Injections are an invasive technique that can diagnose the cause of pain, and can treat the pain itself. The great thing about injections for back pain is that they deliver medicine directly to the site of the pain. The amount of pain relief from injections vary from temporary to long lasting.
Although there are many types of medications used for injections, injections themselves are broadly categorized according to what type of tissue, body system, or location receives the shot.
Epidural Steroid Injection (ESI)
An ESI is a common type of injection that is given to provide relief from certain types of low back and neck pain. The "epidural space" is the space between the covering of the spinal cord (dura mater) and the inside of the bony spinal canal. It runs the entire length of your spine. When injected into this area the medication moves freely up and down the spine to coat the nerve roots and the outside lining of the facet joints near the area of injection. For example, if the injection is given in the lumbar spine, the medication will usually affect the entire lower portion of the spine.
The epidural needle is inserted into the back until the doctor feels sure it is in the epidural space. The doctor will then place a small amount of lidocaine into the epidural space and wait to see if you feel warmth and numbness in your legs. If so, the needle is most likely in the correct position. The remainder of the medication is injected and then the needle is withdrawn.
Facet Joint Injection
Facet joint injections are used to localize and treat low back pain or neck pain caused by problems of the facet joints. These joints are located on each side of the vertebrae. They join the vertebrae together and allow the spine to move with flexibility. The facet joint injections form a pain block that allows the doctor to confirm that a facet joint is causing the pain. The medication used also decreases inflammation that occurs in the joint from arthritis and joint degeneration.
It is important to make sure that the injection goes directly into the facet joint. Fluoroscopy can be used to confirm that the needle is in the right position before any medication is injected. A fluoroscope uses X-rays to show a TV image. Your doctor can watch on the screen as the needle is placed into the joint and magnify the image to increase accuracy.
A facet joint injection is perhaps the best way to diagnose facet joint syndrome. Joints that look abnormal on an X-ray may in fact be painless, while joints that look fine may actually be a source of pain. This is a rather simple procedure with little risk.
SI Joint Injection
Sacroiliac (SI) joint pain is easily confused with back pain from the spine. The SI joint is located between the sacrum and pelvic bones. Sometimes injecting the SI joint with lidocaine may help your doctor determine whether the SI joint is the source of your pain. If the joint is injected and your pain does not go away, it is probably coming from somewhere else. If the pain goes away immediately, your doctor may also inject cortisone into the joint before removing the needle. Cortisone is added to treat inflammation from SI joint arthritis. The injection usually gives temporary relief for several weeks to months.
Trigger point injection (TPI)
Trigger points are tight nodules located in skeletal muscles that when touched or pressured, produce tenderness, twitching and jumping. These responses are due to what the doctors call 'hyperirritability' of the trigger point. Trigger points cause a condition known as myofascial pain syndrome. The trigger points produce pain locally (right where they are) as well as often referring pain to other areas. Very often the muscles most affected with trigger points are the muscles.
TPI is a procedure used to treat painful areas of muscle that contain trigger points, or knots of muscle that form when muscles do not relax. Many times, such knots can be felt under the skin. Trigger points may irritate the nerves around them and cause referred pain, or pain that is felt in another part of the body. The injection contains a local anesthetic that sometimes includes steroids. With the injection, the trigger point is made inactive and the pain is alleviated. Usually, a brief course of treatment will result in sustained relief. Injections are given in a doctor's office and usually take just a few minutes.
Bursa injections are given in the case of bursitis. Usually corticosteroids are the medications used for soft tissue injections. Soft tissue injections decrease the inflammation in the bursae and can relieve constant joint pain. A common area for the injection is the hip bursa (greater trochanter bursa).
Botox injections have been tried for the management of back and neck pain, as well as headaches. Botox is a medication that can temporarily paralyze nerves. The theory behind using Botox as back and neck pain medicine is that it interrupts the signals that go from nerves to muscles, and increases range of motion.
Joint injections are usually performed under local anesthesia in the office or hospital setting. They are given to treat inflammatory joint conditions, such as rheumatoid arthritis, psoriatic arthritis, gout and occasionally osteoarthritis. Corticosteroids are frequently used for this procedure as they are anti-inflammatory agents that slow down the accumulation of cells responsible for producing inflammation within the joint space. Commonly injected joints include the knee, shoulder, ankle, elbow and wrist and small joints of the hands and feet. Hip joint injection may require the aid of an X-Ray called fluoroscopy for guidance.