Question: What level does a disc need to herniate to require surgery?

I know that on an MRI scan, the amount of disc herniation (L5 in my case) is measured in increments of millimeters (mm). Are there studies, opinions or facts that indicate which level (# of mm) of disc herniation warrants which treatment?

For example:
?mm-?mm has success with medication and non-use
?mm-?mm has success with epidural injections
?mm-?mm requires surgery

If a lumbar disc herniated to a certain level, does low back surgery become necessary, bypassing any conservative treatments?

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Doctor’s response: Only clinically significant if it affects a nerve root

There is no particular mm measurement for a lumbar herniated disc that would indicate the best treatment. Instead, physicians determine the best course of treatment by looking at the patient’s clinical situation, including factors such as the amount of pain a patient has, the amount of disability, and the duration of the patient’s symptoms.

A disc herniation or bulge is usually only clinically significant if it is pinching a nerve root. It matters more where the disc is herniated (e.g. midline disc herniation rarely pinches a nerve root) and how big the person’s spinal canal is. If the canal is small, even a small disc herniation may pinch a nerve root. If the canal is large, even a sizable disc herniation may not cause any symptoms.

For leg pain due to a pinched nerve root from a lumbar herniated disc generally 6-12 weeks of conservative treatment is advisable (NSAIDs, narcotic pain medications, physical therapy, chiropractics, or epidural injections). If this fails, or the patient is in extreme pain, then surgery may be a better option to speed the recovery.

If the patient’s primary problem is back pain, it matters much more what the disc space itself looks like and rather than the amount of disc herniation. If there is a lot of wear in the cartilage and collapse of the disc space, and the patient has not found pain relief or improved function after about six to twelve weeks of aggressive non-surgical treatment, then a spinal fusion may be reasonable.

Finally, it’s important to remember that what works well for one patient with a symptomatic herniated disc may not work well for another, and patients should work with a spine specialist to determine the appropriate course of surgical and non-surgical treatments for their particular situation.

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In Spine-health’s Doctor Advice section, physicians respond to frequently asked questions about back pain issues. These responses represent the opinion of one physician, and do not necessarily reflect the views of the broader medical community. The advice presented has not been peer reviewed by Spine-health’s medical advisory board.