What is it?
A Lumbar epidural injection usually takes between 15 and 30 minutes and carries an anti-inflammatory steroid such as cortisone to the inner part of the spine where the more serious types of strain and injury can affect the disc and spinal joints, causing pressure or irritation of the nerves, or pain arising from the joints. It delivers the steroid as close as possible to the anatomical structure causing your pain, thus providing the greatest chance of pain relief.
What does the procedure involve?
An needle will be placed in your arm in case any medication is needed during the procedure. The patient lies on their side or on their front. Prior to the injection, the skin is numbed with lidocaine. Sedation is available if required but the procedure is usually not uncomfortable.
The physician directs a needle into the lumbar spine through a thick ligament called the ligamentum flavum into the spinal canal (epidural space). Once the needle is in the exact position, the epidural steroid solution is injected. Following the injection, the patient is usually monitored for about 2 to 3 hours before being discharged home and normal activities may typically be resumed the following day.
What happens next?
The injection should provide pain relief for one week, up to one year, and should allow the patient to progress with their rehabilitation program. If a patient does not experience any pain relief from the first epidural injection, further injections will probably not be beneficial. However, if there is some improvement in pain, one to two additional epidural steroid injections may be recommended.
Are there any risks?
As with all invasive medical procedures, there are potential risks associated with lumbar (lower back) epidural steroid injections. Generally, however, there are few risks associated with epidural steroid injections and they tend to be rare. Risks may include:
- Infection. Minor infections occur in 1% to 2% of all injections. Severe infections are rare, occurring in 0.1% to 0.01% of injections.
- Bleeding. Bleeding is a rare complication and is more common for patients with underlying bleeding disorders.
- Nerve damage. While extremely rare, nerve damage can occur from direct trauma from the needle, or secondarily from infection or bleeding.
- Dural puncture (“wet tap”). A dural puncture occurs in 0.5% of injections. It may cause a post-dural puncture headache (also called a spinal headache) that usually gets better within a few days. Although rare, a blood patch may be necessary to alleviate the headache.
- Paralysis is not a risk since there is no spinal cord in the region of the epidural steroid injection.
Will I have any side effects?
Side effects are rare but may include:
- High blood sugar
- Stomach ulcers
- Severe arthritis of the hips (avascular necrosis)
- Transient flushing
- Increased appetite
How often can I have a spinal injection?
Most medical professionals feel that it is very safe to inject the same joint or epidural space up to three times per year.
How long does the numbing last?
Due to the numbing medicines, some patients experience numbness in the arms or legs after the procedure. The numbing medicine wears off in one to eight hours, causing the numbness or weakness to go away.
How long will it take before I experience pain relief?
Increased pain is often experienced the evening after the injection and the following day. Although unusual, this pain may last up to seven days. The benefits from the cortisone-type medication injected generally take 24 to 72 hours to occur. Occasionally, it can take ten days for beneficial affects to occur. The medication usually reaches its peak effect by three weeks.
How long will the benefits of the injection last?
If the injection relieves 75% to 100% of your pain one to two weeks after the injection, most likely the results will be long lasting, if the problem that caused the inflammation in the first place is removed. In some cases, the injection will not work because:
1. The medicine was not put in the proper place where the pain is coming from. Your doctor should reassess your history and physical examination to re-diagnose the problem. Although disappointing, an injection that does not provide pain relief often helps to correctly diagnose your problem.
2. The medicine was put in the proper place, but the problem causing your pain, such as a large slipped disc or severe spinal stenosis, is too great to be overcome by a simple injection. When this is the case, the patient will generally experience some very minor pain relief for several days and then the pain will be as bad as it was previously. When this occurs, it is generally not worthwhile performing any further injections.