Feasibility and Safety of Treatment of Painful Lumbar Degenerative Disc Disease with an Injectable Hydrogel Implant at One-year Follow-up.
Bibliographic record
Abstract
BACKGROUND: Degenerative disc disease (DDD) is the most common cause of chronic low back pain (CLBP). In DDD, proteoglycans within the nucleus pulposus break down and lose their ability to retain water, thereby reducing the volume of intervertebral discs and decreasing their weight-bearing capacity. Mechanical loading shifts to the annulus fibrosus, creating fissures and tears that leak crucial factors in the pain to cascade into the intradiscal space and trigger inflammation. When conventional treatments for CLBP fail, surgical options may be required. These surgeries carry risks and require months to heal. For intervertebral discs requiring augmentation, an implant in the form of an injectable, polymer-based hydrogel was developed for the percutaneous treatment of CLBP secondary to lumbar DDD. We hypothesize that the implant's hydrophilic properties will increase water retention and hydration, improve biomechanics, distribute axial loading more evenly across the annulus fibrosus, and reduce some mechanical sources of discogenic disc pain. OBJECTIVE: To evaluate the safety and efficacy of a novel, injectable hydrogel implant for the treatment of CLBP. STUDY DESIGN: Prospective, single-arm, multicenter feasibility and safety study. METHODS: Patients with CLBP lasting for longer than 6 months, DDD (modified Pfirrmann grades 4-8), competent outer annuli, numeric rating scale (NRS) scores >= 4, and Oswestry Disability Index (ODI) scores >= 30 were enrolled in 3 outpatient clinics in Canada and Colombia. The hydrogel implant, melted and equilibrated to 65°C, was injected intradiscally with a 17G needle under local anesthesia, using fluoroscopic guidance. The hydrogel cooled to approximately 42°C as it exited the needle directly into the nucleus. Patients were discharged that day. Clinical assessments included ODI and NRS (taken at one, 3, 6, and 12 months), radiographs, computed tomography, and magnetic resonance imaging (MRI) scans. The primary outcome was the successful insertion of the implant in a lumbar disc nucleus. RESULTS: Sixty patients (36 women, 24 men), 49.0 ± 9.3 years old, received 83 implants (one disc-level: n = 37; 2 disc-levels: n = 23). All patients were implanted successfully without complications during the procedure or at discharge. One patient died (for reasons unrelated to the device/procedure), and one patient was lost to follow-up, for n = 58 at the 12-month follow-up. Five patients (8.6%) experienced increased low back pain (LBP) or leg pain and/or leg paresthesia, due to what radiological procedures confirmed was partial implant migration. Migrated implant portions were removed endoscopically from those patients 2 weeks to 10 months after implantation, constituting a 6% (5/83) failure rate. Mean (standard error [SE]) ODI scores in the patients was 9.6 (1.7) at the final follow-up. In the full cohort, ODI scores improved from the baseline mean (SE) of 57.4 (1.5) to 12.7 (1.8) at one month and 11.2 (2.0) at 12 months (P < 0.001). NRS back pain scores improved from the baseline of 7.3 (0.2) to 2.2 (0.3) at one month and 2.1 (0.3) at 12 months (P < 0.001). NRS leg pain scores improved from the baseline of 5.5 (0.4) to 1.1 (0.2) at one month and 1.4 (0.3) at 12 months (P < 0.001). The number of disc levels treated was not correlated with outcomes. LIMITATIONS: As was inherent to a feasibility and safety study, limitations included a relatively small patient cohort and lack of a control group. CONCLUSION: A novel, injectable, polymer-based hydrogel implant was successfully inserted in 83 of the intervertebral discs of 60 patients for the effective treatment of CLBP secondary to DDD. Clinically significant improvements in function, LBP, and low leg pain were maintained through 12 months.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".