Injections and Implants for Back Pain Relief

By Suzanne Wright | May 21, 2021

People try many treatments for back pain, from physical therapy and medications to acupuncture and massage. In some cases, though, pain is incapacitating, and more aggressive treatment is needed. While injection treatments may help back pain and sciatica, only a few of these procedures are used for osteoarthritis (OA) or inflammatory forms of arthritis.

Injections for back pain are used to deliver anti-inflammatory pain relief medication locally, right to the affected area. Patients who continue to need pain management even after surgery for back pain or sciatica may get relief from an implanted device.

“There are many different underlying causes for back pain, and there are different injections which address these possible causes,” says Robert S. Griffin, MD, PhD, a pain physician at New York’s Hospital for Special Surgery.

Doctors may try several different types of injections for back pain, beginning with the most conservative treatment. The best approach for you will depend on your particular problem.

Dr. Griffin says trigger point injections are the lowest risk procedure, followed by sacroiliac joint injections for pain in the sacroiliac joints (the joints between the hip bones and a bone at the base of the spine). Spinal injections, including facet joint injection, facet radiofrequency ablation and epidural steroid injections, all have higher but similar risks. And spinal cord stimulation and implanted drug infusion systems are potentially the riskiest of the procedures discussed here.

“All of these procedures can be helpful for patients with the relevant type of back pain and can be useful in patients who vary across age and gender,” Dr. Griffin explains. 

He adds that neuromodulation systems (dorsal root ganglion stimulation) is a promising new treatment that may be useful for people with localized neuropathic pain, such as complex regional pain syndrome.

INJECTIONS

• Epidural Glucocorticoid iInjections. When inflammation within the spinal column causes nerve-root irritation and swelling, a doctor may administer a potent anti-inflammatory medication to reduce inflammation and ease pain. Glucocorticoids (a type of corticosteroid, or “steroid”) typically are injected directly into the epidural space — the area just inside the spinal canal but outside the connective tissue layer (the dura mater) encasing the spinal fluid, spinal cord and spinal nerves. These injections are intended to deliver pain-relieving medication directly to the site of inflammation. Pain relief typically begins in less than a week and lasts anywhere from several days to a few months.

“These are most useful for radicular pain (pain from a spinal nerve root which is inflamed and/or compressed) associated with disc herniations or spinal stenosis,” says Dr. Griffin. Risks include severe infection, bleeding, nerve injury, lack of success, post procedure pain or allergic reaction to the medication or contrast dye commonly used in the procedure. An inadvertent puncture of the dura mater can cause headache. Facet blocks and radiofrequency ablation have similar risks.

Additionally, Dr. Griffin warns that patients taking blood thinning medication should talk to their cardiologist about temporarily halting it for the procedure; if that’s not possible, forgoing this procedure might be the best choice.

“Patients with diabetes or high blood pressure may have exacerbations of these problems temporarily following the injection due to the side effects of steroids,” Dr. Griffin says. “Frequent steroid injections can also increase the risk of osteoporosis.”  

• Transforaminal Epidural Steroid Injection. When a nerve root is compressed or inflamed, it can cause pain in the back and leg. A transforaminal epidural steroid injection, sometimes called a selective nerve-root block, is an injection of a glucocorticoid and/or numbing agent into the area of the nerve where it exits the spinal column between the vertebrae. Pain relief begins within a few days to a week and may last up to a few months.

• Facet Joint Block. If your doctor suspects the source of your pain is in the facet joints, where the vertebrae connect to one another, she may recommend a facet joint block, or facet joint injection. People with facet joint pain from osteoarthritis may benefit from this procedure, in which a corticosteroid and/or anesthetic medication is injected directly into the joint capsule. Pain relief may last several weeks or months. (Facet joint pain from rheumatic conditions, such as axial spondyloarthritis, are typically treated with medications, although a facet joint injection or facet neurotomy might be considered for symptom relief, Dr. Griffin adds.)

• Facet Neurotomy. This procedure may help if a facet joint block indicates that a particular joint is the source of back pain, possibly from OA. A heated needle is used to remove and disable the nerve responsible for the pain. Although the nerve usually grows back, allowing pain to return, the pain relief can last for several months to a year.

Also called “facet radiofrequency ablation,” Dr. Griffin says, “[it] is used for chronic facet joint pain, is frequently successful, and can provide prolonged relief — frequently eight to 12 months at a time.” Risks are similar to those of epidural injection, but steroids aren’t necessary, which poses fewer issues for those with diabetes, high blood pressure or osteoporosis.  

• Sacroiliac Joint Injection. These involve injecting an anesthetic or anti-inflammatory medication into the sacroiliac joint, which connects the sacrum (one of the sections of the spine, composed of five fused vertebrae) to the pelvis. It may be used to relieve low back pain that results from inflammation or damage within the sacroiliac joint, in some cases resulting from a rheumatic condition.

“Sacroiliac pain is often felt as an aching pain over the sacral area, which is painful with prolonged sitting or standing,” explains Dr. Griffin. “These injections still have the risk of joint infection, which can be quite serious, but risks of bleeding and nerve injury are much lower.”

• Trigger Point Injections. Used for muscle pain, these inject a small amount of anesthetic, sometimes along with a corticosteroid, directly into painful trigger points — specific sites that cause pain (both locally and throughout the back) when your doctor presses on one during an exam.

“Trigger point injections are used for local muscle spasm,” says Dr. Griffin. “They are frequently helpful and are most successful for acute spasms since they do not usually have a long duration of action. Risks are very low, since the needles are not intended to reach the spine.”

Implantable Devices
Two types of implantable devices are used to treat back pain — those that deliver electrical stimulation and those that deliver medication to the spinal cord.

• Spinal Cord Stimulation. Spinal cord stimulation is believed to decrease the perception of pain by activating nerves in the lower back to block pain signals going to that area. As a result, pain is replaced with a pleasant tingling sensation. Spinal cord stimulation is delivered through a set of electrodes inserted between the vertebrae into the epidural space. A pulse generator surgically placed under the skin, usually in the abdomen or the upper buttocks area, activates the electrodes. The procedure may be appropriate for people with nerve-root injuries that haven’t responded adequately to conventional treatment and those for whom surgery has not been successful. They do not generally help with pain from arthritis.

“Spinal cord stimulation is primarily useful for patients who have continuing nerve-related pain after spine surgery was done to alleviate any nerve compression,” Dr. Griffin explains. “There can be risks associated with the implantable device, including device failure, lead migration and device infection. There can also be pain at the battery site. Most of these can be treated with removal or revision of the system. In some patients, over time there is the risk of developing pain which ‘breaks through’ the stimulation.” 

• Implanted Drug Infusion. Also called intraspinal drug infusion therapy, this involves implanting a pump in the body to deliver a regular, predetermined dose of opioid pain medicine via a tube into the painful area of the spine. By targeting medication to the precise site where the medication activates, much smaller amounts of opioids are necessary to control pain than if taken orally or by injection, and the risk of side effects is also much lower.

However, Dr. Griffin says, “Implanted drug infusion systems are highly controversial for back pain and are most useful for cancer pain.”