Low Back Pain Overview
Low back pain is one of the main reasons patients visit their physician. Eighty to 90% of people will experience an episode of acute low back pain during their lifetime. There is no consensus among medical professionals however, on the how to distinguish nonspecific back pain from back pain of a discogenic origin.
The classification of low back pain, as described by Moonye (1989) is based on the duration of the episode and can be useful in determining a possible cause. Low back pain was classified into the following categories:
- Acute back pain that lasts less than seven days and is generally related to soft tissue injury (tendon, ligament and fascia) and has the highest potential for spontaneous recovery.
- Subacute back pain that persists longer than seven days, but less than three months and may involve the facet joints.
- Chronic back pain typically lasts longer than three months and is more likely to be disc-related.
Most episodes of back pain improve over time and without surgery. However, certain spinal problems may require surgical intervention. Causes of subacute and chronic back pain often involve significant structural damage and therefore treatment is indicated.
Initial therapy usually includes nonsurgical or conservative treatment. Depending on the cause of the symptoms may include medications (anti-inflammatories, muscle relaxants, oral steroids), physical therapy, massage, acupuncture, and possibly chiropractic treatment. Some patients may require interventional pain management treatments (epidural steroid injections, facet blocks).
Chronic back pain often is further classified into mechanical and back pain associated with sciatica. Mechanical back pain results from degenerative spinal changes, inflammation, or injury to the disc, ligaments or muscles. It typically presents as a pain felt in the lower spine and may radiate into the buttocks and thighs.
Chronic low back pain, accompanied by the loss of bowel or bladder control, or progressive weakness in the lower extremities, indicates a serious problem and requires immediate medical attention.
Sciatica is a term used to collectively describe low back pain that radiates through the left or right buttock into usually one leg sometimes including the foot. Back pain associated with sciatica occurs when the nerve roots that leave the spine are either irritated or pinched. The most common cause of this type of back pain is a ruptured or herniated disc. Rarely is sciatica caused by piriformis syndrome.
Lumbar Herniated Disc
A lumbar herniated disc (intervertebral disc) is a common cause of low back and leg pain (sciatica). The displacement or herniation (rupture) of the disc center presses on the nerves and causes pain, numbness or weakness of the leg.
While disc herniation occurs more often in adults age 50 or older, accidents and trauma affects all age groups. Many factors cause or contribute to the development of a herniated disc such as aging and degenerative disc disease wherein the structural integrity of lumbar discs declines.
Piriformis syndrome has been a controversial diagnosis since its initial description in 1928. Some physicians are skeptical that this condition even exists. Piriformis syndrome is usually caused by neuritis (or inflammation) of the proximal sciatic nerve. The piriformis muscle (located in the buttocks) can either irritate or compress the proximal sciatic nerve due to spasm and/or contracture, and this problem can mimic discogenic sciatica. Piriformis syndrome is also referred to as pseudosciatica, wallet sciatica, and hip socket neuropathy. Pain can be a mild ache, sharp, or excruciating. Some patients experience feelings of burning, tingling, numbness, and / or weakness. A program of specific stretching exercise and corticosteroid injection often helps alleviate the symptoms. Rarely is surgery warranted.
Degenerative Disc Disease (DDD)
Approximately 60% of Americans over age 65 are affected by osteoarthritis, which is the main cause of degenerative disc disease (DDD). By the year 2050, it is estimated that more than 50% of individuals in western European countries over age 65 will be affected.
Aging involves all of the spine’s structures and there are many diseases and conditions that cause or contribute to back pain. Aging of the spine’s structural components may be related to hereditarily-predetermined cell vitality, tissue exposure to heavy mechanical forces during life, or just everyday wear and tear on spinal discs – the back’s shock absorbers – and may eventually cause deterioration.
DDD is a gradual process that usually begins with cracks and tears in the annulus, followed by arthritis in the facet joints, and / or spondylolisthesis, intervertebral disc herniation, development of bone spurs (osteophytes), and collapse of one or more spinal segments.
Collapse of a spinal segment may help relieve pain in some patients. The body’s natural response is to make bone, which stops movement by fusing the segment.
Arthritis of the Facet Joints
Arthritis of the spine (osteoarthritis) can affect the facet joints. The facet joints are located between and behind adjacent vertebrae. Similar to other joints in the body, the facet joints enable spinal extension, flexion, and rotation. Cartilage coats and helps to lubricate moving joint surfaces.
Such degeneration can cause loss of cartilage or joint hypertrophy – enlargement of the joint. Common symptoms include joint stiffness and pain.
Spondylolisthesis occurs when one vertebral body slips forward on the adjacent vertebrae. It may be congenital (present at birth), develop during childhood, or acquired during adulthood. Causes of acquired spondylolisthesis include physical sports such as weightlifting or gymnastics, accumulated spinal stress (daily wear and tear), and degenerative or age-related changes to the spine that causes stabilizing structures to become weak. Typical symptoms include low back pain, sciatica, muscle spasms, leg weakness, tight hamstring muscles, and / or problems walking.
During the diagnostic process, the slip is graded (from 1 to 5) to classify the degree of the spondylolisthesis. The grade and other factors, such as slip progression, pain and neurological symptoms are considered when deciding treatment.
Lumbar Spinal Stenosis and Neurogenic Claudication
Spinal stenosis refers to narrowing of the spinal canal and may involve the central canal, foramen, or lateral recess. The central canal houses and protects the spinal cord, the foramen are the nerve passageways between the vertebral bodies (foraminal spinal stenosis), and the lateral access is where the lumbar nerve roots exit the spinal column (lateral recess stenosis).
Sometimes spinal stenosis is congenital – meaning it is present at birth. However, the majority of cases are age-related and affect people age 50 and older.
Symptoms can make standing, walking, sitting, and other everyday activities difficult. Symptoms typically include:
- Radiculopathy (foraminal stenosis)
- Neurogenic claudication (central canal stenosis)
Failed Back Surgery Syndrome (FBSS)
A patient, whose condition does not improve after spine surgery or who develops new symptoms after initial “successful” surgery may be found to suffer from Failed Back Surgery Syndrome (FBSS). The incidence of FBSS is estimated to be as high as 40% and multiple factors may cause or contribute the development of this complex syndrome.
Possible Causes of FBSS
Possible causes include, but are not limited to central canal, lateral recess or neuroforaminal stenosis, recurrent disc herniation, spondylolisthesis, epidural fibrosis (i.e. formation of scar tissue near a nerve root), arachnoiditis (inflammation / irritation of the spinal cord’s arachnoid membrane), other musculoskeletal or neuropathic pain syndromes, and psychological disorders.
Treatment of FBSS
Treatment of failed back surgery syndrome requires careful consideration with clear and reasonable goals in mind. Neurosurgeons at Boulder Neurosurgical & Spine Associates (BNA) believe that surgery is not always the best treatment for all patients. Our therapeutic approach to treatment of structural and nonstructural spine problems in a patient who has FBSS varies.
A structural cause is clearly identified before surgical intervention can be considered. The type of surgical intervention (i.e. decompression, fusion) is recommended based on the individual patient to specifically treat the underlying cause of failed back surgery syndrome.
If FBSS is related to a nonstructural problem, appropriate treatment may involve a functional solution such as spinal cord stimulation (SCS).
In addition to the patient’s medical history, physical and neurological examination, diagnostic tests may be necessary. Tests may include x-ray, CT scan (Computed Tomography), MRI (Magnetic Resonance Imaging), bone scan, Electromyography (EMG), and / or diagnostic injections.
X-rays (or radiographs) help to identify a bone-related problem, such as a fracture. MRI provides a highly detailed rendering of spinal anatomy and is performed if disc, ligament, spinal cord or nerve root involvement is suspected.
If back pain is considered to be discogenic – caused by an intervertebral disc, discography (discogram) may be recommended. Indications for discography include a protruding, herniated, fixated disc, or for surgical planning of lumbar fusion or artificial disc replacement.
Discography is an invasive procedure that involves injection of a radiographic contrast medium (dye) into the nucleus of a disc. Sometimes discography replicates pain or symptoms (provocative discography) or helps to rule out a disc-related problem. In addition, discography can be useful to evaluate discs adjacent to previously fused lumbar segments. Lumbar discography is contraindicated in patients with a calcified disc herniation and / or severe degenerative facet disease.
Opinions about the indications for and results provided by discography are a controversial topic among some physicians. This controversy may stem from past technological limitations. However, it should be remembered that any diagnostic test, including discography, can produce a false-positive and false-negative result. Modern advancements in fluoroscopic guidance improve needle placement, accuracy of intranuclear injections, and requires less contrast. These developments have led to discography becoming a more sensitive and specific diagnostic tool to evaluate intervertebral discs.
Treatments and Technology
Conservative Spine Care
Patients with spine-related problems require comprehensive care that considers all of the possibilities, variables, and provides the most complete array of treatment options.
The symptoms and causes of spinal conditions vary and can be challenging to diagnose. Spinal osteoarthritis, spondylosis, vertebral compression fracture, spinal stenosis, and disc herniation are just some of the disorders that cause or contribute to low back pain. Many of these structural problems are found on x-ray and in MRI studies of adult patients without symptoms and the frequency of such findings increases with age.
The neurosurgeons are the only specialists that are trained to treat the entire spine (its bony components, the spinal cord and nerves) and have the expertise necessary to diagnose and treat all common and complex spinal disorders. Our skill and extensive experience in spine care has taught us that a thorough physical, neurological and diagnostic evaluation is vital. BNA’s comprehensive treatment plan emphasizes nonoperative management first to avoid or postpone surgery if possible. Nonsurgical conservative treatment usually includes medications, injections, and physical therapy. We believe an organized program of stretching, core muscle strengthening, and other therapies can lead to substantial improvement. When these do not work, interventional therapies could help to reduce inflammation and swelling of the nerves, leading to pain relief.
If conservative treatment is not effective, surgery is considered. Boulder Neurosurgical & Spine Associates provides the most extensive range of surgical procedures and care in the region.
Today, microdiscectomy is one of the most common lumbar surgical procedures performed to remove a herniated disc. Microdiscectomy involves a small incision at the appropriate lumbar level and use of an operating microscope. Using microscopic magnification, a small opening in the spine’s bony lamina, laminotomy, is made and the disc is removed using ultramodern microsurgical techniques.
Please watch an animation, which describes a percutaneous disc removal procedure
When appropriate, Boulder Neurosurgical Associates’ neurosurgeons may use laser technology to complete the microdiscectomy. Click this link to read about clinical outcomes achieved with new breakthrough laser technology.
Laminectomy is a procedure that is commonly performed to treat lumbar spinal stenosis. It involves removing the spinous process (bony projection from back of the vertebral body), lamina (bony covering the spinal canal), and part of the facet joints.
Please watch an animation, which describes a lumbar laminectomy procedure
Laminectomy may be combined with another procedure, foraminotomy.
Often, laminectomy and foraminotomy can be performed using minimally invasive surgical techniques. The neurosurgeons at Boulder Neurosurgical & Spine Associates emphasize the minimally invasive approach and use of the operating microscope to enhance visualization of the spine’s anatomy. This treatment is very effective for spinal stenosis.
Foraminotomy involves decompressing lumbar spinal nerve roots by removing tissue and enlarging the size of the foramen. This procedure is performed to treat foraminal stenosis. A foraminotomy may be combined with discectomy or laminectomy, all of which may be performed using minimally invasive techniques.
Lumbar fusion is easier and safer than ever before.
Lumbar fusion is one of the most common surgical spine procedures. It can effectively treat many low back conditions, including degenerative disc disease, which affects about 30% percent of people over age 30.
Spinal fusion surgery is a common treatment for spinal disorders such as spondylolisthesis with instability, scoliosis or severe disc degeneration. Spinal fusion is performed to join (fuse) one or more vertebrae to stabilize the spine and reduce pain. Fusion often involves the use of instrumentation (i.e. screws, rods, interbody devices) and bone graft. Examples of spinal fusion appear below (Figure 1 A, B).
Figure 1A-B. Postoperative x-rays anterior-posterior (A) and lateral (B) views demonstrate good pedicle screw placement and fusion at the patient’s six month follow-up.
Open Anterior Posterior Approach
The vast majority of lumbar fusions are performed using the anterior-posterior approach, which in our opinion, is unnecessary in most cases. For the anterior-posterior approach, a general surgeon makes a deep three-inch abdominal incision and moves the organs around so the spine surgeon can remove the disc(s) from the lumbar region in the spine and replace them with bone graft(s). The spine surgeon then makes a five-inch incision in the back to access the spine and introduces instrumentation. The procedure can take up to ten hours and requires an average seven days of hospitalization. This complex reconstructive procedure exposes patients to major surgical access, up to ten hours of surgery, unnecessary blood loss, long hospital stays, considerable postoperative pain and prolonged recovery time.
Transforaminal Lumbar Interbody Fusion (TLIF)
The TLIF technique is a modification of a similar surgical procedure called Posterior Lumbar Interbody Fusion (PLIF). Transforaminal lumbar interbody fusion allows for a more lateral, one-sided approach, with direct access to the intervertebral foraminal area without violating the anatomical integrity of the spine’s neural elements.
Please watch an animation, which describes a transforaminal lumbar interbody fusion (TLIF) procedure
Performed correctly, TLIF requires less retraction of nerve root(s) and the thecal sac (cauda equina; the tail end of the spinal cord). The procedure also offers the benefit of circumferential fusion and restoration or maintenance of lumbar lordosis (inward spinal curve). While an open anterior posterior approach can be performed for circumferential fusion, TLIF is less invasive and simultaneously allows for neural decompression and relief of radicular pain.
At Boulder Neurosurgical Associates’ (BNA) we have innovated the way spinal lumbar fusions are performed to reduce associated risks, including postoperative pain and long recovery times (Click here to download PDF article about TLIF).
Minimally Invasive Spine Surgery
BNA spine surgeons were the first in the area to offer lumbar fusion performed as a minimally invasive surgery. Minimally invasive surgical procedures represent a significant forward leap in the treatment of chronic lumbar pain.
At Boulder Neurosurgical & Spine Associates, most surgeries are performed using a minimally invasive approach. Minimally invasive spine surgery involves several small incisions of 0.5 inch to 1.5 inches to access the patient’s spine. A small tube is passed through muscle tissue followed by cannulas of increasing size (quarter-size diameter) to separate muscles and tissue. Through the cannula, disc and / or other tissues are removed.
A special spacer made from human bone or PEEK (polyetheretherketone) is inserted with bone morphogenetic protein to promote fusion. A rod and screws are passed through the cannula and implanted to stabilize the spine.
Please watch an animation, which describes a minimally invasive transforaminal lumbar interbody fusion (TLIF) procedure
A minimally invasive procedure benefits the patient in many ways; less blood loss, shortened hospital stay, quicker recovery. Comparing similar procedures performed minimally invasively versus the anterior posterior open approach, benefits include:
- Average operative time is two hours
- Average blood loss is three times less
- Average hospital stay is just two days
Click here to learn more about minimally invasive approach or BNA research.
Aspen™ Spinous Process Fusion Plate
Aspen™ is a new minimally invasive Spinous Process Fusion Plate (SPFP). It provides single- or multiple-level fusion without rod and screw technology. SPFP is less invasive than pedicle screw fixation because it requires a smaller incision and no additional lateral exposure. Aspen is very easy to implant and does not require fluoroscopic guidance (real time x-ray). There is also no risk for neural injury.
Aspen™ Spinous Process Fixation System. X-rays demonstrate the Aspen device with unilateral pedicle screw placement.
Extreme Lateral Interbody Fusion (XLIF)
XLIF is a minimally invasive procedure that uses a lateral retroperitoneal approach (from the side through the abdominal wall). The procedure affords the surgeon greater visibility, minimizes soft tissue damage, and reduces patient risk.
Please watch an animation, which describes the XLIF procedure
XLIF is used to treat spondylolisthesis, recurrent disc herniations, foraminal stenosis, degenerative disc disease, degenerative scoliosis, and pseudoarthrosis (i.e. failed fusion).
The XLIF procedure provides relief to patients who cannot tolerate a larger, open back surgery because of the increased risks of longer anesthesia time, blood loss, hospitalization, and recovery. It is also a less invasive alternative for patients who have lived with back or leg pain through years of various failed treatments, including steroid injections, physical therapy, and pain medication.
The XLIF procedure includes the use of NeuroVision®, a technologically advanced nerve monitoring system (EMG), which allows the surgeon to have accurate, reproducible, real-time feedback about nerve health, location, and function, reducing the incidence of nerve injury during surgery. The NeuroVision System has been used successfully in over 70,000 spinal surgeries
Axial Lumbar Interbody Fusion (AxiaLIF)
AxialLIF™ is a minimally invasive fusion option that is suitable to treat select spine patients. During an AxiaLIF procedure, the neurosurgeon accesses the L5-S1 area through the sacral spine. This preserves the annulus and ligaments and helps reduce postoperative complications.
Dynamic Stabilization Devices (DSD)
Dynamic stabilization devices are one of the newest additions to the modern spine surgeon’s armamentaria. DSDs include posterior interspinous process and pedicle-based dynamic rod devices. The devices (e.g. Wallis® Dynamic Posterior Stabilization System, Dynesys® Dynamic Stabilization System, X-STOP® Spacer, Coflex® Dynamic Interspinous Stabilization Device, DIAM™ Spinal Stabilization System) are used to treat symptomatic lumbar (low back) degenerative disc disease.
These devices offer a less invasive approach and generally leave the intervertebral disc intact, therefore preserving the natural anatomy and motion of the spinal segment while limiting excessive motion. In theory, dynamic stabilization devices may prevent initial progression of degenerative disc disease when used alone or in conjunction with traditional decompression and fusion procedures. In the near future, DSDs may fill the gap between conservative treatment and more aggressive, irreversible surgeries.
Some authors have opined that clinical outcomes for dynamic stabilization systems are comparable to fusion. In light of the high incidence of reoperation of the lumbar spine, DSDs provide an attractive option for some patients to consider.
X-Stop spacer is one of the dynamic stabilization devices that is currently approved for clinical use.
Other devices are available through U. S. Food and Drug Administration-controlled clinical trials.
Figure. X-STOP® Spacer
The X-STOP® Spacer is a lumbar interspinous process distraction device used to treat low back spinal stenosis. X-STOP helps to preserve the functional spinal unit, relieves nerve root compression (impingement) and therefore helps to reduce symptoms. X-STOP is indicated for patients with mild to moderate lumbar spinal stenosis symptoms and especially for patients who experience symptom relief during spinal flexion.
The X-STOP procedure can be performed under local anesthesia in less than an hour with minimal blood loss. It is especially suitable for patients who cannot tolerate general anesthesia.
There is minimal risk of systemic or local complications and little risk of neurological injury. Future treatment options are not compromised.
Total Disc Replacement (TDR): Lumbar Artificial Discs
Artificial discs are designed to replace a damaged intervertebral disc. As the name implies, artificial discs are similar to normal human discs in the neck and low back.
Total disc replacement surgery is considered an alternative to spinal fusion in select patients. Spinal fusion fuses or permanently joins two (or more) vertebral bodies and eliminates movement at that level. An artificial disc works differently – it allows movement by mimicking the properties of a human disc. In theory, disc replacement protects other discs by sharing the stress during movement.
There are many different artificial disc designs. Implant composition includes hard and soft materials.
- Hard: metal, such as stainless steel
- Soft: nonmetal, such as polyethylene
Charité® Lumbar Artificial Disc. Model of the disc and x-rays; anterior posterior and lateral views.
ProDisc-L Artificial Disc. Model of the device and x-rays; flexion / extension views. .
Since artificial discs are not indicated to treat all spinal disorders or patients, evaluation by a spinal surgeon skilled in the use of artificial discs is essential. If an artificial disc is a good choice for you, your neurosurgeon will explain the type of device to be implanted. Along with information about the artificial disc, you will learn about the benefits and risks of the device and procedure.
Surgeons at Boulder Neurosurgical & Spine Associates (BNA) use the latest spine technologies and believe artificial discs benefit carefully selected patients. If you have questions, please talk to your surgeon to find out if disc replacement is appropriate to treat your spinal disorder.
Click this link to read more about lumbar artificial discs or read the papers (Part 1 PDF and Part 2 PDF) on lumbar artificial discs published by BNA physicians.
Spinal Cord and Nerve Monitoring
For most patients with degenerative or traumatic conditions, tumors, infections, or vascular malformations of the spinal cord, Boulder Neurosurgical & Spine Associates (BNA) uses the services of intraoperative neuromonitoring (IOM) specialists. BNA surgeons were instrumental in bringing such technology to the region and actually founded the company that has since then gone on to impact the care of thousands of patients. The sensory and motor nerves, or muscle groups are monitored to ensure that neural tissues at risk are not damaged during the surgery.
Different neurophysiological tests are performed in real-time during surgery allowing the surgeon to carefully monitor the selected region(s) of the spine. Neurophysiological modalities are selected depending on the region of the spine and condition. Sensory and motor pathways are monitored if there is a risk of spinal cord injury.
Triggered Electromyography is performed to test pedicle screw placement where nerve roots are at risk. This adds safety to spinal surgeries and allows BNA surgeons to have as much information as possible during surgery. The surgeon identifies patients that may benefit from this specialized procedure and always provides the safest possible surgical management.
It is important to remember that this added information does not guarantee the procedure’s success or that it will be without complications, but in conjunction to the other techniques, such as intraoperative image guidance and advanced minimally invasive technology, it significantly increases the margin of safety.