Spondylolisthesis and Retrolisthesis: What the Grades Mean

Quick answer: Both words describe one vertebra sitting out of line with the one below it. Spondylolisthesis is a forward slip; retrolisthesis is a backward slip. Severity is described in grades based on how far it has moved, and Grade 1 — a slip of 25% or less — is by far the most common and the mildest. Plenty of people have one and never know, because a slip on a scan does not reliably mean pain.

If you are here because a radiology report used one of these words, the grade and the direction are probably what you want first, so they come first.

Spondylolisthesis and Retrolisthesis: the Difference Is Direction

The root listhesis means slipping. Everything in front of it tells you which way.

Spondylolysis matters because it can precede a slip: if the pars fracture stops holding, the vertebra above it may drift forward, and the spondylolysis becomes an isthmic spondylolisthesis. They are often discussed together for that reason, and spondylolysis has its own page here.

Retrolisthesis is usually degenerative. As a disc loses height and the surrounding ligaments slacken, the vertebra can settle backward. It commonly appears alongside disc degeneration on the same scan, which is part of why it is often reported and rarely acted on by itself.

The Grades, Explained

Grading uses the Meyerding system, which simply asks how far the vertebra has moved as a percentage of the width of the vertebra below it.

What Grade 1 actually means

It means the slip is a quarter of the vertebral width or less. In practical terms, that is the mildest category there is, and it is the grade most people are told they have.

It does not tell you how much pain you should expect, because grade and symptoms correlate poorly. It does not mean you are heading for surgery — standard management of a low-grade slip starts with conservative care, and the large majority never need an operation. And it does not mean you should stop moving. What it does mean is that the finding is worth understanding rather than worrying about in the abstract, and that questions about your particular case belong with the physician who ordered the scan.

The same percentage bands are generally used for describing retrolisthesis, so “grade 1 retrolisthesis” carries the same meaning in the other direction.

What Your Imaging Report Does and Does Not Tell You

This is the part most people need and rarely get, so it is worth being direct about.

A systematic review in the American Journal of Neuroradiology looked at spinal imaging in people with no symptoms at all. Disc degeneration appeared in 37% of asymptomatic 20-year-olds and 96% of asymptomatic 80-year-olds. Disc bulges ran from 30% to 84% across the same span. Spondylolisthesis showed up in 23% of asymptomatic people by age 60.

The authors’ conclusion was that many of these features are likely part of normal aging and unassociated with pain.

Degenerative spondylolisthesis follows the same pattern. A systematic review of its epidemiology found it uncommon before age 50 and then rising steeply, reaching roughly a quarter of women and a fifth of men over 65 in one large population, and noted that it is commonly seen as an incidental finding in people without symptoms.

None of this means your pain is imaginary. It means the slip on the report and the pain in your back are two separate facts that have to be connected by a clinician, not assumed to be cause and effect. Some slips are clearly responsible for symptoms. Others are bystanders that happened to be in the picture.

The Types, and Why They Are Treated Differently

Spondylolisthesis is classified by cause as well as by grade, which matters because the causes behave differently over time.

• Degenerative — the most common in older adults. Disc and facet joint wear lets the vertebra drift. Typically slow, and often stable.
• Isthmic — follows a pars stress fracture, often originating in adolescence from repeated extension loading in sports like gymnastics, diving, throwing and football. Affects roughly 4–8% of adults.
• Dysplastic — a congenital difference in the shape of the vertebra or facet joints. Less common, watched more closely in children.
• Traumatic — a fracture from significant force.
• Pathologic — bone weakened by systemic disease such as a tumor or infection.

Symptoms, and the Signs That Need Prompt Attention

Many slips are silent. When they do produce symptoms, the usual picture is low back pain that is worse with standing, walking and extension, and easier with sitting or leaning forward. Some people notice hamstring tightness, a change in how they stand, or leg symptoms if a nerve root is involved.

Seek medical attention promptly for any of the following:

• Numbness or tingling in the groin or inner thighs, or new difficulty controlling your bladder or bowels — this needs emergency assessment
• Weakness in a leg or foot, or a foot that catches or drops when you walk
• Leg pain that is worsening, or that has replaced the back pain
• Back pain following significant trauma
• Night pain that wakes you, fever, or unexplained weight loss
• A known slip that appears to be progressing, particularly in a child or adolescent

These are not reasons to panic. They are reasons the question belongs with a physician rather than with exercise.

How a Slip Is Usually Treated

For low-grade slips, conservative care is first-line: activity modification, anti-inflammatory medication where appropriate, physical therapy, and sometimes bracing. Only a minority go on to surgery — one figure cited for younger patients who do not respond to conservative care is around 10–15%.

High-grade slips, and slips producing progressive neurological symptoms or significant spinal stenosis, are a different conversation, and one for a spine surgeon rather than anyone in the movement world.

An orthopedist or spine specialist is the right clinician to grade your case, decide whether it needs monitoring, and say what is safe for you specifically.

Where Posture Therapy Fits, and Where It Does Not

Posture work does not reduce a slip. Once a vertebra has moved, no exercise puts it back, and any practitioner implying otherwise is overreaching. Grade is a structural measurement, and it is not what we change.

What can change is the load going through the segment and the way the rest of you organizes around it. A lumbar spine that lives in constant extension, a pelvis tipped hard forward, hips that do not extend so the low back does the work instead — these affect how much the affected level is asked to absorb during an ordinary day. That is ordinary musculoskeletal territory and it is where we work. The Activ8 Posture Method page describes how the assessment runs.

Two things to know. First, conservative care for spondylolisthesis is well established, and several exercise approaches work; no single protocol has been shown to be best, so the right program is the one matched to you. Second, some movements load a slip more than others, depending on your type and grade; isthmic slips in particular tend to dislike repeated end-range extension. That is a good reason to get guidance specific to your case rather than follow a generic routine.

So the sequence we would suggest is: get it graded, ask your physician what is safe, and then work on load and movement within those limits.

This article is for general education and is not medical advice. A slip should be assessed by a physician — an orthopedist or spine specialist for grading and management decisions. Do not change prescribed treatment based on anything you read here.

Frequently Asked Questions

What is spondylolisthesis in simple terms?

One vertebra has slipped forward out of line with the one below it. It is graded by how far it has moved, from Grade I (25% or less) to Grade V. Most cases are Grade I and are managed conservatively.

What does grade 1 retrolisthesis mean?

The vertebra sits backward relative to the one beneath it, by 25% or less of the vertebral width. It is the mildest grade, usually degenerative, and frequently reported alongside disc height loss. On its own it is often an incidental finding rather than the explanation for someone’s pain.

Is retrolisthesis serious?

Usually not by itself, particularly at grade 1. It becomes clinically important if it is contributing to nerve compression or instability, which is a judgment your physician makes from your symptoms and examination rather than from the report alone.

What is the difference between retrolisthesis and spondylolisthesis?

Direction. Spondylolisthesis (also called anterolisthesis) is a forward slip; retrolisthesis is a backward one. Both are graded by the same percentage bands, though spondylolisthesis is the more studied of the two.

Can spondylolisthesis be reversed or corrected?

The slip itself does not move back. Non-surgical care aims at symptoms and function, not at restoring the vertebra’s position, and for most low-grade slips that is enough to live comfortably. Surgical stabilization is the only intervention that addresses the position, and it is reserved for specific indications.

Does spondylolisthesis get worse over time?

Often it stays stable, particularly degenerative low-grade slips in adults. Progression is more of a concern in children and adolescents with dysplastic or isthmic types, which is why those are monitored. Your physician can tell you whether yours warrants follow-up imaging.

Can I still exercise with spondylolisthesis?

Usually yes, and staying active generally helps, but which movements suit you depends on your type and grade. Isthmic slips in particular often tolerate extension poorly. Get specific guidance rather than following a general routine.

Where to Start

• If a report mentioned a slip and you have no symptoms — ask the physician who ordered the scan what it means for you. Incidental findings are common, and knowing that is usually the whole answer.
• If anything in the warning-signs list applies — particularly groin numbness or changes in bladder or bowel control — that is a medical matter now, not a posture one.
• If you have been graded, cleared to exercise, and the back pain keeps returning — a free 30-minute consultation includes a conversation and a whole-body postural assessment, in Boston, Newport or Los Angeles. Bring what your physician told you about limits.
• Not near a clinic? Virtual posture therapy works the same way, by video.

If you arrived worried by a word on a radiology report and are leaving with a clearer sense of what it does and does not mean, that is a reasonable result on its own.

Sources

• Margetis K, Gillis CC. Spondylolisthesis. In: StatPearls. StatPearls Publishing; updated 2025. Read the chapter
• Brinjikji W, Luetmer PH, Comstock B, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. American Journal of Neuroradiology. 2015;36(4):811–816. Read the review
• Wang YXJ, Káplár Z, Deng M, Leung JCS. Lumbar degenerative spondylolisthesis epidemiology: a systematic review with a focus on gender-specific and age-specific prevalence. Journal of Orthopaedic Translation. 2017;11:39–52. Read the review