Chronic Back Pain

New study – Effectiveness of epidural amniotic fluid injection for low back pain

A study was recently completed on the use of epidural amniotic fluid for lower back pain. Dr. Matthew Thorsen was involved in the study, which was published in The Spine Journal Volume 20, Issue 9, Supplement, September 2020, Page S82

The study concluded that AF epidural injections are most effective for patients with lumbar HNP and moderately effective for those with stenosis. AF injections for DDD patients gave inconsistent results. See below for complete details or click here.

BACKGROUND CONTEXT

Epidural corticosteroid injections have long been used to treat pain and inflammation associated with lumbar HNP, DDD and spinal stenosis symptoms. amniotic fluid, AF, is rich in the components that are believed to contribute to healing by minimizing inflammation. AF injections in nonspinal conditions have been shown to be safe and avoid adverse effects related to steroids.

PURPOSE

To investigate the efficacy and safety of a single amniotic fluid injection into the epidural space for the treatment of low back pain. Specifically, this pilot study is to define indications for future large-scale comparative studies. Three diagnostic LBP patient groups were evaluated, HNP, stenosis, and DDD.

STUDY DESIGN/SETTING

IRB approved prospective three cohort clinical study.

PATIENT SAMPLE

Patients were enrolled who had LBP and leg symptoms for more than 3 months with clinical and MRI findings for HNP, stenosis or DDD. Inclusion criteria necessitated that patients had not responded to medications, physical therapy, and chiropractic.

OUTCOME MEASURES

Back pain and leg pain VAS, ODI, PROMIS, pain medication usage.

METHODS

After obtaining consent, 20 patients in each diagnostic group, had 2mls transforaminal epidural AF injected at symptomatic level using fluoroscopy. Pre- and postprocedure outcomes were obtained with follow-up outcomes obtained at 2 weeks, 6 weeks, 3-4 months, 6 months and 1 year.

RESULTS

The average age (± SD) of HNP, stenosis, and DDD patients was 39±13, 57±10, 44±14 respectively. There were no complications or other adverse effects. HNP patients had the greatest reduction in symptoms with average LBP VAS improvement from 6.5 to 2.4, leg VAS from 5.7 to 1.5, and ODI from 35 to 6. Stenosis patients had LBP VAS from 6.1 to 3.7, leg VAS from 6.0 to 2.2, and ODI from 41 to 29. DDD patients had LBP VAS from 6.8 to 4.6. Within groups, HNP had significant improvement at all follow-ups for VAS back & leg pain, Pain Diagram, ODI, and PROMIS-Phys. Stenosis patients had significant improvement at all FU <8 months for VAS back & leg pain, Pain Diagram, ODI, and PROMIS-Phys. DDD group had significant improvement at all FU for VAS back pain. Between groups, there was no difference in pretreatment measures. HNP had significantly greater improvement in VAS back & leg pain, & ODI compared to DDD.HNP had significantly greater leg pain improvement compared to Stenosis. Stenosis patients had significantly greater improvement in VAS leg pain compared to DDD. HNP patients had the greatest reduction in pain medications. Of patients that failed AF, 2 HNPs had discectomy and 4 DDDs had fusion/TDR which is dramatically less surgery than in prior steroid injection studies by the authors

CONCLUSIONS

AF epidural injections are most effective for patients with lumbar HNP and moderately effective for those with stenosis. AF injections for DDD patients gave inconsistent results. Future prospective studies of AF vs steroid injections are warranted for HNP and stenosis patients.