Endplate Injury

The endplate is the most vulnerable part of the disc.

Only one millimeter wide—the tip of a sewing needle—the endplate is a sheet of cartilage and bone that covers the top and bottom of each disc. Unlike the rest of the disc, the endplate is rich in nerve endings.

The significance of these nerve endings is, when damaged, the endplate will generate pain. Any force that can produces a disc bulge—including overload and excessive bending—can damage the endplate.

Can you describe a typical case?

Annie, age 65, rode her horse at full gallop. With her iPhone in hand, she twisted to snap a picture of her grandchildren who were riding behind her. Suddenly, her horse took a misstep and jolted her as she was still twisted. By that evening, Annie felt a persistent ache over her back which would not go away in the months ahead. The vibration of an uneven road, the impact of walking, and bending her spine aggravated the ache. When Annie told the doctor that the pain affected her back, he dismissed her: “If there’s no sciatica, there’s not much I can do for you.”

What does an endplate injury look like on an MRI?

Endplate fractures appear as an irregular jagged appearance on the MRI. When there is massive inflammation, the neighboring vertebral body becomes bright from swelling. On your radiographic report, this signal is called a Modic change.

Schmorl’s nodes are vertical disc extrusions. The nucleus inside the disc can leak outward into the vertebral body. Modic changes might also be present.

Keep in mind, however, that most endplate injuries are undetectable to MRIs.

How does an endplate injury occur?

The endplate is the weakest part of the disc. Due to this structural vulnerability, the endplate is the most likely structure to fail under compression. For Annie, this compression occurred with a sudden jolt from her galloping horse. For many, the injury is cumulative exposure to smaller jolts such as the vibration from operating heavy machinery. Excessive lifting and bending, particularly flexion, compresses the disc and pressurizes the endplates beyond their physical limits.

What is the injury mechanism for the endplate?

Though delicate, the endplates are integral to the structure of the disc. A torn endplate causes a pressure leak of the disc, which predisposes it to wearing down. These long-term degenerative effects may include a disc bulge,  loss of disc height, and drying out of the nucleus.

The endplates are an important source of disc pain. Unlike the annulus wall and nucleus gel—which lack nerve endings—the endplate is sensitive and a pain generator when damaged.

Endplates injuries are slow to heal. They are associated with persistent pain, usually achy in nature, which may persist beyond half a year. After an endplate injury, the compromised disc can develop other injury mechanisms such as sciatica from a disc bulge and instability.

What are examples of endplate injury?

 

• • Sudden Jolts

     

    • • Falls
    • • Misstep off a curb
    • • Sporting injuries

• • Repetitive Bending

     

    • • Sit-ups and crunches
    • • Lifting objects off the floor

• • Bending Under High Load

     

    • • “Butt wink” at the bottom of a squat
    • • Loss of form on a leg press machine

• • Vibrational exposures

     

    • • Farm machinery
    • • Military vehicles
    • • Trucks
    • • Aircraft
    • • Jack-hammer operator

How does an endplate injury feel?

An endplate injury, reflecting inflammatory damage, feels sharp at first followed by an aching bone sensation. One hallmark of an endplate injury is a persistent type of pain that is hard to escape—in contrast to disc bulges which have a more intermittent character. Unless additional mechanisms are involved, there is usually no sciatica with an isolated endplate injury. The location of pain is toward the center of the back. Bending, particularly flexion, increases pain due to increased compression onto the sensitized endplate.

What are risk factors for endplate damage?

 

• • Disc Height Loss

If a prior injury leads to the a loss in disc height, the endplates will experience increased compressive forces.

 

• • Osteoporosis

Osteoporosis may weaken all bone in the body, including the bone of the endplates. In addition to the vertebral body, which is at increased risk of fracture, so too is the endplate, which becomes more fragile and therefore more easily fractured from osteoporosis.

What are different types of endplate injury?

Endplate Fracture

An endplate fracture is a tearing of the cartilage and bone located on the top and bottom of each disc. Inflammation arises from the local injury to the tissues and from the immune-stimulating properties of the exposed nucleus gel within. The endplate fracture is observed on the MRI as an irregular curved shape around the vertebra-disc connection and as Modic changes—bright spots in the vertebral body.

Schmorl’s Nodes

A Schmorl’s node is a vertical migration of the nucleus gel into the vertebral body adjacent to it. Since the nucleus is inflammatory outside of the confines of the disc, nucleus extrusion inflames the adjacent bone and triggers Modic changes.

Vertebral Body Fracture

Extreme compression will, in addition to endplate injury, fracture the vertebral body. A wedge compression crushes down the vertebra. In a healthy spine, the vertebral body fractures only under high-force events such as a fall. An exception is any process that weakens the bone. Osteoporosis predisposes the vertebral body to weakness and fracture under everyday stresses such as a cough.

What are common misunderstandings?

 

• • Overlooking the Injury

Since endplate fractures are common and sometimes not painful, doctors make the mistake of assuming all endplate fractures must be likewise pain-free.

 

• • Misdiagnosis

Spine conditions that don’t cause sciatica are often diagnosed into vague diagnostic categories: non-specific low back pain, degenerative disc disease, and psychosomatic categories. Misdiagnosis is more likely with an endplate fracture because most of them are invisible to the MRI.

 

• • Assuming the injury will heal quickly

Endplate injuries heal at their own pace, as they require inflammation in the vertebral body and cartilage to settle down. This process may take six months to a year.

 

• • Failure to avoid flexion and side bending

Endplates can occur anywhere along the endplate. Most typically, however, they occur at the front of the vertebral body or the side of the vertebral body. Bends toward the direction of the endplate fracture aggravates the weakened tissues.

 

• • Overtraining the Injury

Aside from bending stresses, the endplate is compression intolerant. Lifting heavy weights and activities that jostle the spine—running, hiking on uneven ground, and plyometrics—will increase the inflammatory cascade, setting your healing back.

What are typical pain-triggers to be avoided?

 

• • Bending toward the direction of the endplate fracture

Bending toward and holding the bend in the direction of the endplate fracture tends to ramp up the pain.

 

• • Carrying heavy loads

Endplates are the weakest structure of the disc and the compression of carrying heavy loads will irritate the endplates most.

 

• • Jolting activities

Jolting, a form of pulsatile compression, is uniquely irritating to the endplates, which are designed to transfer the stresses to the adjacent vertebral body. Running and jumping are not your friend.

 

• • Vibrational exposures

Work that requires exposure to jack hammers and rickety machinery should be avoided.

What are relieving and therapeutic factors?

 

• • Posture

The best posture is a neutral posture or a mildly extended posture, which offloads the front of the endplate, which is the main location for endplate fractures. 

 

• • Position of Respite: This position takes away most compression and subtly extends the hips and spine, thereby taking you away from the two main pain-triggers.

• • Mechanical Variety

Like disc bulges, endplate fractures hates stasis—long commutes, sitting in an office all day, and standing in line are common aggravators. 

 

• • Walking

Walking is relieving because of the mechanical variety and the gentle massaging effect on the disc. Walk with a tall upright posture and allow the arms to swing freely. Walk briskly but without striding out your legs too far, as this may stretch your sciatic nerve.

 

• • Traction based Therapy

Gentle traction can offload the endplate injury. Traction is best performed under the guidance of a skilled physical therapist or chiropractor. While the temptation to do-it-yourself is great, simply hanging upside down on an inversion table or hanging from a bar is simply too forceful. In doing so you are increasing your changes of traction-injuries, such as annulus tears and instability. More than 70% disc height and a larger size disc bulge make traction more effective.

 

• • Stability Exercises

Practicing stability exercises such as the McGill Big 3 will enhance your muscular endurance. This stiffness will help you retain the good posture needed to heal from this mechanism.

What are healing mechanisms for an endplate fractures?

Given the right mechanical conditions, endplate fractures gradually wind down in inflammation and in pain. This process can be tracked by your improvement and by MRI, which shows a progressive process of healing by the different type of Modic changes observed:

 

• • Modic 1: The new injury shows inflammation and edema.

• • Modic 2: The healing injury shows fatty infiltration into the injured area, an early healing mechanism.

• • Modic 3: The endplate develops sclerotic change and endplate thickening, reflecting a calcification and gristling process which indicates completion of the healing process.

When should I consider surgery?

There are no effective surgical options for an endplate fracture or a Schmorl’s node.

A vertebral fracture may benefit from a vertebroplasty, a procedure that injects cement into the collapsed vertebral body.

A kyphoplasty is a similar procedure which starts with the use of an inflatable balloon to clear a space for the cement to be added. Both procedures reduce pain related to vertebral body fractures and help maintain disc height. The risks of the procedure involve leakage of the cement leading to nerve damage and blood clots. The blood clots may cause pulmonary embolus—blood clotting to the lungs, which may be fatal.

Selected References

Wang, Yue, Tapio Videman, and Michele C. Battié. “Lumbar vertebral endplate lesions: prevalence, classification, and association with age.” Spine, 2012.

Modic, Michael T., et al. “Degenerative disk disease: assessment of changes in vertebral body marrow with MR imaging.” Radiology, 1998.

McGill, Stuart. Low back disorders: evidence-based prevention and rehabilitation. Human Kinetics, 2015.

McGill, Stuart M., and Jacek Cholewicki. “Biomechanical basis for stability: an explanation to enhance clinical utility.” Journal of Orthopaedic & Sports Physical Therapy 31.2 (2001): 96-100.

Adams, Michael A., Manos Stefanakis, and Patricia Dolan. “Healing of a painful intervertebral disc should not be confused with reversing disc degeneration: implications for physical therapies for discogenic back pain.” Clinical biomechanics 25.10 (2010): 961-971.

Jim, Lysander. Specific Spine: A Doctor’s Guide to a Healthy Back. M.D. Muse Media, 2023.