Sacroiliac joint injections

The sacroiliac joints are large joints that connect the base of the spine, called the sacrum, to the iliac bone of the pelvis. Sometimes these joints themselves become painful causing back, buttock and leg pain. By injecting these joints with a combination of local anesthetic and steroid, this type of pain often can be controlled.

Besides injecting too much steroid leading to steroid toxicity, there are not many complications related to this procedure. To enter the joint, this procedure must be performed by your doctor using fluoroscopic guidance. Figure 14 shows the sacroiliac joint. This is a simple procedure with the patient on their belly. It takes approximately 5 minutes and is very effective for pain that is coming from the sacroiliac joint.

Figure 14: The sacroiliac joint

Sympathetic nervous system blocks

The nervous system of our body is divided into two very separate nervous systems, one system that we can voluntarily control (ie, the system that controls the use of our arms, hands, legs, feet, and our facial expressions) and another system that we have no control over (ie, the system that controls bodily functions such as blood flow, heart function). The system that we can control is called the voluntary nervous system, and the one that we have no control over is called the involuntary nervous system.

The involuntary nervous system is further divided into that part that excites the functions of the body (the sympathetic nervous system) and the part that inhibits functions of the body (the parasympathetic nervous system). Normally these two systems are in balance, but when they are in imbalance, problems may arise. Some pains of the spine occur if there is excessive sympathetic energy or "tone." We call this type of pain sympathetically maintained pain or SMP.

Your physician may be able to "block" the sympathetic nervous system or "sympathetic chain" by injecting local anesthetic to numb a target area. For example, if a patient has neck, arm, or hand sympathetically maintained pain, blocking the sympathetic chain in the neck may be helpful. The sympathetic chain in the neck comes together in what is called the stellate ganglion.

Sympathetically maintained pain in the low back, legs or feet may be relieved by a lumbar sympathetic nerve block. If blocking the nerve with local anesthetic helps, but only helps for a short time, the lumbar sympathetic chain or the stellate ganglion can be permanently blocked either surgically or by radiofrequency thermocoagulation.

Sympathetically maintained pain (SMP) can be caused by any injury to the arms, legs, hands, feet, neck, or back. This is a type of neuropathic pain, pain that is caused by abnormal functioning of the nervous system. SMP typically causes burning, tingling, jolting and electrical sensations in the affected area. They may be associated with swelling of the extremities, increased sweating of the area and changes in color to the area. Diagnoses associated with SMP that may be helped by these blocks include trauma to the neck, arms, hands, back, legs or feet, failed back surgery syndrome (failure of neck or back surgery), complex regional pain syndrome (CRPS), which used to be called reflex sympathetic dystrophy (RSD), or diabetic neuropathy.

Continuous epidural analgesia

Sometimes pain in the back or neck may be so debilitating that it interferes with normal activities of daily living. Sometimes this severe pain may not respond to the medications or blocks. Continuous epidural analgesia can provide fast and continuous pain relief for a relatively short period of time.

These procedures are usually performed in a hospital setting, but some doctors discharge patients home with their catheters. If patients have continuous epidural analgesia at home, then they and their families must always preserve the sterility of the exiting catheter. Usually, home care nurses and home infusion companies provide care.

Figure 15 shows that the epidural space is surrounded by bone and it is the space that nerve roots go through on their way outside of the spine to their respective targets, either the arms in the neck or the legs. By placing a catheter through a needle placed into the skin of the back and into the epidural space, your doctor can deliver local anesthetics into the space. This blocks the exiting nerves while providing pain relief. In this case, the catheter that exits the skin is covered with a sterile dressing to prevent skin infections and epidural infections.

Figure 15: The circle in red is an epidural catheter providing continuous infusion of a pain reliever directly to the affected area to block the nerve root that is exiting the spinal canal in the epidural space.

Continuous infusions via an implanted catheter should only be considered as temporary relief until a more lasting therapy is found. Other medications may be used in the continuous epidural catheter including opioid medications, such as morphine, and drugs that have been used typically for hypertension, such as clonidine.

The major complications of epidural anesthesia are infection, penetration of the thecal sac, spinal cord damage, and respiratory depression if opioids are used. One major drawback to the use of this technique is that it is not useful in conditions where pain is in many different spots of the body, as the epidural catheter is in a fixed position in the epidural space.

Neurolytic (destruction of nerves) techniques

Neurolysis, or destruction of nervous tissue, may be performed by physicians either surgically or by heating with radio frequency thermocoagulation (RFTC) or freezing by cryoneurolysis. These neurolytic techniques provide longer pain relief than when the nerves are injected with local anesthetics. Pain relief may last several months to even a year.

In the past, doctors used to use chemical neurolytic agents. Now, the most common technique is RFTC. Chemicals, especially very concentrated sugar solutions mixed with phenol or glycerol are being injected into muscles and ligaments of the back, sacrum or neck, not to destroy them, but to strengthen them after healing takes place. The injection of strengthening agents is called prolotherapy.

Using heat to destroy neural tissue can help relieve pain. This technique uses a radiofrequency generator system. Electrical currents generated by the radiofrequency generator heat tissue surrounding the needle tip. This raises the temperature of the electrode tip which produces the thermal lesion. For our discussion of spine pain, RFTC has been used for thermal lesioning of the nerves to the cervical, thoracic and lumbar facet joints, the sacroiliac joints, the cervical and thoracic sympathetic chain, the lumbar sympathetic chain, and the cervical, thoracic, lumbar, and sacral dorsal root ganglia. These ganglia are rounded neural tissue of the nerves, just before the nerve leaves the spinal canal.

Specific mini-invasive surgical therapies for spine pain

Surgical spine procedures for neck or back pain are either minimally invasive, which means they require little entry into the body, or surgically invasive, which means they are major operations. The minimally invasive procedures are usually done with needles and x-ray and sometimes in the operating room with small incisions and instrumentation that allows a surgeon to remove the pain generator. Following are some of the more common minimally invasive techniques.

• Thermal lesioning techniques of the disc including intradiscal thermocoagulation (IDET), annuloplasty of the annulus and nucleoplasty
• Disc nuclear volume reduction techniques including microdiscectomy and percutaneous disc removal techniques
• Percutaneous vertebroplasty or kyphoplasty, used for vertebral pain from fractures of the vertebral bodies caused by osteoporosis

Intradiscal thermocoagulation (IDET)

The disc is made up of an inner gel-like material, the nucleus, surrounded by the fibrous annulus. The intervertebral disc acts as the body's shock absorber.

As we age or if we sustain a repetitive injury, the discs in our backs lose water and become brittle. This makes the discs more likely to crack. If the annulus cracks, nuclear material leaks through these cracks and can bulge out of the disc into the epidural space. This bulging nuclear material can irritate exiting nerve roots causing a radiculopathy (pain and neurologic dysfunction from the nerve root) or even sensitize pain receptors in the disc itself, causing discogenic pain.

Radicular pain starts in the back and radiates outward toward the neck and into the arm or toward the back, buttock and into the leg and foot. Radicular pain increases with walking or bending forward or when the arm or leg is extended. Discogenic pain increases with sitting and walking and also increases with forward bending. Discogenic pain usually is only felt in the neck or back.

Intradiscal thermocoagulation (IDET) is a technique that uses heat to destroy part of the nucleus and inner annulus of the disc. This can decrease the size of the nucleus, which allows for the nuclear material that has leaked to re-form in the center of the disc. This decreases an individual's pain. It also destroys pain sensitive receptors in the fibrous annulus, thereby reducing pain in the back. Figure 16 shows a cartoon of an IDET heating coil in the nucleus of the disc that was placed there through a needle under fluoroscopic guidance.

Figure 16: This drawing the IDET heating coil within the nucleus of the intervertebral disc, placed through a needle under fluoroscopic guidance. The red depicts a burn or thermal lesion.

The possible risks of the IDET procedure include infection of the disc, epidural infection, or burn of the nerve root, which can result in weakness or paralysis of the legs as a result. In general, however, this procedure is safe and these complications are very rare.

Annuloplasty

Annuloplasty, like IDET, creates a thermal lesion (burn) in the disc. The difference is that the thermal probe of the annuloplasty procedure creates its thermal lesion through radiofrequency energy and the target for burning is the annulus. Some researchers believe that this procedure seals up the cracks in the annulus, thus preventing further leaks of the pain-generating nuclear material.

Figure 17 shows a annuloplasty heating probe within the annulus. Notice that the heating element with annuloplasty is closer to the nerve root than the element used with IDET. This does not mean that it is not as safe as the IDET procedure. Complications of this procedure are the same as with the IDET procedure.

Figure 17: An annuloplasty heating element within the annulus of a low back spinal level. Notice that the element is fairly close to the exiting nerve root.

Nucleoplasty

Nucleoplasty is a surgical procedure that reduces the volume of the nucleus. The surgeon uses a needle, guided by fluoroscopic x-ray, to introduce a special instrument into the nucleus. The surgeon's goal is to pull leaking nuclear material back into the center of the nucleus. This procedure is performed using a special "wand" as seen in Figure 18.

Figure 18: Nucleoplasty. The wand is moved back and forth in the nucleus creating destroyed nuclear channels, thereby decreasing volume of the nucleus.

Disc decompression and removal

The idea behind removing the disc is that you are removing the pain-causing nuclear material. Consequently, your pain is relieved. Removal of nuclear material can be performed mini-invasively using laser, a nucleotome, or a disc decompressor. The end result is the same with each of these procedures — that is removal of some of the nucleus.

Surgically, the disc can be removed with either a small incision using a microscope (microdiscectomy) or through a larger incision and removal of part of the spinal bone toward the back called the lamina as in laminectomy and discectomy. The "ectomy" at the end of the words means removal. So, laminectomy means removal of the lamina and discectomy means removal of the disc.

Removal of a disc is somewhat controversial. It is unclear whether removal of the discs ends up causing other problems. Remember the disc is the body's shock absorber, and when the disc is removed, the space between the discs decreases to a point that sometimes the vertebral bodies touch each other, resulting in loss of "disc height." Some surgeons prefer fusing vertebral bodies together when the discs are removed. To answer this problem, many device and pharmaceutical companies are trying to make a safe and effective artificial disc to replace damaged discs.

Vertebroplasty and kyphoplasty for compression fractures

FAST FACTS:

• More than 700,000 vertebral (spinal bone) fractures occur each year, usually in women over the age of 60.
• Researchers estimate that at least 25% of women and a somewhat smaller percentage of men over the age of 50 will suffer one or more spinal fractures.
• Compression fractures in older individuals lead to loss of height and what is often called a "hunchback" at the upper back.
• Compression fractures often are very painful, and the pain usually lasts for one to three months.
• Patients may get either one or more compression fractures. Because the bones are soft, it is more likely that patients get more than one compression fracture in the natural course of their lives.

When we get old, our bones begin to lose calcium, making them softer than when we were young. A soft disc is prone to collapse in what is called a "compression fracture."

In the past, individuals with compression fractures had to live with their pain or take short-acting opioid medications or non-steroidal anti-inflammatory medications to help relieve their pain. Today, neurosurgeons, orthopedic surgeons, some radiologists and some pain doctors perform either vertebroplasty or kyphoplasty to relieve pain related to compression fractures. These procedures give rigid structure to soft vertebral bodies and stop pain from the fractures. Both of these procedures involve placing plastic cement into the vertebral bodies by using a needle guided by fluoroscopic x-ray.

Vertebroplasty is a minimally invasive, non-surgical therapy used to strengthen a spinal bone (vertebra) that has been weakened or broken by osteoporosis or, less commonly, cancer. Vertebroplasty usually is successful at alleviating the pain caused by a compression fracture and is usually performed on an outpatient basis, using local anesthesia. Studies indicate that 85% to 90% of patients who undergo this therapy experience immediate pain relief.

Kyphoplasty also involves putting cement into the broken bone, but is a different procedure. Kyphoplasty is commonly done under general anesthesia in an operating room. In kyphoplasty, a balloon catheter, similar to the one used in angioplasty of the heart, is guided into the vertebral body and inflated with a liquid under pressure. As the balloon inflates, it can help to actively restore the collapse in the vertebra caused by the fracture. After the balloon is completely inflated, it is deflated and removed. The large cavity created by the enlarged balloon is filled with bone cement. The cement then hardens in place, maintaining any correction of collapse or wedging of the bone.

Kyphoplasty can be very helpful when there is severe collapse of the broken vertebra or wedging, with more collapse in the front of the spine than the back resulting in the spine tending to tilt forward. By correcting the wedging, kyphoplasty may help restore the spine to a more normal alignment and prevent severe "hunchback" deformity to the spine. In someone who has had multiple fractures with previous wedging, kyphoplasty can prevent further worsening of the deformity.

Invasive Spine Surgery

We will limit our discussion of major spine surgery to laminectomies, discectomies, foraminotomies and fusions. We will not attempt to be exhaustive in our discussion of the pros or cons for each procedure, or even the risks of each procedure, but will discuss why these techniques are used.

Invasive spine surgery requires general anesthesia and may or may not require a postoperative hospital stay. These procedures are intended to correct abnormal spinal pathology or remove abnormal spinal pathology. These procedures include:

1. Decompressive laminectomy – In this procedure, a surgeon increases the volume of the spinal canal by removing the "roof" of the spinal canal (called the lamina) thereby reducing compression on vital and sensitive neural elements within the spinal canal. Decompressive laminectomy is used to treat spinal stenosis or narrowing of the spinal canal, either due to congenital differences in the size of the bony canal or due to old age and the ravages of disc degeneration and deposition of abnormal bone within the canal.

2. Laminectomy/discectomy is the removal the roof of the spinal canal (laminectomy) and surgically removing disc material, either bulging against neural tissues or extruded out into the bony canal. This procedure is most often used in patients who have clinically significant disc pathology such as disc herniations and is used to relieve sciatica or radicular pain.

3. Laminectomy/foraminotomy: Remember that "ectomy" means removal of something and "otomy" means making a hole or enlarging a hole in bone or other tissue. Therefore, laminectomy means removal of the lamina or roof over the spinal canal so that the surgeon can perform a foraminotomy or widening of the holes on either side of the spinal canal for exit of the nerve roots. This procedure is most often used when there is foraminal stenosis or decrease in the size of the foramina. Decrease in the size of the foramina can result from decrease in disc height when there is severe degeneration of the discs or when the facet joints enlarge to a point that they encroach on the foramen. When discs bulge into the foramina (more than one foramen) in conjunction with one of the above, surgeons will perform a combination procedure called a laminectomy/discectomy/foraminotomy.

4. Spine fusion: Surgeons perform spine fusions to decrease motion across different "motion segments." For our purposes, a motion segment is defined as the vertebral body above, the disc in between and the vertebral body below. Most often spine fusions are performed to stabilize unstable spines. They are also used when patients have discogenic pain. Patents with spinal fusions do best when one motion segment is fused. The outcome typically isn't as good when more than one motion segment is fused.

FAST FACTS REGARDING FUSIONS

• Spinal fusions are posterior, anterior, or a combination of the two, which is sometimes called a "360" fusion.
• Spinal fusions are either performed by using bone from the patient, bone from a cadaver that is treated and sterilized, or with implants. Some fusions are a combination of two procedures.
• Bone grafts are usually taken from the upper pelvis and placed between two motion segments to fuse them.
• Implants are either placed in between the bodies where the discs are, using screws and plates in the lamina or pedicles or both, or on either side of two adjacent bodies.

IMPLANTABLE TECHNOLOGIES FOR THE CONTROL OF BACK AND NECK PAIN

These technologies either provide an electrical signal over the spinal cord or nerves of the back and neck or provide implantable continuous infusion of pain relieving medications directly to the spinal cord where all of the pain signals are being processed. These technologies include spinal cord stimulation (SCS), nerve root stimulation (NRS), motor cortex stimulation of the brain (MCS) or implantable intrathecal therapies, better known as the "morphine pump."

SCS sends an electrical signal over the spinal cord that is processing the patient's pain and is indicated where the pain is neuropathic (nerve related) in nature. The surgeon implants an electrical pulse generator (usually in the upper chest for neck and arm pain or in the upper buttock or abdomen for back and leg pain) which is connected to either one or two "electrode arrays" implanted over the spinal cord in the neck or mid back.

Intrathecal therapies or drug delivery systems (the "morphine pump") is a pump that is implanted under the skin of the abdomen which is connected to a small spaghetti like tube or catheter that is implanted into the cerebrospinal fluid of the spinal canal. Its purpose is to deliver pain relieving medications directly to where they work, at the spinal cord level.

For a greater discussion of these technologies, please go to Implantable Technologies:  Spinal Cord Stimulation and Implantable Drug Delivery Systems.

Remember, always speak to your doctor about your back and ask educated questions about the alternatives for treating your pain. If your doctor recommends a surgical procedure, educate yourself and make an informed decision. The ultimate choice of any intervention to be performed on your body is yours. Educate yourself and choose wisely!