Spinal Fusion - Advanced Alternatives

INTRODUCTION

Surgical fusion of the cervical or lumbar spine is a common orthopedic or neuro-surgical procedure. Spinal fusion has benefitted many patients, and affords pain relief to many. Patients with spinal instability or severe scoliosis may need a spinal fusion to prevent further neurologic injury and to restore strength and function to the spine.

INDICATIONS FOR SPINAL FUSION

Common indications for surgical fusion include scoliosis, or curvature of the spine, spondylolisthesis, or slippage of the spine, and severe degenerative arthritis. Other indications may include chronic back pain resulting from disease or injury involving the vertebral discs or spinal facet joints.

THE SURGICAL TECHNIQUE

Spinal fusion is the surgical technique whereby bone is harvested from a site such as the hip, and transplanted to the spine. The appropriate spinal articular joints of the spine are then destroyed; the harvested bone is then packed into the joint space, thereby providing a matrix upon which new bone grows. As the healing process takes place the new bone ablates the joint, thereby preventing motion of the involved joint. The intended result is to provide stability to the spine.

RISKS OF THE PROCEDURE

The surgical patient faces multiple risks of infection, neurologic injury, and anesthesia risk. The greatest risk may well be the risk of further surgical intervention to correct incomplete fusion, failure of the procedure, and broken hardware.

THE INTENDED SURGICAL RESULT

A solid fusion over the affected segment may prevent pain by preventing segmental spinal movement. For many patients, this operation is of tremendous benefit. Scoliosis may be corrected, pressure on nerves may be relieved, and pain may be reduced.

THE UNINTENDED SURGICAL RESULTS

Unfortunately, however, for many, the operation does not help the pain, or may in fact result in even worsened pain.

ALTERNATIVES TO SURGICAL FUSION

RADIO-FREQUENCY NEUROABLATION

INTRODUCTION: First used in the 1950's, radiofrequency neuroablation (RF) is a safe and effective tool that utilizes small needles which are inserted through the skin, and placed very near the structure that is causing the pain, or it is placed beside the small sensory nerves that serve the pain-causing structure.

RF TECHNIQUE: Using fluoroscopy, which is an X-ray technique that permits rapid interpretation of the needle location, the special needles are set in place, and an electric current is allowed to heat the needle tip. The intended sensory nerve is thereby burned, and pain relief can be expected in 80-90% of patients thus treated.

ANESTHESIA: RF is performed under local anesthesia, and using small amounts of I.V. sedation. Patients do not require general anesthesia, and the anesthesia risks are thereby avoided. The procedure can be done as an outpatient or in a properly equipped physician's office.

INDICATIONS: The safe application of RF techniques have expanded in recent years to effectively treat many conditions that previously were only helped with extensive and risky surgery.

Specific treatments have been devised for the treatment of pain resulting from facet joints arthritis, which is the most common arthritis of the spine. Other types of disorder that may be treated with radio-frequency neuroablation include nerve root pinch resulting from posterior element degeneration, annulus fibrosis of the vertebral discs and the arthritis of the Sacro-iliac joint.

Excellent success has been found in the treatment of facet joint pain and in disc pain. Thus far, many patients have been treated successfully with R-F neuroablation. Through the use of RF, many patients were able to avoid the greater risks associated with spinal fusion. The RF procedure for these problems is relatively safe, effective and is much lower in complication rate than is surgery.

CONSIDERATIONS

DIAGNOSIS: Perhaps the most important consideration prior to surgery, or any medical treatment is ensuring a precise structural diagnosis. It is an unfortunate fact of life that incomplete or incorrect diagnosis results in surgical decisions that may result in worsening of a situation.

The presence of pathology involving a disc, such as "bulging disc," "herniated disc," and "slippage of the spine," does not necessarily mean that the identified problem is causing a person's pain. Fully 1/3 of all adults walking around the local mall, asymptomatic, that is, not complaining of pain, WILL DEMONSTRATE A HERNIATED DISC ON MRI SCAN!! Should one of these unfortunate people pull a muscle, which can often cause pain to go down an extremity, "pinched nerve" is often diagnosed, and unnecessary surgery ensues.

At the core of good medicine is the need for accurate diagnosis and precise intervention. MRI CT Scan and myelogram give excellent anatomic pictures of the spine, but they cannot tell us what causes pain in a particular individual. Abnormal radiological appearances can be a trap for the unwary medical practitioner. The only current method of accurately diagnosing a structural abnormality as the source of pain is to perform a logical, sequential and precise "segmental" diagnosis using temporary anesthetic blocks as a guide.

ELECTRO-DIAGNOSTIC STUDIES: It is common for a patient who suffers from back pain, disc disease, or sciatica to undergo testing such as EMG and Nerve Conduction Studies (NCS) to evaluate the source of pain. Unfortunately, These tests are somewhat insensitive when dealing with the vast majority of back pain problems. It takes a substantial injury to the spinal roots to show up on EMG, and when it does, the information is often sadly incomplete.

Somato-Sensory Evoked Potentials is a newer and far more sensitive diagnostic tool, and if properly administered, provides structural information where the EMG and NCS do not.

MEDICAL WORK-UP: In order to properly identify a source of pain, a diagnostic work-up must be undertaken. In many regards, it is little different than the process that the average individual would do to find out which fuse has blown at their home. When a blown fuse is replace, THE LIGHTS GO BACK ON. In the case of spinal pain, when the source of the pain is located, the PAIN GOES AWAY.

The process of finding the source of the pain, or the "pain generator," is a systematic approach looking at each reasonable level of the spine, taking into consideration the joints, discs, nerves, tendons and ligaments that might be involved. This may be referred to as a segmental work-up.

This segmental workup determines if the problem involves the vertebral discs, posterior facet joints and the spinal nerves. Local anesthetic injections are used to identify possible causes of a person's pain. The local anesthetic temporarily "turns off" the structure, and if the pain is relieved, temporarily, a more permanent solution can be considered.

If a particular structure of the spine is found to cause the pain, then procedures such as Radio-frequency neuroablation, can be used therapeutically to interrupt pain transmission resulting in pain control and in many cases, avoid the considerable risk of surgery.

LIMITATIONS TO RF: RF is probably not the technique of choice to control severe scoliosis or spinal instability. There are a few new interventions that may prevent major surgical operations for these conditions.

SPINAL CORD STIMULATION

There have been many improvements in the treatment of chronic pain. Many patients benefit from a variety of treatment approaches, but there are those patients for whom relief is not so easily achievable. Better understanding of the chemical and physical mechanisms of pain has led to newer, very sophisticated approaches to the relief of pain.

One new therapy that offers potential for relief of intractable pain is SPINAL CORD STIMULATION. Spinal cord stimulation, or SCS, is the technique of electrical stimulation of a precise portion of the spinal cord, with very low energy current, which essentially shuts down the input of pain fibers from a desired portion of the body. The technique provides pain relief, but does not interfere with normal sensation, normal muscular ability, or any other bodily function.

SCS is accomplished using a small wire electrode, or lead, which is passed through the skin, and comes to rest close to the spinal cord, along the segment of the cord that is involved with a patient's pain. One end of the lead rests in what is called the "epidural space," and, the other end is attached to a battery operated signal generator, about the size of an oatmeal cookie. After the SCS lead is placed properly, the signal generator is adjusted to provide a "pattern" of stimulation that provides maximal pain relief for the patient.

Not all patients are candidates for this therapeutic approach, but for those who are, relief can be expected in patients between 70% and 80% of the time.

INDICATIONS FOR SCS TREATMENT

Failed Back Surgery Syndrome

Adhesive Arachnoiditis

Phantom Limb or Stump Pain

Peripheral Neuropathy

Reflex Sympathetic Dystrophy (RSD), Causalgia, and Complex Regional Pain Syndrome (CRPS)

Ischemic Pain

PATIENT SELECTION

Generally, successful outcome is most likely if thoughtful patient selection is carefully observed. Patients do best if most of the pain is experienced in the limbs, if the patient demonstrates minimal psychological difficulty, and if there is no substance abuse.

SCS TECHNIQUE

The SCS procedure is essentially a two-step modality. The first step involves the use of a temporary lead, which is placed through the skin to the targeted level of the spinal cord. The temporary lead exits the skin and is attached to a battery-signal generator which is worn on the belt. The temporary, or trial lead, is used for 3-5 days.

If satisfactory pain relief is obtained, the temporary lead is removed, and a permanent lead is placed at the same location, but the remainder of the lead, and signal generator are implanted under the skin. The signal generator is about the size of a pacemaker battery, which is quite small.

After placement under the skin, and after the bandage is removed, normal activities are possible. Little special care is required for the system, although periodic medical evaluation is a good idea. There are very few special considerations, and many patients return to a more normal, satisfying life.

PLEASE NOTE:
There are remarkably few circumstances where relief of pain is unachievable. The diagnostic skill of the physician is the most important determinant of successful treatment of pain. Judgement, which is the ability to properly decide which of many therapeutic paths to choose, is also important. Without technical skill, or the physical ability to perform a medical procedure, the ability to treat a complicated patient fails.

Before considering any intervention, it is extremely important that the patient makes certain that the physician is properly informed, properly trained, and uses the highest quality equipment.