Injectable gel shows potential for relief among those with chronic low back pain

The preliminary results from an experimental hydrogel injected into degenerated spinal discs are raising the prospect of a potential new treatment for the scourge of low back pain.

Degenerative disc disease is the leading cause of chronic low back pain and occurs due to the accumulation of damage to the intervertebral discs that cushion the spine.

Healthy discs absorb and distribute forces to facilitate movement and flexibility in the spine, however, with cumulative damage they can become dry, thin, cracked, or torn, which causes pain or loss of motion.

This damage happens with normal ageing – by 60 most people have at least some disc degeneration – but low back pain caused by disc degeneration can also start early in life (before the age of 20).

Now, in a small study of 20 participant, researchers have found an experimental formulation of a hydrogel – a polymer network that can hold large amounts of water – injected into discs can reduce low back pain and improve physical function.

These findings hold promise for a future interventional treatment of patients unable to find relief from conservative care (which includes rest, analgesics, physical therapy, back braces, and epidural steroid injections to manage or reduce pain) and before resorting to surgical intervention.

“We really have no good treatments for degenerative disc disease, aside from conservative care,” says lead author Douglas P. Beall, chief of radiology services at Clinical Radiology of Oklahoma in the US.

“Surgery is statistically no more effective than conservative care and can potentially make things worse; nerve ablation is appropriate for only a few patients; and existing hydrogels are inserted through an incision as a soft solid, which can pop out of place if you’re not highly skilled in placing it.

“Because this gel is injectable, it requires no incision and it augments the whole disc, restoring its structural integrity, which nothing we have currently can do.”

A potential chronic low back pain treatment

The small study consisted of patients aged 22 to 69 who had chronic degenerative disc disease low back pain. Each had described their pain as four or higher on the 10-point pain scale but had previously only experienced mild relief from conservative care.

Patients were sedated for the procedure, which involved heating the gel until it became a thick liquid and using a 17-gauge needle to inject it directly into the affected discs.

This injection was guided by fluoroscopy, a type of medical imaging that shows a continuous X-ray image on a monitor (like a movie) and is used to study moving body structures.

Once injected into the affected disc, the gel filled in the cracks and tears, adhered to the disc’s centre and outer layer, and solidified.

After six months, patients’ average self-reported pain reduced from a 7.1 down to 2.0 (on a scale of zero to 10), and average scores fell from 48 to 6 on a questionnaire used to gauge the impact of low back pain in preventing patients from performing normal activities.

“If these findings are confirmed in further research, this procedure may be a very promising treatment for chronic low back pain in those who’ve found insufficient relief from conservative care,” says Beall. “The gel is easy to administer, requires no open surgery and is an easy procedure for the patient.”

The gel used in this study, Hydrafil™, is a second-generation hydrogel developed by ReGelTec, Inc for which Beall is a medical adviser to.

The research will be presented at the Society of Interventional Radiology Annual Scientific Meeting, held from 11-16 June 2022 in the US.