Spinal cord stimulators are electrical devices that are surgically implanted in the body to treat long-term pain. They have a battery pack and leads that deliver electrical impulses directly to the spinal cord. The devices are thought to work by providing electrical impulses that interfere with how the brain senses pain.
Spinal cord stimulators are mainly used to treat chronic back pain, especially when other less invasive treatments have not worked. They also aim to reduce people’s reliance on risky pain medicines. These include opioids, which research shows are ineffective and harmful for low-back pain.
But research, including our own, shows spinal cord stimulators work no better than a placebo. And they can also carry risks.
Do they work?
In a 2023 Cochrane review, researchers reviewed data from 13 randomised controlled trials on low-back pain and found no benefits in the short and medium term. These international reviews draw together the most robust evidence to provide a detailed summary of what we know on a particular topic.
Only one of the trials in the review tested efficacy in the longer term (six months). That trial found no benefits of spinal cord stimulation.
An earlier Cochrane review looked at the evidence of spinal cord stimulation for chronic pain in general, including for neck pain. Reviewers looked at 15 randomised controlled trials and couldn’t be certain about its benefits, largely due to the quality and reliability of the available trials.
Are there side effects?
Aside from disappointing results for pain relief, there are risks and side effects to consider.
We co-authored an analysis of 520 adverse events reported to Australia’s Therapeutic Goods Administration (TGA). We found 79% of reported events were rated as severe, with 13% life-threatening. The same research found 80% of events required surgery to correct.
Our recent analysis in the Medical Journal of Australia looked at data from private health insurers. These cover 90% of spinal cord stimulation implants in Australia. Five major insurers, which covered 76% of privately insured people, contributed de-identified data.
We found about one-quarter of people who had a spinal cord stimulator implanted needed corrective surgery afterwards. These surgeries occurred within a median of about 17 months. This indicates these surgeries are not routine or expected interventions, such as to replace batteries, which are meant to last five to ten years.
Our previous research shows the sorts of reasons for corrective surgery. These include to replace a malfunctioning device, or the person was in more pain, had an infection, or a puncture of the delicate tissues covering the spinal cord.
However, even our latest findings are likely to underestimate the risk of these devices.
Sometimes the lead delivering the electrical current moves away from the spinal cord to elsewhere in the body. This requires surgery to reposition the lead, but does not necessarily require new hardware, such as a brand new lead. So this type of corrective surgery is not counted in the data from the private health insurance companies.
How much does it cost?
We found spinal cord stimulators cost about A$55,000 per patient, including the device, its insertion, and managing any associated additional surgeries.
For people who only had a “trial” – where the leads are implanted temporarily but the battery pack remains outside the body – this cost was about $14,000 per patient.
These figures do not include any out-of-pocket costs.
What do regulators say about the devices?
In 2022 the TGA began a review of spinal cord stimulators on the market because of safety and performance concerns.
As a result, several devices were removed from the Australian Register of Therapeutic Goods – that is, they were banned from use in Australia, but existing stock could still be used.
The rest of the devices had conditions imposed, such as the manufacturers being required to collect and report safety data to the TGA at regular time points.
Should I do my own online research?
Yes, but be careful. Unfortunately not all online information about spinal cord stimulators is correct.
Look for sites independent of those who manufacture or implant these devices.
Government agencies, health departments and universities that have no financial interests in this area may be a better option.
The Cochrane Library is also a reliable and independent source for trustworthy health information.
What shall I ask my doctor?
The Australian health department provides useful advice for consumers about medical implants.
It says medical implants “are considered higher-risk therapeutic goods, and the decision to get one should not be taken lightly”. It recommends asking your health professional these questions:
do I really need this medical implant?
what are the risks/benefits?
is the medical implant approved?
where can I get more information?
what happens if I experience an adverse event?
What else could I do for my back pain?
There are other treatment options that are effective and have fewer risks than spinal cord stimulation.
For example, education about how to manage your pain yourself, exercise, cognitive behavioural therapy (a type of psychological therapy), and non-steroidal anti-inflammatory medicines (such as ibuprofen) all have solid evidence to back them. All offer benefits that are not outweighed by their potential risks.
Australian research has shown other types of therapy – such as sensorimotor retraining and cognitive functional therapy – are also effective. You can discuss these and other options with your health professional.
Spinal cord stimulation is a good example of a treatment that got ahead of the evidence. Although the devices have been around since the 1960s, we’ve only had reliable trials to test whether they work in recent years.
Everyone wants to find ways to help people with chronic pain, but we must ensure medical care is grounded in reliable science.
Christopher Maher holds a research fellowship funded by the National Health and Medical Research Council.
Caitlin Jones does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
This article was originally published on The Conversation. Read the original article.
