For managing intractable chronic low back pain, the Food and Drug Administration (FDA) has recently approved a new implantable neurostimulation system “Mainstay Medical”. This device can assist to manage chronic low back pain linked with multifidus muscle dysfunction. This is evidenced by physiological testing or imaging, in individuals who are not candidates for spine surgery and have failed physical therapy and pain-relieving medications.

As the implantable neurostimulation device passes the transverse process at the L3 branch, a bilateral electrical induction is induced by the device in the L2 medial branch of the dorsal ramus nerve. This stimulation induces muscle contraction, which can lead to remarkable improvements in back pain and its deteriorating effects.

For each user, stimulation can be customized since an external programmer helps to communicate wirelessly with the implant. With the help of an external wireless activator, the stimulation sessions are activated twice a day and are usually 30 minutes long.

Based on results from a randomized, prospective, active sham-controlled blinded trial, this implantable neurostimulation system was approved. The study incorporated 204 patients implanted with Mainstay Medical. Low stimulation (no anticipated effect) to the control group and adequate stimulation (sufficient to induce episodic multifidus muscle contractions) to the treatment group were delivered by this device.

Comparing responder rates between the treatment and control arms as estimated on pain visual analog scale (VAS) was the primary outcome ascertained. A ≥30% improvement between baseline and 120 days after randomization, without a considerable elevation in pain medication taken two weeks before the primary endpoint assessment visit, were defined as responders.

The responder rate at 120 days did not show a statistically significant difference, as shown in the following table:

Of 60 subjects who crossed-over to the treatment group from the control group, about 68% were deemed responders. Furthermore, among participants who took opioids at baseline, treatment with Mainstay Medical was linked with a voluntary decline in medication usage.

Thus, this novel Mainstay Medical fills a vital unmet clinical need of individuals suffering from chronic low back pain. It yields substantial improvements in quality of life, back pain, and its disabling impacts. In 2021, the device is anticipated to be available in the United States.