Introduction
Receiving the results of a spinal MRI can be a confusing and anxiety-inducing experience. The report, filled with technical terms, may mention an unfamiliar finding: “Schmorl’s nodes.” While the name sounds intimidating, Schmorl’s nodes are an incredibly common finding on spinal imaging and are, in the vast majority of cases, a harmless, incidental discovery.[1]
For many people seeking an answer to their chronic back pain, it is tempting to latch onto an abnormal finding as the definitive cause. However, a Schmorl’s node is to a spinal radiologist what a wrinkle is to a dermatologist; a sign of wear and tear or a past event, not a sign of an active, painful disease.
This guide will explain Schmorl’s nodes and explain the distinction between a benign MRI finding and a true cause of back pain.
What is a Schmorl’s Node?
A Schmorl’s node is a protrusion of the soft, gel-like inner material of the intervertebral disc (the nucleus pulposus) through the endplate (the top or bottom surface of the vertebral bone) and into the bone of the vertebra above or below it.[2]
Think of an intervertebral disc as a jelly donut. The tough, fibrous outer ring is the “crust” of the donut, and the soft, jelly-like inner material is the “jelly.” A Schmorl’s node occurs when a bit of that “jelly” is squeezed so hard that it pokes a hole through the vertebral “crust” and into the bone. [1]
These nodes are almost always discovered incidentally on an MRI or CT scan of the spine, which is often ordered for an unrelated reason, such as back pain from a muscle strain or a nerve impingement from a herniated disc.
The Two Reasons They Are So Common
Schmorl’s nodes are prevalent for two main reasons: their common causes and the sensitivity of modern medical imaging.
- Their Causes: The formation of a Schmorl’s node can be attributed to several factors, all of which are common in the general population:
- Developmental Weakness: Some individuals may have a congenital or developmental weakness in the endplates of their vertebrae, making them more susceptible to the nodes’ formation.3
- Trauma: A sudden, forceful compression of the spine—such as from a heavy fall, a car accident, or even a strenuous activity like lifting a heavy object incorrectly—can cause an acute node to form. [2]
- Chronic Degeneration: Over time, as the intervertebral discs and the vertebral endplates naturally weaken with age, the risk of a Schmorl’s node forming increases. They are a common sign of a degenerating spine, much like grey hair is a sign of aging. [3]
- The Sensitivity of MRI: A standard X-ray often cannot see a Schmorl’s node. However, an MRI scan provides a highly detailed, high-resolution view of the spine’s soft tissues and bony structures.5 The incredible sensitivity of the MRI means that it can detect these small protrusions that would have been completely missed in the past. [4] As a result, radiologists now find them in a large portion of the population, with some studies estimating a prevalence of 38% to 75% of individuals.
Symptomatic vs. Asymptomatic
This is the most important part of understanding your diagnosis. The vast majority of Schmorl’s nodes are asymptomatic, meaning they do not cause any pain. A chronic, old Schmorl’s node is a stable finding—the bone and disc have healed around it, and it is not a source of active inflammation or pain.
However, in very rare cases, a Schmorl’s node can be the direct cause of a person’s back pain.[6] This occurs when the node is acute and has formed as the result of a recent traumatic event. A radiologist can differentiate an acute, symptomatic node from a chronic, harmless one by looking for a specific signal on the MRI. An acute node will show signs of bone marrow edema—a bright, white signal on a T2-weighted MRI sequence that indicates active inflammation and fluid in the bone marrow surrounding the node.[7] A chronic node will not have this inflammatory signal. [5]
A doctor will correlate the MRI finding with the patient’s clinical history. If a patient comes in with a history of a sudden, sharp, acute back pain after a specific traumatic event and their MRI shows a new, inflammatory Schmorl’s node, the node is likely the cause of the pain. However, if a patient has chronic, ongoing back pain and the MRI shows an old, non-inflammatory Schmorl’s node, the node is almost certainly an incidental finding, and the doctor will look for a more likely cause of the pain, such as:
- A herniated or bulging disc
- Facet joint arthritis
- Spinal stenosis
- Muscle strain or ligament sprain. [6]
What to Do About It
If your MRI report mentions Schmorl’s nodes, here is what you should do:
- Consult with Your Doctor: Do not panic or assume the worst. The first step is to have a thorough discussion with your doctor or an orthopedic specialist. They will be able to interpret the MRI findings in the context of your specific symptoms and medical history.
- Focus on the Real Cause: Trust your doctor’s judgment. If the MRI shows a common, chronic Schmorl’s node and a more common cause of back pain, focus your treatment on the more likely cause.
- Management for Acute Nodes: If a rare, acute, and painful Schmorl’s node is diagnosed, the treatment is typically conservative and focuses on reducing inflammation.[8] This may include a period of rest, physical therapy, and anti-inflammatory medications.
- Embrace It as an Incidental Finding: For most people, a Schmorl’s node is simply a part of their spinal anatomy. It does not mean back pain is inevitable or that the spine is inherently weak. It is simply a sign of a past event.
