-L5 (the level between the fourth and fifth lumbar vertebrae in the low back).

Isthmic spondylolisthesis comes from a defect or stress fracture in the pars interarticularis, a small bridge of bone in the back part of the vertebra. It often happens at L5-S1 (the level between the lowest lumbar vertebra and the sacrum, the bone at the base of the spine).

Both involve a slip, but they are different problems, with different patterns and treatment choices.

For more on the condition itself, see Spondylolisthesis: When the Bones Slip.

Do the symptoms match the imaging?

Back pain alone is different from leg pain, numbness, weakness, or trouble walking. A Grade 1 slip at L4-L5 matters more when your symptoms match L4 or L5 nerve compression, but the report phrase alone cannot prove the pain source. A radiology report describes the scan; it does not know your pain pattern, strength exam, reflexes, or walking limits.

Grade 1 Spondylolisthesis: Is It Serious?

Grade 1 is low-grade, the mildest Meyerding category, and many people with it are treated without surgery, especially when there is no progressive weakness, severe nerve compression, or disabling limitation.

But Grade 1 is not automatically “nothing.” Its seriousness depends on the full picture: your symptoms; your neurologic findings (strength, feeling, reflexes, and walking function); whether nerves are compressed; whether there is spinal stenosis; whether the slip is stable, mobile, or changing over time; and how much the symptoms limit your life. A Grade 1 slip with mild or no symptoms is very different from one with progressive weakness or severe stenosis.

Does Grade 1 Spondylolisthesis Get Worse?

Some Grade 1 slips stay stable over time; others progress. The risk is not the same for everyone and can depend on age, the cause and spinal level of the slip, disc wear, facet joint arthritis, whether the slip is degenerative or isthmic, and whether the level shows abnormal motion.

Not every Grade 1 slip needs repeated imaging. Follow-up may be considered when symptoms change, new neurologic findings appear, or a clinician is monitoring known or suspected instability. A change in symptoms often matters more than the number alone.

How Spondylolisthesis Is Usually Treated

This is a high-level overview, not a personal treatment plan. Many low-grade slips are first treated without surgery. Common options may include:

  • Activity changes to reduce painful positions or loads
  • Physical therapy focused on core strength, hip strength, flexibility, and movement mechanics
  • Anti-inflammatory medicines when appropriate and approved by the patient’s clinician
  • Injections in selected cases, especially when nerve irritation or stenosis is suspected
  • Surgery in selected cases when symptoms are persistent and disabling, neurologic deficits are present, or instability or stenosis is significant

Anti-inflammatory medicines reduce inflammation and pain, and may not be safe for everyone. Injections place medicine near an irritated nerve or painful spinal area to reduce inflammation, and are not the right choice for every person.

I do not recommend treatment based on the word “spondylolisthesis” alone. I look at the patient’s pain pattern, neurologic exam, imaging, and how much the symptoms are limiting life, not the Meyerding grade.

For a deeper treatment overview, see Spondylolisthesis: When the Bones Slip.

Why Your MRI Report May Sound Scarier Than the Finding Is

Radiology reports use technical language. Words like “listhesis,” “spondylolisthesis,” and “anterolisthesis” can sound worse than the measurement actually is.

Listhesis simply means slippage, a description of alignment.

Your report may also list several degenerative findings, meaning wear-and-tear or age-related change. These are common on spine imaging, even in some people without pain.

Most reports list some abnormalities. What matters is which of them, if any, explain your symptoms:

Which findings, if any, explain your symptoms?

For help with MRI wording, see How to Read Your Spine MRI Report.

If you are confused by similar-sounding terms, see Spondylosis vs. Spondylolisthesis vs. Spondylolysis: The Three “Spondy” Words.

If your report says the vertebra slipped backward instead of forward, see Retrolisthesis: When the Vertebra Slips Backward.

When to Seek Urgent Medical Care

This article and SpineClarity’s written MRI/case review are not for emergencies.

Seek urgent medical care now if you have:

  • New or worsening leg weakness
  • Numbness in the groin, genitals, buttocks, or saddle area
  • Loss of bladder control
  • Loss of bowel control
  • New trouble starting urination with severe back or leg symptoms
  • Rapidly worsening numbness, weakness, or walking trouble
  • Fever, chills, or feeling very ill with severe back pain
  • Severe back pain with infection risk, such as IV drug use, immune suppression, recent spine procedure, or active infection elsewhere
  • Severe back pain with a known history of cancer or unexplained weight loss
  • Severe pain after a major fall, accident, or trauma
  • Back pain with possible fracture risk, especially in older adults or people with osteoporosis or long-term steroid use

Cauda equina syndrome is a spine emergency where nerves at the bottom of the spinal canal are severely compressed. It can cause bladder or bowel changes, saddle numbness, leg weakness, or severe nerve symptoms.

If symptoms are rapidly worsening, do not wait for an online review. Possible cauda equina symptoms require immediate emergency evaluation.

Learn more in Cauda Equina Syndrome: The Spine Emergency Patients Need to Recognize.

When a Written MRI/Case Review Can Help

If your report says “Grade 1 spondylolisthesis,” “anterolisthesis,” or “Meyerding Grade I” and you are not sure whether it explains your symptoms, SpineClarity can help. A board-certified spine surgeon can review your symptoms, MRI report, and records and provide a plain-language written interpretation with a suggested next-step category. This is not emergency care and does not replace an in-person physician relationship.

Frequently Asked Questions

Does Grade 1 spondylolisthesis require surgery?

Usually not on the grade alone. Most Grade 1 slips are managed without surgery, which is reserved for selected cases: persistent disabling symptoms, progressive neurologic problems, significant stenosis, or instability.

Can Grade 1 spondylolisthesis cause sciatica?

Yes, if it narrows the space for a nerve or irritates a nerve root. But sciatica can also come from other causes, such as a disc herniation or spinal stenosis.

References

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Spondylolisthesis. StatPearls. NCBI Bookshelf. Treasure Island, FL: StatPearls Publishing. Updated regularly. https://www.ncbi.nlm.nih.gov/books/

North American Spine Society. Diagnosis and Treatment of Degenerative Lumbar Spondylolisthesis: Evidence-Based Clinical Guidelines. 2nd ed. Burr Ridge, IL: North American Spine Society; 2014.

North American Spine Society. Diagnosis and Treatment of Adult Isthmic Spondylolisthesis: Evidence-Based Clinical Guidelines. Burr Ridge, IL: North American Spine Society; 2014.

Kalichman L, Hunter DJ. Diagnosis and conservative management of degenerative lumbar spondylolisthesis. European Spine Journal. 2008;17(3):327–335. doi:10.1007/s00586-007-0543-3

Cavalier R, Herman MJ, Cheung EV, Pizzutillo PD. Spondylolysis and spondylolisthesis in children and adolescents: I. Diagnosis, natural history, and nonsurgical management. Journal of the American Academy of Orthopaedic Surgeons. 2006;14(7):417–424.

Sengupta DK, Herkowitz HN. Degenerative spondylolisthesis: review of current trends and controversies. Spine. 2005;30(6 Suppl):S71–S81.

Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis. New England Journal of Medicine. 2007;356(22):2257–2270. doi:10.1056/NEJMoa070302

Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical compared with nonoperative treatment for lumbar degenerative spondylolisthesis: four-year results in the Spine Patient Outcomes Research Trial. Journal of Bone and Joint Surgery American Volume. 2009;91(6):1295–1304. doi:10.2106/JBJS.H.00913

Brinjikji W, Luetmer PH, Comstock B, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR American Journal of Neuroradiology. 2015;36(4):811–816. doi:10.3174/ajnr.A4173

Boden SD, Davis DO, Dina TS, Patronas NJ, Wiesel SW. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. Journal of Bone and Joint Surgery American Volume. 1990;72(3):403–408.

American College of Radiology. ACR Appropriateness Criteria® Low Back Pain. Revised 2021. https://acsearch.acr.org/

Gardner A, Gardner E, Morley T. Cauda equina syndrome: a review of the current clinical and medico-legal position. European Spine Journal. 2011;20(5):690–697. doi:10.1007/s00586-010-1668-3

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