Back and neck pain can sometimes be caused by a disc bulge or herniation that presses on a nearby nerve root branching off from the spinal cord. This can cause painful inflammation around this nerve root. The symptoms can include pain that radiates into an arm or leg, or weakness/numbness in a hand or foot. For these symptoms, a spinal injection can relieve inflammation and symptoms long enough for the person to bridge back into therapy and activity.
Injections are often recommended because they have a dual purpose. “The purpose of a spinal injection is both therapeutic and diagnostic,” explains Dr. Eric Mayer, a fellowship-trained specialist in Physical Medicine & Rehabilitation at Texas Spine & Scoliosis. “If back pain symptoms respond to the injection at a certain disc level, we can then confirm that particular disc is the pain generator. So even if the relief is temporary, the injection can provide the surgeon valuable information that will help ensure a successful surgery if and when it becomes necessary.”
How injections work
When a disc herniates it can press on adjacent nerve roots that branch off from the spinal cord. Surgery doesn’t repair the disc wall, but rather removes the herniated tissue which in turn relieves the pressure on the nerve root.
Another way to relieve pressure on a nerve root is to inject pain medication directly to this area which reduces inflammation and pain symptoms. When spine physicians choose to use injection therapy, their ultimate goal is to relieve pain long enough to enable the patient to begin physical therapy.
During an injection procedure, the patient lies on his or her stomach to enable a C-arm fluoroscopic device to provide X-ray images of the spine. Local anesthetic may be injected into the skin and underlying tissues to reduce discomfort from the injection.
Next, a thin needle is inserted into the epidural space, with the vertebrae serving as landmarks. The physician views images from the C-arm to make sure the needle is positioned correctly. Once the needle enters the epidural space, a syringe containing corticosteroid solution is connected to it and the solution is injected.
“Years ago, a spine physician might arbitrarily perform a series of three injections,” explains Dr. Lee Moroz, a specialist in Physical Medicine & Rehabilitation. “That is no longer the case. Typically, you are unlikely to benefit from repeated epidural steroid injections if the first or second does not provide relief.
“If the injection provides relief of symptoms, we may refer the patient to a spine therapist,” adds Dr. Moroz. “This may include some customized stretches to strengthen the back, make it more flexible and resistant to future strain. In many cases, these injections can bridge many patients back to activity without surgery.”