Following implantation of a restorative neurostimulation system significant improvements were observed in pain, disability and quality of life compared to baseline in patients with chronic refectory low back pain.
The ReActiv8-A trial was prospective single arm clinical trial with the purpose of collecting performance and safety data on a new implantable restorative neurostimulation system for patients with chronic refractory low back pain. The results were presented by Vivek Mehta, St Bartholomew’s Hospital, London, United Kingdom at the World Congress of the World Institute of Pain (WIP; 9–12 May 2018, Dublin, Ireland).
Bilateral stimulation of the medial branch of the L2 dorsal ramus elicits episodic contractions of the lumbar multifidus and reactivation of lumbar multifidus motor control and restoration of dynamic stability has been a hypothesised mechanism of action facilitating recovery.
The trial enrolled 53 subjects (age 44±10 years, pain duration 14±11 years) who were implanted at nine centres in Europe and Australia. Selection criteria included disabling chronic refractory low back pain despite 90-days of medical management, no indications for spine surgery and no prior surgery. Subjects administered 30-min stimulation sessions twice daily for a minimum of 90 days. Measures recorded were numerical rating scale (NRS) for pain, Oswestry Disability Index (ODI) for disability, EQ-5D for quality of life and treatment satisfaction.
Utilising matched data, significant improvements (p<0.001) were observed in pain, disability, and quality of life compared to baseline. NRS (6.8±0.2 at baseline) improved 35%±5% at 90-days (n = 52), 32%±5% at 6-months (n=51) and 33%±6% at 1-year (n=47). The proportion of subjects with a clinically important improvement one or more of the numerical rating scale, the Oswestry Disability Index and EQ-5D were 94%, 86% and 87% respectively. Similarly, 89%, 84% and 81% reported being satisfied or very satisfied with the treatment. There were no unanticipated adverse events and no serious therapy related adverse events.
The study concluded that neurostimulation to contract the lumbar multifidus appears to be a safe and effective treatment option for these patients with chronic refractory low back pain.