A. Back pain, with or without radicular symptoms, is one of the most common ailments in our society.
1. In most patients, symptoms respond to nonsurgical management.
2. Treatment modalities include medication, physical therapy, chiropractic care, injections, and radiofrequency ablation, electromyography, and diskography.
3. Physical therapy and chiropractic care are the standards of care for axial back pain or neck pain.
C. Diagnostic studies
1. Diagnostic studies are used to differentiate reasons for pain and to correctly identify pain generators.
2. Many spinal injections serve as both therapeutic and diagnostic agents.
II. Physical Therapy and Chiropractic Care
A. Physical therapy relies on mobilization, stretching, modalities, conditioning exercises, and aerobic training.
1. Spinal mobilization
a. Mobilization is movement within the joint's normal range of motion that does not cause cavitation.
b. It is theorized that this treatment works by release of synovial tissue, stretching of adhesions, endorphin release, and muscle relaxation.
2. Extension-based exercise programs
a. These programs are based on the work of McKenzie.
b. Extension-based exercises are most useful in patients who have pain while sitting or when the spine is in flexion.
c. It is believed that the disk is the major pain generator in these patients and can be unloaded by restoring lumbar lordosis, decreasing mechanical strain on the lumbar spine.
3. Flexion-based exercises
a. These exercises are based on the work of Williams.
b. Historically, flexion-based exercises have been used for all types of spinal disorders, but they are most often used in patients with pain on extension or those with stenosis symptoms.
4. Core strengthening—Abdominal and pelvic floor muscle exercises to condition and strengthen the transverse abdominus, multifidus, and pelvic floor muscles are useful in all lumbar conditions.
5. Modalities—Passive modalities such as ice, heat, whirlpool, and transcutaneous electrical nerve stimulator (TENS unit) therapy are used in the early phases of treatment to decrease pain and spasm.
6. Aerobic training—Low-impact activities such as biking, using an elliptical trainer or stair climbing machine, and swimming may be beneficial by strengthening the core while assisting in weight loss.
B. Chiropractic care
1. Chiropractic care differs from physical therapy in that it relies more heavily on manipulation.
2. Manipulation is defined as a controlled passive force that takes the joint past physiologic motion, causing joint cavitation. The cavitation causes a popping sound known as "cracking a joint."
3. Many studies have compared the results of chiropractic care and physical therapy. It has been concluded that the treatments are equally effective for acute back pain and both give significantly better results than minimal intervention.
4. For chronic back pain and neck pain, the results are less promising.
5. Manipulation is not recommended in patients with cervical spinal stenosis with symptoms of radiculopathy or myelopathy.
1. Physical therapy is the standard of care for axial back pain or neck pain. It may provide at least a short-term benefit in the treatment of axial pain, but its use for radicular symptoms is less well defined.
2. Manipulation may be an efficacious treatment for short-term relief when cervical spinal stenosis, radiculopathy, or myelopathy is not present. It is up to the patient and physician to decide which treatment is appropriate.
A. Role in treatment
1. Medication should play a secondary role in acute spinal pain, because pain can usually be controlled rapidly by physical modalities. When used, medication plays a supplemental, not curative, role.
2. Medication is suitable when recovery is incomplete or pain is severe.
B. Types of medication
a. Acetaminophen is as effective for pain relief as aspirin.
b. It has minimal anti-inflammatory effects.
c. Hepatotoxicity is a side effect at high doses.
2. Nonsteroidal anti-inflammatory medications (NSAIDs)
a. NSAIDs have anti-inflammatory and analgesic effects.
b. Effects are related to the inhibition of prostaglandins by the cyclooxygenase (COX) enzyme.
c. Adverse reactions include nausea, epigastric pain, diarrhea, and ulcer.
d. Renal toxicity is a problem, especially in patients with renal insufficiency.
3. COX-2 inhibitors
a. The efficacy of COX-2 inhibitors is equivalent to that of the older NSAIDs.
b. COX-2 inhibitors have a side chain that prevents them from entering a COX-1 active site.
c. COX-2 inhibitors have fewer gastrointestinal, genitourinary, and platelet function side effects.
d. Recently, they have been associated with an increased risk of cardiac events with long-term use.
4. Opiate analgesics
a. Opiate analgesics are rarely necessary in the treatment of acute pain.
b. They are useful in treating chronic nociceptive pain.
c. Opiate analgesics should be prescribed by a pain management specialist with a written contract and always refilled in person.
d. Addiction occurs in a minority of patients.
5. Muscle relaxants
a. Muscle relaxants include central nervous system (CNS) anxiolytics, hypnotics, and sedatives with CNS effects.
b. Examples are cyclobenzaprine, diazepam, and orphenadrine.
c. Side effects can include depression and drowsiness.
a. Antidepressants are recommended for the treatment of chronic pain only.
b. They work by blocking the reuptake of norepinephrine, serotonin, or dopamine; those that block norepinephrine are the most effective analgesics.
c. Side effects include dry mouth, weight gain, urinary retention, and sexual dysfunction.
a. Anticonvulsants are recommended for neuropathic pain.
b. Side effects include dizziness, ataxia, headaches, and somnolence.
8. Oral corticosteroids
a. Oral corticosteroids are effective for acute radicular pain, but they have no role in the treatment of mechanical spine pain.
b. Oral corticosteroids have significant side effects, including osteonecrosis.
IV. Epidural Steroid Injections
1. Epidural steroid injections (ESIs) have been used
Figure 1. Oblique fluoroscopic view confirms correct needle placement (arrow) under the pedicle in the transforaminal space during a two-level transforaminal ESI.]
Figure 2. Needle placement using the lateral fluoroscopic view during transforaminal ESI.]
Figure 3. Epidurogram showing adequate epiradicular flow at L4-5 during ESI.]
to treat radiculitis or stenosis symptoms since the early 1950s.
2. The options to access the epidural space are translaminar, transforaminal, or caudal.
3. The primary indications for ESI are radicular pain or claudication unrelieved by other medical management.
4. Epidurals are not only therapeutic but can also serve as an important diagnostic study. Nerve compression pain improves with ESI, while somatic or mechanical back pain is usually not affected.
5. ESIs are done in the cervical, thoracic, and lumbar spine.
6. Complications include inadvertent dural puncture (most common with intralaminar ESI), bleeding, intravascular placement, nerve injury, infection, and reaction to corticosteroids. ESI in the cervical area also carries a risk of paralysis and vertebral artery injury.
1. Modern ESI techniques use contrast to guide placement, which decreases the incidence of most complications.
2. Translaminar ESIs are done with special needles and rely on the loss of pressure once the ligamentum flavum is pierced.
3. Transforaminal ESI is performed with the aid of epidurography, which allows visualization of good epidural flow around the pedicle and verification of the position of the exiting nerve root to confirm good needle placement (Figures 1 through 3).
4. ESI can be repeated, but a positive response to the initial injection is important. If relief is transient, further injections should not be attempted. Injections are usually limited to three to four per year so as not to exceed corticosteroid dosing recommendations.
1. Recent studies have attempted to predict the efficacy of ESI. Translaminar ESIs have been shown to be successful in the short term but have little long-term benefit.
2. In contrast, transforaminal ESIs have shown more promise, especially in lateral disk herniations. Some studies have shown relief for up to 3 years in approximately 75% of patients. Transforaminal ESIs may require multiple injection sites, however.
3. Cervical transforaminal epidurals also have shown promising results in recent literature.
V. Facet and Medial Branch Blocks and Radiofrequency Ablation
1. Facet joints are a possible pain generator in the lumbar spine. These joints are innervated by the medial branch of the dorsal ramus after it exits the neuroforamen above and at the level of the facet.
2. A physical finding of facet-related pain relies on pain with extension and rotation.
3. Many studies have researched the best way to diagnose facet-mediated pain, but no clinical or radiographic study can clearly identify the facet joints as the pain generator. As a consequence, it is difficult to recommend these injections be done on patients if there is no way to identify which patients will benefit from the injections.
4. Based on these conclusions, facet injections should be a last resort after all other causes of back pain have been eliminated.
1. Two procedures are performed to diagnose and treat facet-mediated pain—medial branch block (MBB) and facet joint injection (FJI).
a. For MBB, the spinal needle is directed toward the pars (neck of the "Scotty dog") on the oblique fluoroscopic view and the injection is performed.
b. For FJI, the needle is passed into the facet joint and dye is injected. There should be presence of a dumbbell-shaped contrast pattern, and then an anesthetic and steroid can be injected.
c. If there is a positive response to the first injection, a second confirmatory injection is recommended. If sufficient pain relief is obtained, radiofrequency ablation may be recommended.
2. Radiofrequency ablation involves using radiofrequency to ablate the medial branch nerves. Fluoroscopy is used to guide the electrode to the course of the nerve. The electrode then coagulates the nerve, deinnervating the facet joint.
a. This process is usually verified by the use of electromyography (EMG).
b. Relief can last up to 12 months.
VI. Sacroiliac Joint Injections
1. Similar to facet pathology, there is no clinical finding that can be relied on to make the diagnosis of sacroiliac (SI) joint pain. Manual compression, the Patrick test, and a host of other tests have been found to have no diagnostic value.
2. SI joint-related pain is thought to correlate with pain over the posterior superior iliac spine or directly over the SI joint that radiates to the groin or buttock.
3. The indication for SI joint injection is similar to that for treatment for facet joint pain: it is usually done as a last resort, when all other sources of pain have been explored.
4. Some authors advocate radiofrequency neurotomy if SI pain does not respond to SI joint injection.
1. The inferior third of the SI joint is identified on fluoroscopy.
2. A spinal needle is introduced and contrast is used for confirmation of intra-articular placement.
3. Injection of anesthetic and corticosteroid is then performed.
a. EMG is an important diagnostic tool in cervical and lumbar radiculopathy.
b. It can differentiate nerve compression from myopathy, anterior horn cell disease, or peripheral neuropathy.
2. EMG in the diagnosis of radiculopathy
i. EMG is used to evaluate the motor unit at rest for spontaneous muscle activity. When present, such activity indicates membrane instability or neuronal injury.
ii. The next stage of EMG evaluates the motor unit during mild, medium, and full muscle effort.
iii. Occurrence of motor unit dropout can be determined by evaluating duration, amplitude, and phase of the motor unit.
iv. Abnormality in two separate muscles sharing the same nerve root but innervated by different peripheral nerves is suggestive of radiculopathy.
b. Advantages—Because EMG is specific for radiculopathy but MRI lacks specificity for this condition (many asymptomatic patients have positive MRI findings). Positive EMG findings in combination with positive physical examination and MRI results can diagnose radiculopathy reliably.
c. Disadvantages—EMG lacks sensitivity.
i. Because nerve injury can be present for 7 to 10 days before motor unit changes, EMG can be normal.
ii. Additionally, pain fibers are not tested by EMG.
i. EMG is better at ruling in radiculopathy than excluding it.
ii. A negative EMG should not deter a surgeon from diagnosing of radiculopathy if the physical examination and MRI fit a radicular picture with some certainty.
3. EMG in the diagnosis of myelopathy
a. EMG is positive only if ventral gray matter containing α motor neurons is affected.
b. Myelopathy can be differentiated from radiculopathy by the presence of fasciculations indicating upper motor neuron disease.
c. A polyradicular picture may also indicate myelopathy.
B. Nerve conduction velocity studies
1. Nerve conduction velocity (NCV) studies are also useful in differentiating radiculopathy from peripheral nerve compression.
2. NCV studies are normal in radiculopathy and abnormal in peripheral nerve compression.
C. Neurophysiologic monitoring—Several types are commonly used during spinal surgery.
1. Somatosensensory-evoked potentials (SSEPs)
a. SSEPs are cortical or subcortical responses to repetitive stimulation of a mixed peripheral nerve.
b. SSEP testing is not a real-time test because information is averaged for extraction of background noise.
c. Typical stimulation includes the peroneal, posterior tibial, ulnar, and median nerves.
d. SSEP testing gives information on the posterior spinal column; a 50% change in amplitude is cause for more concern than changes in latency.
e. Factors that can cause changes other than neurologic injury include halogenated anesthetics, nitrous oxide, hypothermia, and hypotension.
2. Transcranial electric motor-evoked potentials
a. A stimulus to the motor cortex stimulates the corticospinal tract axons, which synapse with α motor neurons, which innervate muscles.
b. The warning criterion is a decrease in amplitude of 75%.
a. Free-running EMG is used during dynamic phases of surgery to indicate nerve root manipulation or injury.
b. Burst and train responses are most common; sustained train responses are the most concerning.
Figure 4. MRI and diskography in the diagnosis of spinal pain. A, T2-weighted MRI demonstrates degenerative disk disease at L4-5. Arrow points to area of high intensity. B, Lateral diskography film obtained during injection. Diskography produced concordant pain with a degenerative annular tear dye pattern.]
c. Stimulus-evoked EMG is useful during static phases of surgery such as pedicle screw testing. Low-current depolarization (less than 7 mA) is cause for concern.
a. The origin of most low back discomfort is believed to be discogenic. Most loads in the lumbar spine are supported by the anterior column.
b. Torn nerve endings or injured inner anulus fibers are possible sources of pain.
c. Facet joints are believed to play a minor role in pain generation.
d. To differentiate the pain generator, some physicians rely on diskography.
e. Diskography entails pressurizing the disk with non-noxious fluid in attempts to stimulate nerve endings in injured disks.
f. A positive diskogram at one level with a negative control may indicate that the patient is a candidate for fusion or arthroplasty.
a. Diskography involves placing spinal needles into the nucleus of the disks under fluoroscopic guidance. A normal-looking disk on MRI is used as a control while suspected injured or degenerated disks are tested (Figure 4, A).
b. A few milliliters of contrast dye are injected into the disk, and pain response is recorded. The dye pattern is also recorded to diagnose the presence of annular tear if the dye leaves the center nucleus (Figure 4, B).
c. Newer techniques of diskography are being developed.
i. These techniques involve the use of anesthetic mixed with the contrast to relieve pain shortly after injection.
ii. A recent technique involving placing a catheter in the disks and adding anesthetic to each individual disk at different times has also been developed. Initial results are promising.
a. The utility of diskography remains controversial. Studies exist that both support and discredit diskography as a diagnostic test for surgical success.
b. The addition of the anesthetic component may produce a better test than the conventional diskogram.
c. Currently, concordance of pain, a negative control, dye pattern, and the patient's overall pain response is used to interpret the test.
Top Testing Facts
1. Spinal manipulation is defined as a controlled passive force that takes the joint past physiologic motion, causing joint cavitation.
2. Spinal manipulation is at least as effective for short-term relief of acute back pain as other nonsurgical treatment, but it is not recommended in radiculopathy or myelopathy.
3. Physical therapy is based on mobilization and flexionor extension-based exercises.
4. Transforaminal ESIs have shown efficacy, especially in lateral disk herniations.
5. Facet joints are innervated by the medial branch of the dorsal ramus after it exits the neuroforamen above and at the level of the facet.
6. Manual compression, the Patrick test, and a host of other tests have been found to have no diagnostic value in the diagnosis of SI pain.
7. EMG is used to evaluate the motor unit at rest for spontaneous muscle activity, which, when present, indicates membrane instability or neuronal injury.
8. Abnormality on EMG in two separate muscles sharing the same nerve root but innervated by different peripheral nerves is suggestive of radiculopathy.
9. EMG lacks sensitivity but is specific in the diagnosis of radiculopathy.
10. Diskography entails pressurizing the disk with a non-noxious fluid in an attempt to stimulate nerve endings in injured disks.
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