Imaging and Grading Your Spine

At a Glance

Spondylolisthesis imaging shows how far a vertebra has slipped, whether the spine moves with position, and whether nerves are narrowed. The Meyerding grade describes the slip on an image, but it does not by itself predict pain or determine treatment.

Getting a clear picture of your spine is the first step in understanding why a vertebra has shifted. While an X-ray or MRI report may contain complex terms, the goal of imaging is simple: to determine how far the bone has moved, whether it is stable, and if it is pressing on any nerves ^[1]^[2].

Tools That May Be Considered

There is no universal “complete imaging set.” Your doctor will select imaging based on your symptoms, examination, prior images, and whether an intervention is being considered.

Standing X-rays: When you stand, gravity and the weight of your body put natural pressure on your spine. This can cause a slip to appear more significant than it would if you were lying down ^[3]^[4].
Supine (Lying Down) MRI: Most MRIs are performed while you are lying flat on your back. Research shows that this position can sometimes “reduce” the slip, making it look smaller on the scan ^[2]^[4]. However, a supine MRI remains incredibly valuable for seeing the soft tissues, nerves, and discs.
Dynamic Imaging: Your doctor may request flexion-extension X-rays, which are taken while you bend forward and backward. These help identify “instability,” though the utility varies and there is no universally accepted instability threshold ^[5]^[6].
CT Scan: Best for looking at the bone itself. It can be useful for finding a pars defect—the small stress fracture often seen in isthmic spondylolisthesis—but it involves radiation and is not routinely needed just to classify a known degenerative slip ^[7]^[8].

The Meyerding Grading System

To help doctors communicate how far a vertebra has slipped, they use the Meyerding Classification. This system divides the top of the lower vertebra into four equal quarters and measures how far the upper vertebra has traveled over it ^[9].

Grade	Slip Percentage	Description
Grade I	0% – 25%	A mild slip.
Grade II	26% – 50%	A moderate slip.
Grade III	51% – 75%	A severe slip.
Grade IV	76% – 100%	A very severe slip.
Grade V	> 100%	Also called spondyloptosis, where the bone has slipped completely off.

It is critical to remember that the “Grade” describes the appearance on the X-ray, not your level of pain. Grade alone does not reliably predict pain or neurologic symptoms, and it does not determine your treatment or follow-up imaging on its own ^[10]^[11].

Deciphering Your Imaging Report

When you read your report, you may see these common terms:

Listhesis: A general term for a slip. Anterolisthesis means a forward slip, while retrolisthesis means a backward slip ^[3].
Stenosis: Narrowing of the spaces for nerves. This can occur in the central canal, the lateral recess (the side pockets inside the spinal canal just before the nerve exits), or the foraminal space (the actual doorways where nerves leave) ^[1].
Facet Arthropathy: Arthritis or wear-and-tear in the small joints of the spine ^[8].
Facet Effusion: Fluid buildup in the spinal joints. Doctors often see this as an association that may suggest motion, but it does not establish instability by itself ^[12]^[13].
Pars Defect: A break or gap in the bridge of bone at the back of the vertebra ^[7].

Patient Discussion Guide

Instead of treating imaging as an absolute checklist, use these questions with your doctor:

“Ask why this test is needed, what decision it will change, and whether a prior scan is sufficient.”
“Does the severity on my imaging actually match the symptoms I am feeling?”

Common questions in this guide

What does my Meyerding grade mean for spondylolisthesis?

The Meyerding system estimates how far one vertebra has slipped over the vertebra below it: Grade I is 0–25%, Grade II is 26–50%, Grade III is 51–75%, Grade IV is 76–100%, and Grade V is more than 100% and called spondyloptosis. This grade describes the appearance on an image and does not measure your pain.

Can standing X-rays and a lying-down MRI show different amounts of slippage?

Standing X-rays show the spine while it bears your body weight, so a slip can look larger. Most MRI scans are done lying flat, which can make the slip look smaller, but MRI provides important detail about discs, soft tissues, and nerves. The two tests answer different questions and may both be useful.

How can doctors tell whether spondylolisthesis is unstable?

Doctors may use flexion-extension X-rays, taken while you bend forward and backward, to look for movement between positions. They may also compare standing and lying-down images. There is no universally accepted single measurement that defines instability, so the result is interpreted with your symptoms and examination.

What do stenosis, facet arthropathy, and a pars defect mean on my report?

Stenosis means narrowing around the spinal nerves, including the central canal, lateral recess, or foraminal space. Facet arthropathy means arthritis or wear in the small spinal joints, while a pars defect is a break or gap in bone at the back of a vertebra. Facet fluid, called facet effusion, may suggest motion but does not prove that the spine is unstable.

Does a higher spondylolisthesis grade explain my pain or determine treatment?

No. The Meyerding grade describes how the slip looks on imaging, but it does not reliably predict pain or neurologic symptoms. Treatment and decisions about follow-up imaging also depend on your symptoms, examination, nerve narrowing, stability, and other findings.

Get notified when new evidence is published on spondylolisthesis.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.

References (13)

1
Reliability of standing weight-bearing (0.25T) MR imaging findings and positional changes in the lumbar spine.
Hansen BB, Hansen P, Christensen AF, et al.
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PMID: 28812185
2
Weight-bearing MRI of the Lumbar Spine: Spinal Stenosis and Spondylolisthesis.
Hansen BB, Nordberg CL, Hansen P, et al.
Seminars in musculoskeletal radiology 2019; (23(6)):621-633 doi:10.1055/s-0039-1697937.
PMID: 31745952
3
Correlation of listhesis on upright radiographs and central lumbar spinal canal stenosis on supine MRI: is it possible to predict lumbar spinal canal stenosis?
Finkenstaedt T, Del Grande F, Bolog N, et al.
Skeletal radiology 2018; (47(9)):1269-1275 doi:10.1007/s00256-018-2935-3.
PMID: 29651713
4
Assessing the Differences in Measurement of Degree of Spondylolisthesis Between Supine MRI and Erect X-Ray: An Institutional Analysis of 255 Cases.
Alvi MA, Sebai A, Yolcu Y, et al.
Operative neurosurgery (Hagerstown, Md.) 2020; (18(4)):438-443 doi:10.1093/ons/opz180.
PMID: 31381804
5
Lumbar Facet Fluid-Does It Correlate with Dynamic Instability in Degenerative Spondylolisthesis? A Systematic Review and Meta-Analysis.
Aggarwal A, Garg K
World neurosurgery 2021; (149()):53-63 doi:10.1016/j.wneu.2021.02.029.
PMID: 33607287
6
Do We Have Adequate Flexion-extension Radiographs for Evaluating Instability in Patients With Lumbar Spondylolisthesis?
Morita T, Yoshimoto M, Terashima Y, et al.
Spine 2020; (45(1)):48-54 doi:10.1097/BRS.0000000000003203.
PMID: 31415456
7
Utility of standing radiographs in the evaluation of refractory low back pain and lumbar radiculopathy following a lumbosacral fusion: illustrative case.
Wetsel ZP, Wadhwa A, Sconzo D, Binello E
Journal of neurosurgery. Case lessons 2025; (9(9)).
PMID: 40030165
8
Association of CT-based facet joint degeneration with low back pain and spinopelvic parameters in grade I L4-5 degenerative lumbar spondylolisthesis.
Zehua J, Xin T, Hongjie Z, et al.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia 2026; (154()):112268 doi:10.1016/j.jocn.2026.112268.
PMID: 42691719
9
Lumbar Spondylolisthesis Grading: Current Standards and Important Factors to Consider for Management.
Daher M, Rezk A, Baroudi M, et al.
World neurosurgery 2024; (190()):311-317 doi:10.1016/j.wneu.2024.07.194.
PMID: 39094941
10
Association of Lumbar Spondylolisthesis With Low Back Pain and Symptomatic Lumbar Spinal Stenosis in a Population-based Cohort: The Wakayama Spine Study.
Ishimoto Y, Yoshimura N, Muraki S, et al.
Spine 2017; (42(11)):E666-E671 doi:10.1097/BRS.0000000000001960.
PMID: 27779607
11
Lumbar Spinal Stenosis in Older Adults.
Lafian AM, Torralba KD
Rheumatic diseases clinics of North America 2018; (44(3)):501-512 doi:10.1016/j.rdc.2018.03.008.
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12
Magnetic Resonance Imaging Proxies for Segmental Instability in Degenerative Lumbar Spondylolisthesis Patients.
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Spine 2022; (47(21)):1473-1482 doi:10.1097/BRS.0000000000004437.
PMID: 35877558
13
Quantitative Facet Joint Effusion on Magnetic Resonance Imaging Is Associated With Dynamic Segmental Instability and Pain Severity in Degenerative Lumbar Spondylolisthesis.
Zhao YL, Si HP, Sun YG
Journal of clinical medicine research 2026; (18(6)):369-378 doi:10.14740/jocmr6572.
PMID: 42490835

This page explains spondylolisthesis imaging and Meyerding grades for informational purposes only and does not constitute medical advice. Your clinician should interpret your scans alongside your symptoms and examination.