The Larger The Disc Injury The More Likely To Heal Without Surgery

Picture from article referenced below

I saw a few patients with slipped discs this past week. Most patients are still very fearful even if their 'slipped discs' happened years ago. They will complain that they have been having back problems ever since.

Having written previously about how 'slipped discs' can heal I will share with my patients the facts about how the larger the disc injury, the more likely it can heal without surgery.

The picture above shows the diffferent types of herniated disc, bulging being the mildest and sequestration the most severe.

When there is a lumbar disc herniation, there is a tear or damage to the outer layers (annulus fibrosus) leading to leakage (or herniation) of the soft, gel-like inside material (nucleus pulposus). This leakage may touch or compress (irritate) the spinal nerves which causes an inflammatory response. This results in the patient complaining of pain, sensations of numbness, tingling sensations down their leg and sometimes neurological dysfunction.

Conservative management for 6 weeks (instead of surgical management) is usually the first choice for  newly diagnosed patients. In some patients, spontaneous reabsorption of the disc herniation is a widely recognized clinical observation. The spontaneous shrinkage or disapperance of a herniated lumbar intervertebral disc without surgery is called reabsorption or resorption.

The biological mechanisms involved in herniated disc resorption includes macrophage infiltration, matrix remodelling and neovascularization.

Since our immune system recognizes the gel leakage as 'foreigners' in our vertebral epidural space, this triggers a casade of inflammatory responses including phagocytosis of inflammatory cells, enzymatic degradation, increased inflammatory mediators. All of which means that healing is taking place. As the herniation decreases after resorption, the clinical symptoms also improve.

The type and composition of the herniated disc may predict the possibility of natural resorption. Extrusion and sequestration have a higher chance for resorption since the leakage is in the epidural space, creating favorable conditions for macrophage infiltration and neovascularization.

Picture from Radiopaedia

However if the area of the spine shows Modic changes, it is not conducive to macrophage infiltration and ingrowth of blood vessels, thus preventing resorption. Modic changes in the spine occur in response to degenerative changes of the discs, pathology or infections. 

An earlier meta-analysis of 38 clinical studies done in 2015 showed that resorption of lumbar disc herniation was as high as 62-66 percent (Chiu et al, 2015).

Further research is ongoing to understand what conditions can induce or promote the reabsorbtion of 'slipped discs'. This will help clinicians to rationally formulate treatment plans for patients.

Today is exactly one year on from my 2nd bike accident. Not the kind of anniversary I like to remember but it does mean that I've come quite a bit further than where I was. Of course I'm still not working the hours I did before the accident, but definitely much more than just after the accident. So I'm testimony that you can definitely recover, even after 2 compression fractures in my spine! 

References

Chiu CC, Chuang TV, Chang KH et al (2015). The Probability Of Spontaneous Regression Of Lumbar Herniated Disc: A Systematic Review. Clic Rehabil. 29(2): 184-195. DOI:10.118/269215514540919.

Yu P, Mao F, Chen J et al (2022). Characteristics And Mechanisms Of Resorption In Lumbar Disc Herniation. Arthritis Res Ther. 24, 205. DOI: 10.1186/s13075-022-02894-8

A meta-analysis of 38 clinical studies done in 2015 showed that resorption of lumbar disc herniation was as high as 62-66 percent.