Your MRI report says that you have a herniated disc in your lumbar spine. This sounds scary and could be the source of your back and/or leg pain. Here is what you need to know and what your doctor should be telling you.
Your lumbar spine consists of five vertebrae (L1-5) and ends at your sacrum. The vertebrae are bony blocks that surround and protect your spinal cord and nerve roots within the spinal canal. The vertebrae have musculotendinous and ligament attachments that aide in strength, support, and flexibility.
Your lumbar discs are located between the lumbar vertebrae from L1 to the upper portion of your sacrum (S1). The intervertebral discs are the shock-absorbers between the bony block vertebrae. The roles of the disc are to absorb and distribute forces during movement and loading of the spine. There are two main components to your lumbar disc: a thick circular exterior layer (annulus fibrosus) and a soft, gel-like center (nucleus pulposus). The sinovertebral nerves are nerves that come off of each spinal nerve root and provide sensory innervation to the intervertebral discs. Of the symptomatic lumbar disc herniations, 95% occur at the bottom two levels of the lumbar spine: L4-5 and L5-S1.
When we are born, the disc is comprised of about 80% water, which gives it its spongy quality and allows it to function as a shock absorber. As we age, the water content decreases and the disc becomes less capable of acting as a shock absorber.
Through a traumatic injury or degenerative changes that occur with aging, the outer annulus fibrosus can weaken and develop cracks or fissures, and in some cases, cause the inner nucleus pulposus to leak out or “herniate.” This process may occur in stages, as is often the case for degenerative changes, or all at once, which is the case for some traumatic injuries to the disc. It is important to understand that a true disc herniation is different from a diffuse disc bulge.
The nucleus pulposus contains chemicals that are highly irritating to spinal nerve roots and can be a source of intense back and/or leg pain. In addition to back pain, some patients may develop numbness or tingling in their legs. Occasionally, leg weakness may also occur. In rare cases, saddle anesthesia and bowel or bladder dysfunction (retention or incontinence) may occur in a condition called cauda equina syndrome. This is a spinal emergency and should prompt the patient to seek immediate medical attention.
Most acute disc herniations can be treated successfully by non-surgical means. Your doctor may prescribe a very short period of rest and decreased activity along with some medication for symptomatic relief. These medications can include anti-inflammatory medications, muscle relaxants, a short course of oral steroids, or neuropathic pain medication. Physical therapy and/or epidural steroid injections are commonly used treatment modalities, as are some alternative therapies such as chiropractic care or acupuncture.
The natural history of a lumbar disc herniation is favorable and most patients with a lumbar disc herniation will not require surgery. Ninety percent of patients treated conservatively will have significant improvement or complete resolution of their symptoms by six weeks. For the patients who fail to respond to these conservative measures, surgery has been shown to be beneficial in numerous studies. The six-month period from symptom onset seems to be a critical time point where post-operative recovery may be compromised. Although patients who undergo surgery at a later time point may fail to receive the same level of postoperative results as those undergoing earlier intervention, most studies support that lumbar discectomy provides benefit regardless of the time point at which it is performed.
The goal of surgery is to relieve the pressure on the pinched nerve by removing a small portion of the bone that overlies the nerve and remove the part of the disc and loose fragments that are compressing the nerve. This can be accomplished through a traditional open approach or through minimally invasive approaches that utilize a microscope, a tubular retractor, or an endoscope. Long-term outcomes after a lumbar discectomy are similar regardless of the technique that is used.
To reduce the risk of repeat herniation, you may be prohibited from bending, lifting, and twisting for the first few weeks after surgery. With both surgical and nonsurgical treatment, there is a small chance that the disk will herniate again. Most patients are able to resume their normal activities after a period of recovery following surgery. Your doctor will be able to talk with you about the advantages and disadvantages of both surgical and nonsurgical treatment of lumbar disc herniation.