CHAPTER SYNOPSIS:
The complete understanding of axial neck pain remains elusive. Its causes are multifactorial, and the commonly prescribed treatments are largely nonspecific. Surgical intervention remains controversial but potentially viable. Its overall modest outcomes success is predicated on the lack of a clear understanding of the source of pain. This chapter provides an update on the options and limitations of nonoperative therapies, spinal injection therapies, and surgical intervention.
IMPORTANT POINTS:
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It largely remains unknown whether an optimal nonoperative therapy exists, including its efficacy, timing, duration, and cost-effectiveness, in providing symptom relief in the treatment of axial neck pain.
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Indications for surgery include disabling neck pain not alleviated by nonoperative therapies, strict adherence to selecting the right patient, selecting the right level(s), and selecting the right operation.
Axial neck pain affects 10% of the general population at any given time. About 15% of the population experiences persistent or chronic neck pain, with 5% becoming disabled. Although neck pain has been regarded as self-limiting and benign, it continues to consume a substantial proportion of health care resources.
Neck pain is considered a multifactorial disorder with many possible causative factors. Structures known capable to transmit pain include intervertebral discs, nerve root dura, facet joints, fascia, and muscles. No historical features and examination findings exist that can reliably implicate a specific anatomic structure as a source to axial neck pain. Imaging studies have also been unreliable in identifying the source of axial neck pain. Similarly, anatomic provocation studies have demonstrated patterns of pain referral with similar character and distribution. The majority of patients with neck pain are hence readily categorized as having a “nonspecific” problem.
Although uncommon, specific and sometimes serious causes of neck pain require special attention. Radiculopathy is commonly associated with neck pain as the dominant complaint, particularly if the nerve root compressive lesion occurs at an upper cervical level, C3 or C4. Potentially serious problems include myelopathy, intraspinal or extraspinal tumor, fracture, or infection. Hence, a careful and skilled examination with cognizance of the presence of any ominous, albeit sometimes subtle, red flag findings is critical before making the recommendation of a nonoperative treatment program for a patient with axial neck pain.
NONOPERATIVE MANAGEMENT
In the majority of cases of axial neck pain, noninvasive treatment modalities are the mainstay of care. In a long-term study with a 5-year average follow-up, Gore et al. report 68% of patients treated without surgery experienced symptom improvement, with 43% being pain free. Persistent moderate-to-severe pain was reported in 32% of the patients. Severe initial symptoms and specific event-related injury correlated with unsatisfactory outcome, whereas the presence of degenerative changes, sagittal diameter of the spinal canal, degree of cervical lordosis, and any interval change of these measures were not of any value in predicting outcome.
Generally, nonoperative measures are initially recommended by the primary care physician. It largely remains unknown whether an optimal treatment measure exists, including its efficacy, timing, duration, and cost-effectiveness in providing symptom relief in the treatment of neck pain irrespective of specific cause. The many treatments available also carry trade-offs between potential benefit and harmful effects, with no treatment clearly identified as safer than any other. Fortunately, most patients do experience symptom improvement with only rare harmful effect, regardless of the therapy selected.
Advice and Patient Education
When first presenting with benign nonspecific neck pain, most patients are concerned with whether they should avoid certain activities, and whether their underlying problem is going to worsen. It is now generally accepted that no increased risk for injury or worsening of pathology exists regardless of the patient’s normal routine activity, including simple exercising, and reassurance is a key factor in initiating a treatment program. Practical advice should consist of having the patient avoid the pain-provoking activity whereas maintaining a normal level of nonvigorous activity during a period of symptom exacerbation. A short period of rest may be helpful, but strict bed rest should be discouraged. Patient education should emphasize self-care, proper posture and body mechanics, and judicious and progressive exercise. In a randomized, controlled trial (RCT), Klaber et al. found that advice toward self-care alone was as effective when compared with physical therapy consisting of simple advice, physical modalities, mobilization, and exercise.
Medical Therapy
Most common medications used in the treatment of axial neck pain are over-the-counter analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), narcotic analgesics, muscle relaxants, and antidepressants. Despite their ubiquitous use, a paucity of clinical trials remains on the efficacy and comparative safety of any of these medications in patients with axial neck pain.
Over-the-Counter Analgesics
Ideally, acetaminophen or acetylsalicylic acid should be tried as a first-line course of pharmacotherapy in mild-to-moderate neck pain, given their relatively safe side-effect profiles compared with NSAIDs and opiates. Many patients, however, find these medications inadequate in providing pain relief and require a second-line therapy. Indeed, a study comparing acetaminophen with diclofenac in the treatment of hip or knee pain found acetaminophen as an inferior treatment. Although the side effects are uncommon, they are not without consequence including gastric ulcer and dyspepsia.
Nonsteroidal Anti-inflammatory Drugs
If inflammation is the true underlying mechanism of a person’s neck pain, regardless of the structural pathology, NSAIDs, with their analgesic and anti-inflammatory effect, should provide benefit. Indeed, NSAIDs are the most common line of drug therapy advised despite a lack of data demonstrating superior efficacy over other forms of pharmacotherapy in treating neck pain. This contrasts with extensive evidence supportive for the use of NSAIDs for acute and chronic low back pain (LBP). A meta-analysis of NSAID efficacy in patients with acute LBP has demonstrated greater short-term effect as compared with placebo. Evidence of greater efficacy of NSAIDs in chronic LBP, however, was not found.
No strong data indicate a substantial difference in efficacy between the classes of NSAIDs. Anecdotally, variation in response commonly occurs with the different classes of NSAIDs. Therefore, if a lack of effect is seen with one NSAID, another one from a different class could be tried.
If the patient responds positively to an NSAID, it becomes imperative to monitor for adverse gastrointestinal, renal, or cardiovascular effects. Patients at risk, or those demonstrating an adverse effect, should have their NSAID discontinued and an alternative therapy considered.
Opiates
Currently, no available study is determining the efficacy of opiates in the management of chronic neck pain. Nevertheless, a few recent studies on the use of opioids in other pain disorders are worth mentioning. A double-blind, placebo-controlled study of oxycodone for treating osteoarthritis found it superior in providing pain relief and improved sleep, and guidelines support their use in such patients. In contrast, a recent systematic review found no conclusive evidence that opiates are effective in the long-term (>16 weeks) treatment of chronic back pain. Bartleson has found no additional improvement in function or rehabilitation in patients with LBP taking opiates. A large epidemiologic study in Denmark found that patients treated with opiates for chronic pain had greater levels of pain, poor self-rated health, increased levels of unemployment, lack of leisure-time physical activity, greater use of health care, and a lesser quality of life. Also, an inherent loss of efficacy occurs at the same time as increasing side effects over time.
From a practical view for patients with moderate-to-severe pain, judicious and short-term use of opiates may be necessary. Patients should first demonstrate a lack of response to nonopiate therapy and evidence of significant underlying cervical spondylosis. If used, they should be prescribed with a strict time frame and combined with a progressive, function-oriented rehabilitation program. If improvement with opiates is not observed within 2 to 3 weeks, they should be discontinued.
Muscle Relaxants
Spasms of the pericervical musculature are commonly associated with an acute exacerbation of axial neck pain, regardless of the underlying causative factor. No randomized studies have been reported on the use of muscle relaxants for axial neck pain. In patients with LBP, they have been reported to decrease muscle spasm and tenderness, improve range of motion, improve activities of daily living, improve pain-disturbed sleep, and have an additive effect of symptom improvement when combined with an NSAID. These effects are greatest within the first week after initiating their use with a waning efficacy thereafter. They do not hasten a more rapid functional recovery; commonly cause adverse effects, including sedation, dry mouth, or both; and carry a risk for physical dependence.
If considered, muscle relaxants are best used in the presence of palpable muscle spasm and as a short-term adjunct to an analgesic. They should be limited to no more than 2 to 4 weeks.
Antidepressants
No studies are specific to the treatment of neck pain demonstrating efficacy of antidepressants. Studies of antidepressants on chronic LBP have demonstrated a modest improvement in pain severity in comparison with placebo, but insignificant differences in functional status. Common side effects include dry mouth, dizziness, drowsiness, weight gain, sexual dysfunction, and cardiac conduction abnormalities.
Antidepressants should be considered as an adjuvant in the medical treatment of neck pain. Application of them is best in patients who demonstrate a depressive component to their pain problem or as an aid in patients with sleep difficulty, or both.
Physical Therapy
Therapeutic Exercise
Therapeutic exercises involve the active treatment of physical dysfunction or injury with the intention to restore normal function. Therapeutic exercises used by physical therapists include cervicothoracic stabilization and strengthening, stretching, and relaxation techniques. Dynamic endurance and isometric strength training in women with chronic or recurrent neck pain yielded better pain and disability outcomes at 1-year follow-up compared with a control group given advice on exercise. The long-term benefits can be maintained by continuing training as infrequently as twice a week. Stretching and aerobic exercises alone proved to be a much less effective form of training than strength training. In another study with long-term follow-up (1–2 years), strengthening exercises alone or in combination with spinal manipulation therapy resulted in significantly better pain and disability outcomes than the use of manipulation alone.
Physical Modalities
A plethora of adjunctive physical modalities are commonly used by the physical therapist, including diathermy, ultrasound, transcutaneous electrical nerve stimulation, electrical muscle stimulation, hydrotherapy, and traction. Despite their accepted and ubiquitous use, a recent best-evidence synthesis of the literature (1980–2006) examining such passive modalities alone or in combination with medications did not demonstrate improved pain and disability outcomes in the treatment of subacute or chronic neck pain when compared with other modalities, usual care from a general practitioner, mobilization, or sham intervention.
Manual Therapies
Manual therapy consists of hands-on mobilization of the neck within its normal range of motion. A best-evidence review of four RCTS has consistently demonstrated that mobilization or exercise sessions alone or in combination with analgesics had better pain and disability outcomes in the short term (4–13 weeks) in subjects with subacute or chronic neck pain when compared with usual care provided by a general practitioner, pain medications, or self-care advice. Differences between the groups, however, lose significance at longer-term follow-up (3–12 months). In the same review, four other RCTs were evaluated that showed cervical spine manipulation alone or with advice and home exercises not associated with greater pain or disability reduction in the short or long term when compared with mobilization with or without traction, strengthening exercises, or manipulation.
In a recent systematic review of 13 RCTs, neck exercises with the addition of cervical mobilization or manipulation, or both, as a multimodal application has proved beneficial for pain relief, functional improvement, and global perceived effect for subacute and chronic mechanical neck disorders. The evidence did not favor mobilization, manipulation, or both without exercise. In addition, exercise alone provided less patient satisfaction than exercise plus manipulation.
Soft Collars
Using a soft collar with the neck in mild flexion may help alleviate acute pain and muscle spasm. It may also provide a feeling of security while the patient naturally resolves his or her symptoms. In a recent best-evidence synthesis, soft collars were found to have either no or less benefit when compared with active therapies, rest, or usual care prescribed by a primary care physician.
Spinal Injections
Spinal injections are also frequently tried as a form of minimally invasive therapy for axial neck pain. Structures injected include facet joints, nerve roots via the neuroforamen, and the epidural space via interlaminar placement. Pain relief lasting longer than the known, relatively short duration of action of local anesthetics and steroids is commonly reported in observational studies. However, higher quality scientific data have failed to demonstrate much evidence that such injections provide significant relief of pain or disability long term.
Epidural Steroid Injections
No randomized evaluations of cervical epidural steroid injections, translaminar or transforaminal, in managing axial neck pain have been reported. In one comparative trial, epidural injection of methylprednisolone and lidocaine demonstrated superior pain relief and function compared with intramuscular injection of the same agents at 4-week and 1-year follow-up in patients with chronic neck pain with radiation into the arm.
Facet Joint Injections
The facet or zygapophysial joints are paired diarthrodial articulations, with each joint receiving a dual nerve supply consisting of medial branch nerves derived from the dorsal primary rami of the two adjacent nerve root levels above and below each joint. They have been shown to be a source of pain in the neck, and referred pain in the head and upper extremities. Focal injections into the joint ( Figs. 5–1 and 5–2 ), or nerves that supply a particular joint, have been scrupulously studied as a diagnostic test. Single injections are subject to a high number of false-positive results. The joint or nerve block should consist of local anesthetic with near or complete relief of pain, and compared with injection of a placebo with minimal or no relief of pain on a separate occasion, to make diagnostic injection testing specific. Based on placebo-controlled diagnostic blocks, facet joints have been implicated as responsible for spinal pain in 54% to 67% of patients with neck pain. Placebo-controlled blocks, however, may be impractical and, indeed, unethical in a clinical setting. An alternative test determined to have good validity is the comparative block technique, which utilizes local anesthetics of known different duration placed in the same joints/medial branch nerves at separate settings. A recent systematic review of comparative local anesthetic injections or medial branch blocks has determined strong evidence in sensitivity, specificity, false-positive rates, and predictive value in the utility of diagnosing facet arthropathy as a source of neck pain.
