Abstract
BACKGROUND: The healthy nucleus pulposus (NP) of the intervertebral disc is normally replete with proteoglycans and highly hydrated. With degeneration, the disc loses its capacity to bind water, substantially reducing its ability to cushion physiologic loads. Supplementation of degenerated NP with a commercially available NP allograft represents a promising approach to ameliorating lumbar discogenic pain. METHODS: This was a prospective, single arm clinical study involving 21 patients at 5 US sites. The magnitude of improvement in back pain severity, back disability and quality of life was evaluated in Medicare-age (≥65 years) patients with chronic axial low back pain treated with intradiscally delivered NP allograft at up to three lumbar vertebral levels (L1-S1). Followup was at 1, 3 and 6 months. Back pain was determined using an 11-point numeric rating scale (NRS), back function by Oswestry disability index (ODI) and quality of life using the PROMIS-29 questionnaire. RESULTS: There was a 60% reduction in average back pain scores between baseline and 6 months; the difference (4.0, 95% CI [2.9, 5.2]) was statistically significant (p < 0.001). 82% and 71% of participants achieved ≥30% and ≥50% NRS improvement, respectively, at 6 months, and 65% of participants reported a final NRS score ≤3. The 6-month improvement in mean ODI scores was 50% with an average difference of 22.8 (95% CI [14, 31]) (p < 0.001). 68% and 51% realized ≥30% and ≥50% ODI improvements, respectively, at 6 months. All PROMIS-29 domains showed improvements toward the normative mean value of 50 by 6 months. No adverse events related to the NP allograft were reported. CONCLUSION: These findings show clinically significant pain palliation, functional improvement and quality of life enhancement in older adults following supplementation of the degenerated disc with NP allograft.