Hydrogel Augmentation of the Lumbar Intervertebral Disc: An Early Feasibility Study of a Treatment for Discogenic Low Back Pain

Abstract

Purpose

To assess the safety and effectiveness of intradiscal hydrogel in patients with chronic low back pain (CLBP) due to degenerative disc disease (DDD) refractory to conventional medical management.

Materials and Methods

Twenty patients aged 22–69 years with numerical rating scale (NRS) pain of ≥4 were enrolled. All patients with CLBP resulting from DDD confirmed by imaging and discography received injections of hydrogel (Hydrafil Intervertebral Disc Augmentation; ReGelTec, Baltimore, Maryland) at 1 or 2 lumbar levels (29 levels treated) from August to December 2020. The primary safety end point was freedom from serious adverse events (SAEs). The primary performance end point was successful gel delivery into the desired disc. Patients were also assessed on the NRS as well as the Oswestry disability index (ODI).

Results

Nineteen patients were followed up at a mean of 131 days, and 1 patient was lost to follow-up. Preliminary results showed significant reductions in median NRS back pain from 7 (range 4–10) to 1 (range 0–8) (P <.0001) and median ODI scores from 54 (range 22–58) to 2 (range 0–58) (P <.0001) at 6 months of follow-up. There were 5 SAEs, and 4 of the 2 were determined to be associated with treatment.

Conclusions

This early feasibility study showed that the hydrogel implant was safe with no persistently symptomatic SAEs, and demonstrated effectiveness with significant reduction in pain and improvement in function when used to treat painful DDD and CLBP.