What Is Spondylolisthesis? Grades, Symptoms, and Non-Surgical Treatment

Spondylolisthesis is a spinal condition in which one vertebra slips forward or backward relative to the vertebra below it, causing instability, pain, and sometimes nerve compression. It is graded on a scale of I through V based on the percentage of displacement. Grades I and II respond well to non-surgical spine treatment; higher grades require individualized evaluation.

Definition

The word “spondylolisthesis” comes from the Greek spondylos (vertebra) and olisthesis (slipping). When a vertebra shifts forward relative to the one beneath it, the condition is called anterolisthesis. When it shifts backward, it is called retrolisthesis. Both patterns disrupt the normal alignment of the spinal column and can narrow the spinal canal or intervertebral foramina — the bony openings through which nerve roots exit.

Spondylolisthesis is not a rare condition. Back pain affects 80% of people at some point in their lifetime, and vertebral slippage is among the structural findings most commonly identified on imaging for adults with persistent low back pain. Understanding the grade and type of slippage determines whether conservative care is appropriate — and for most patients with Grade I or II slippage, it is.

If you have been told you have spondylolisthesis and are wondering whether surgery is necessary, reviewing your options on our non-surgical spine treatment overview is a useful starting point. Nearly 1 in 5 patients told they need spine surgery choose not to have it — and for many, that decision is well-supported by evidence.

How Spondylolisthesis Develops

Vertebral slippage occurs when the structures that normally hold one vertebra in alignment with its neighbors are compromised. The two most common mechanisms are:

Isthmic Spondylolisthesis

This type results from a stress fracture or defect in the pars interarticularis — a small bridge of bone connecting the upper and lower facet joints on each side of a vertebra. The pars is vulnerable to repetitive hyperextension loading, which is why isthmic spondylolisthesis is particularly common in young athletes who perform gymnastics, wrestling, football lineman work, and weightlifting. Once the pars fractures bilaterally (a condition called spondylolysis), the vertebra loses its posterior anchor and can migrate forward over time.

Degenerative Spondylolisthesis

This is the most common type in adults over 50. As the intervertebral discs dehydrate and lose height, and as the facet joints develop arthritis, the posterior stabilizing structures weaken. The L4–L5 level is most frequently affected. Unlike isthmic spondylolisthesis, no fracture is present — the slip occurs because the entire functional spinal unit has lost its structural integrity through aging and wear.

Other Types

• Traumatic: Acute fracture of posterior elements from high-energy injury (rare)
• Pathologic: Bone weakened by tumor, infection, or metabolic disease allows slippage
• Iatrogenic: Can occur after spinal surgery when posterior stabilizing structures are disrupted

Why It Matters: Symptoms and Clinical Impact

The severity of symptoms correlates roughly — but not perfectly — with the degree of slippage. Some patients with Grade II slippage have significant pain and functional limitation; others with the same grade have minimal symptoms. What matters clinically is whether neural elements are involved.

Common Symptoms

• Axial low back pain: The most universal symptom — a deep, aching pain centered at the level of the slip, often worsened by standing, walking, or extension activities
• Hamstring tightness: A classic but underrecognized finding, especially in adolescents with isthmic spondylolisthesis; the body reflexively contracts the hamstrings to posteriorly tilt the pelvis and reduce shear forces at the slip level
• Radiculopathy: If the exiting nerve root is compressed by the slipped segment or an associated disc herniation, sharp pain, numbness, or tingling radiates down the leg in a dermatomal pattern
• Neurogenic claudication: In higher-grade slips with significant spinal canal narrowing, patients experience leg heaviness, cramping, or weakness with walking that is relieved by sitting or forward flexion — identical in presentation to spinal stenosis
• Gait abnormality: High-grade slippage (Grade III+) can produce a waddling or crouched gait due to significant pelvic tilt

For patients experiencing leg symptoms alongside back pain, our article on signs you can avoid spine surgery explains which clinical presentations tend to respond best to conservative care.

Key Components: Meyerding Classification

The Meyerding grading system measures what percentage of the vertebral body has shifted forward relative to the vertebra below. The slipped vertebra is divided into quarters, and the grade is assigned based on how far the posterior edge of the upper vertebra has migrated:

The grading system is measured on standing (weight-bearing) X-rays, which is important: the slip often increases in an upright position compared to lying down. MRI is used in addition to X-ray to assess whether the neural elements — the spinal cord, cauda equina, or nerve roots — are compressed at the slip level.

Non-Surgical Treatment for Spondylolisthesis

The clinical evidence strongly supports conservative management for Grade I and II spondylolisthesis. Even in higher-grade cases, non-surgical treatment serves as the appropriate first-line approach in the absence of progressive neurological deficit, bowel or bladder dysfunction, or severe deformity.

Physical Therapy: Core Stabilization

The cornerstone of non-surgical management is a structured physical therapy program focused on lumbar stabilization. The goal is not range-of-motion work or spinal extension exercises — those can worsen symptoms. Instead, the emphasis is on activating and strengthening the deep stabilizing muscles: the transversus abdominis, multifidus, and pelvic floor. Properly strengthened, these muscles reduce shear force at the slipped segment and allow patients to function with significantly less pain.

Activity Modification

Patients are advised to reduce or eliminate activities that load the spine in extension — such as contact sports, heavy lifting with lumbar extension, and high-impact activity — while the stabilization program progresses. This is not permanent restriction; as strength improves, activity levels are gradually restored.

Pain Management

Short-term use of NSAIDs, acetaminophen, or muscle relaxants addresses the inflammatory and spasm components of acute exacerbations. For patients with radiculopathy, epidural steroid injections provide targeted anti-inflammatory relief at the nerve root level, creating a window for physical therapy to progress.

Biologic Disc Repair

When the disc at the spondylolisthesis level shows significant annular disruption — common in isthmic cases where disc herniation accompanies the slip — intra-annular fibrin injection (annular tear repair) addresses the discogenic pain component directly. This biologic disc treatment targets the structural source of chemical pain sensitization in the disc rather than managing symptoms alone. Patients with Grade I–II slippage and a confirmed annular tear are candidates for fibrin disc treatment evaluation.

Bracing

In adolescents with active isthmic spondylolisthesis, rigid lumbosacral orthosis bracing reduces extension loading and is used during the initial healing phase. In adults, soft bracing provides proprioceptive feedback and reduces muscular guarding during the early phase of rehabilitation.

For a comprehensive comparison of evidence-based conservative interventions, see our non-surgical spine treatments ranked by evidence and our conservative spine care guide.

The Context for Surgical Discussion

When conservative care is insufficient and surgery is being considered, lumbar fusion is the most common surgical procedure for spondylolisthesis. Fusion eliminates motion at the slipped segment and corrects or stabilizes the slip. However, it is not a guaranteed outcome.

Roughly 40% of back surgeries do not achieve the patient’s desired outcome — a figure that reflects both patient selection challenges and the inherent limitations of addressing chronic pain through structural intervention alone. For patients with Grade I–II spondylolisthesis, the evidence does not favor early surgery over structured conservative care, which is why non-surgical management is the appropriate starting point for the vast majority of patients.

For patients who have been told fusion is their only option, reviewing spinal fusion alternatives provides evidence-based context for understanding what non-operative and minimally invasive options exist before committing to major surgery.

Related Terms

Spondylolysis

A stress fracture of the pars interarticularis without forward displacement. It is the precursor lesion in isthmic spondylolisthesis. Not all spondylolysis progresses to spondylolisthesis.

Anterolisthesis

Forward slippage of a vertebra relative to the one below. This is the predominant direction in both isthmic and degenerative spondylolisthesis.

Retrolisthesis

Backward slippage. More common at L5–S1 and in degenerative conditions. Often associated with significant disc height loss.

Spinal Stenosis

Narrowing of the spinal canal. Can coexist with or result from spondylolisthesis, particularly at higher grades, causing neurogenic claudication.

Spondyloptosis

Grade V spondylolisthesis in which the upper vertebra has completely displaced off the lower vertebra (greater than 100% slip). Rare and typically requires surgical reconstruction.

Common Misconceptions

“I need surgery because I have spondylolisthesis.”

Grade I and II spondylolisthesis — which represents the overwhelming majority of diagnosed cases — is managed non-surgically in most patients. Surgery is reserved for progressive neurological deficit, severe functional disability after exhausting conservative options, or high-grade structural instability. A diagnosis of spondylolisthesis alone does not indicate surgery.

“The slip will keep getting worse no matter what I do.”

Most low-grade slips are stable or slowly progressive. Appropriate core stabilization programs reduce shear loading at the slip level and prevent further displacement in the majority of Grade I–II cases. Progression to higher grades is not inevitable.

“Physical therapy will make it worse by moving the spine.”

Evidence-based lumbar stabilization therapy does not involve mobilization of the unstable segment. It focuses on building the muscular support system around the spine. Poorly designed exercise programs that include aggressive extension work can aggravate symptoms — which is why working with a therapist experienced in spine stabilization matters.

“Spondylolisthesis only happens to older people.”

Degenerative spondylolisthesis is most common in adults over 50, but isthmic spondylolisthesis affects adolescent athletes at high rates. In some collision sport populations, pars stress fractures are found in 10–15% of young athletes.

Patients who are uncertain whether they are a candidate for surgery or whether conservative options have truly been exhausted will find our article on signs you can avoid spine surgery and our guide to how to avoid spinal fusion surgery useful for making informed decisions.

Frequently Asked Questions

Can spondylolisthesis heal on its own without treatment?

Low-grade spondylolisthesis does not “heal” in the sense of the vertebra returning to its original position — the structural displacement is permanent once it occurs. However, symptoms resolve or significantly improve in most Grade I–II patients with appropriate conservative treatment, including core stabilization physical therapy and activity modification. The goal of non-surgical treatment is not reversal of the slip but stabilization of the segment and restoration of pain-free function. Many patients with Grade I spondylolisthesis have no symptoms at all and never require any treatment.

What is the difference between isthmic and degenerative spondylolisthesis, and does the type affect treatment?

Isthmic spondylolisthesis involves a fracture of the pars interarticularis and is most common in young athletes and adolescents; the slip occurs because the posterior bony arch is disrupted. Degenerative spondylolisthesis involves no fracture — it results from disc degeneration and facet arthritis causing the entire segment to lose stability, and it predominantly occurs in adults over 50. The type affects treatment in nuanced ways: isthmic cases in adolescents are managed with activity restriction and bracing during the active growth phase; in adults, both types are managed primarily with lumbar stabilization physical therapy. Degenerative spondylolisthesis at L4–L5 with associated stenosis is more likely to produce neurogenic claudication and is more likely to require decompression if conservative care fails.

Is spinal fusion the only surgical option for spondylolisthesis?

Lumbar fusion is the most commonly performed surgery for spondylolisthesis, as it directly addresses segmental instability by permanently joining two vertebrae. However, it is not the only option. For some patients with Grade III spondylolisthesis and significant canal narrowing but without severe instability, a decompression-only procedure (without fusion) is evaluated based on stability and neural compromise. The choice depends on the degree of instability, the patient’s age, bone quality, and the specific level affected. Importantly, roughly 40% of back surgeries do not achieve the patient’s desired outcome, which is why exhausting non-surgical care before committing to fusion is appropriate for most patients. Reviewing spinal fusion alternatives before scheduling surgery provides essential context.

How is spondylolisthesis diagnosed?

The primary diagnostic tool is a standing (weight-bearing) lateral X-ray of the lumbar spine. Upright imaging is essential because the slip often increases with gravity loading and may appear smaller or absent on supine imaging. The Meyerding grade is measured from this X-ray. MRI is then used to assess the soft tissue structures — the intervertebral discs, the spinal cord and nerve roots, and any associated disc herniation. CT scanning is occasionally used to better characterize bony anatomy. Flexion-extension X-rays are used to assess dynamic instability — whether the slip degree changes significantly with movement.

Can spondylolisthesis cause permanent nerve damage if left untreated?

In the vast majority of Grade I–II cases, spondylolisthesis does not cause permanent nerve damage when properly monitored and managed with conservative care. The risk of permanent neurological injury is primarily associated with high-grade slippage (Grade III and above) with significant spinal canal narrowing, or with acute neurological deterioration — loss of bladder or bowel control, progressive leg weakness, or rapidly worsening sensory deficits. These signs require urgent evaluation and are not appropriately managed with conservative care alone. Patients with Grade I–II spondylolisthesis who have stable symptoms and no progressive neurological signs do not face imminent risk of permanent nerve injury from the slip itself.

Sources & Further Reading

1. National Institute of Neurological Disorders and Stroke (NINDS). “Low Back Pain Fact Sheet.” U.S. Department of Health and Human Services. Available at: ninds.nih.gov
2. Kalichman L, Hunter DJ. “Diagnosis and conservative management of degenerative lumbar spondylolisthesis.” European Spine Journal. 2008;17(3):327–335.
3. Bydon M, et al. “The Role of Spondylolysis and Spondylolisthesis in Lumbar Spine Pathology.” Spine Journal. 2016.
4. Weinstein JN, et al. “Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis.” New England Journal of Medicine. 2007;356(22):2257–2270. (SPORT Trial)
5. Pearson AM, et al. “Predominance of nonoperative treatment of degenerative spondylolisthesis through 4 years: results from the SPORT trial.” Spine. 2011.
6. Fredrickson BE, et al. “The natural history of spondylolysis and spondylolisthesis.” Journal of Bone and Joint Surgery. 1984;66(5):699–707.
7. Försth P, et al. “A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis.” New England Journal of Medicine. 2016;374(15):1413–1423.

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