THE MANAGEMENT OF SPINE DISORDERS IS A KEY competency of physical medicine and rehabilitation. Physiatrists commonly take a lead role in the initial evaluation and management of patients with spine disorders. This chapter aims to discuss common disorders of the neck and low back.

Neck and back pain are common ailments of the musculoskeletal system. Nonspecific low back pain is one of the most common reasons for physician visits, with a lifetime prevalence of 80%. Only the common cold/upper respiratory infection is more responsible for patient visits to primary care physicians.^1,2 The direct medical costs to manage low back pain is upwards of $20 billion annually.³ The lifetime prevalence of neck pain is between 50% and 67%.⁴

Anatomy

The cervical spine consists of seven vertebrae. The atlanto-occipital joint is a major joint for cervical flexion and extension and is innervated by the C1 ventral ramus. The atlantoaxial joint consists of the anterolateral C1–C2 joints and the pivot of the dens of C2 on C1. The lateral atlantoaxial joint is innervated by the C2 ventral ramus. The articulation between the dens and C1 is innervated by the sinuvertebral nerves of C1–C3. Cervical rotation is 70 to 90 degrees with 40 to 45 degrees occurring at the C1–C2 joint.⁵ The C2–C3 facet joint is innervated by the medial branch (third occipital nerve) and articular branch of the posterior ramus of C3.⁶ The cervical facet joints from C3–T1 have an anterior to posterior, cephalad to caudad orientation, allowing for cervical lateral bending, greatest at C3–C4 and C4–C5, and cervical flexion and extension motion greatest at C5–C6 and C6–C7⁵ (Fig. 35–1). The loss of motion due to facet joint disease is due to the more coronal orientation of the facet joints.^5,7 The cervical facet joints are innervated by the medial branch of the dorsal ramus of the spinal nerve above and below the joint. The posterior cervical muscles are innervated by the cervical dorsal rami, while the anterior and lateral neck muscles are innervated by the cervical ventral rami. The intervertebral discs have a complex innervation that includes the posterior vertebral plexus (made up of the sinuvertebral nerves), anterior cervical plexus (made up of branches of the cervical sympathetic trunk), and vertebral nerve (branches of the cervical gray rami communicans)^5,7 (Fig. 35–2).

There are eight cervical nerve roots, each exiting above the same numbered vertebra, except for C8, which exits above T1. As the nerve root exits its neuroforamen, it is bordered by the uncovertebral joint anteriorly, facet joint posteriorly, and adjacent pedicles above and below.⁸

The cervical facet joint controls cervical spine motion, contributes to its stability, and provides proprioception regarding its position in space. The cervical facet joint surface area is about two-thirds that of the vertebral end plate. The facet joint surface is reciprocally convex and concave. Articular cartilage covers this surface. The cartilage rests on a thickened layer of subchondral bone and is surrounded at its margin by synovium. A superior and inferior capsular pouch, filled with fat, is formed at the poles of the joint, and a baggy fibrous joint capsule covers the joint like a hood. A fibroadipose meniscoid projects into the superior and inferior aspect of the joint and consists of a fold of synovium that encloses fat, collagen, and blood vessels. These meniscoids serve to increase the contact surface area when the facets are brought into contact with one another during motion, and slide during flexion of the joint to cover articular surfaces exposed by this movement.^6,7 The cervical facet joint is innervated by A-delta and c fibers in the dorsolateral aspect of the facet joint capsule, near the attachment of tendons and muscles. Mechanoreceptors are located in the facet joint capsule, highlighting a role in proprioception and in maintaining segment stability. It is postulated that damage to the facet joint capsule could lead to the development of joint osteoarthritis due to impaired joint mechanics. On average, 22.4% of the cervical facet joint capsule is covered with muscle, with direct muscle insertion into the facet joint capsule.⁶

Natural History and Biomechanics of Neck Pain

Osteoarthritis of the facet joints is most common in the C3–C5 segments. Radiological findings include degenerative and proliferative findings of joint space narrowing, subarticular bone erosion, subchondral cysts, osteophytes, and articular process hypertrophy. Magnetic resonance imaging (MRI) with fat-suppressed sequences is used to help with diagnosis. There is a relationship between the presence of osteoarthritis of the cervical spine and age and body mass index, but not to activity.⁷

In cervical spondylotic myelopathy with mild functional loss and MRI cord signal changes consistent with edema or injury, 56% of patients did not require surgery 5 or 10 years after presentation. Segmental kyphosis, segmental slip, and segmental motion on flexion/extension views were associated with an increased risk of requiring surgical treatment.⁹

Tumor and infection represent less than 0.4% of all episodes of neck pain. A similar incidence is seen with cervical fractures. Synovial cysts are most likely to present with radicular pain but are a rare incidence of spondylosis-related neck pain.⁷

Inflammatory arthropathies rarely result in neck pain alone, typically presenting with joint manifestations or other manifestations of systemic disease.¹⁰ The most common inflammatory arthropathy affecting the cervical spine is rheumatoid arthritis, affecting up to 86% of patients. The likelihood of cervical spine involvement and its severity are related to higher laboratory values (rheumatoid factor and C-reactive protein), the presence of erosions and nodules, and the age of disease onset. Pain is the most common manifestation, present in up to 80% of patients. Neck pain may radiate to the occipital, retro-orbital, or temporal area with or without muscle spasm. Neurologic symptoms can include radicular pain, radicular sensory loss, and weakness or myelopathy. The occipito-atlanto-axial junction is the most commonly affected due to the synovial characteristics of this articulation, although any cervical level can be affected. The inflammatory process of the joints leads to joint destruction (sometimes with pannus formation), ligamentous laxity, and segmental instability. Anterior subluxation of the axis is the most common and is due to laxity of the transverse ligament, although posterior subluxation is seen. Subluxation of more than 3 mm between C1 and the odontoid in flexion-extension films is considered abnormal. Furthermore, subluxation of more than 9 mm or a posterior atlantodental distance of less than 14 mm is associated with increased risk for cord compression. Destruction of the lateral atlantoaxial joints around the foramen magnum can lead to basilar invagination, risking brainstem or cord compression and sudden death due to odontoid invagination. Destruction of facet joints can result in subaxial subluxation, which, if it occurs at multiple levels, can result in the characteristic staircase appearance of the cervical spine on imaging. However, overall in rheumatoid arthritis, MRI is of greater value than computerized tomography (CT) to allow visualization of inflammation of the joints and ligaments as well as the degree of spinal cord stenosis.^11,12

Ankylosing spondylitis is noted by the squaring of vertebral bodies due to anterior and posterior spondylitis. Contrast-enhanced MRI helps in visualizing the locations of inflammation.¹³ Syndesmophytes and ankylosis ensue. The clinical manifestations of progressive loss of lordosis and involvement of costovertebral joints are common.⁷ Treatments include nonsteroidal anti-inflammatory drugs and tumor necrosis factor–blocking agents, with the latter being very effective in early disease.¹³ Pain severity does not correlate with the time course of the disease or radiographic findings.¹⁴

Psoriatic arthritis also affects the spine radiographically in up to 70% of cases, more commonly affecting the cervical spine. Ligamentous ossification and syndesmophyte formation is often present; alternatively, erosive features may predominate with subluxation. Gout can occasionally involve the axial skeleton, but data are sparse on the prevalence of spinal involvement. Tophaceous deposits in the facet joints might be identified on CT images.⁷ Inflammatory myopathy, specifically polymyositis and dermatomyositis, affect proximal muscles. The pharyngeal and neck extensor muscles are commonly involved, with dysphagia, neck pain, and neck weakness as common complaints.¹⁵

Diffuse idiopathic skeletal hyperostosis is a noninflammatory spine condition. Although usually presenting with trunk pain, patients can present with neck, low back, or radiating extremity pain. Up to 80% of patients will have morning stiffness.^16,17 Other symptoms of cervical spine involvement include hoarseness, stridor, aspiration, sleep apnea, and dysphagia.⁵ Radiological findings include ossification of the paravertebral ligaments and peripheral enthuses. Ossification of the anterolateral vertebrae is common, and cervical posterior longitudinal ligament ossification can be seen^5,16,17 (Fig. 35–3).

Polymyalgia rheumatic commonly presents in people over the age of 50 with otherwise unexplained morning stiffness of at least 30 minutes and pain in the neck and shoulder, although hip pain is not unusual. Systemic manifestations, including low-grade fever, fatigue, and weight loss, are common. The hallmark finding is a very high Westergren’s sedimentation rate. Patients respond to low-dose oral corticosteroid therapy. In up to one-third of patients, there is concomitant presence of giant cell arteritis, presenting with headache, jaw claudication, and visual disturbances.¹⁸

Fibromyalgia is a diffuse pain syndrome of unknown cause. It is estimated to affect 1% to 4% of the adult population in a 3:1 female to male ratio. It is not uncommon to present initially with neck and shoulder pain but invariably results in widespread pain. It commonly presents with other manifestations, including subjective fatigue, paresthesias, weakness, cognitive dysfunction, sleep disorder, and bowel dysfunction. Associated conditions include migraine headaches, irritable bowel syndrome, interstitial cystitis, chronic fatigue, vulvodynia, temporomandibular joint pain, chemical sensitivities, and noncardiac chest pain. Diagnosis requires the presence of pain on palpation of 11 of the 18 established tender points when pressure is applied at 4 kg/cm², and diffuse tenderness is common. Typical workup includes creatine phosphokinase, blood count, sedimentation rate, C-reactive protein, thyroid function tests, rheumatological screen, and imaging studies, which are normal. However, fibromyalgia is not uncommon in patients with other rheumatic conditions such as rheumatoid arthritis, systemic lupus erythematosus, Sjogren’s syndrome, ankylosing spondylitis, and polymyalgia rheumatica. The treatment of fibromyalgia involves education, aerobic exercise, cognitive behavioral therapy, stress management, sleep improvement, and pharmacological therapy. Medication management includes the use of tricyclic antidepressants, serotonin reuptake inhibitors, norepinephrine-serotonin reuptake inhibitors, gabapentin, and pregabalin.¹⁹

Types of Neck Pain

Radicular

The nerve root is compressed by a protruded or herniated disc anteriorly, by uncovertebral joint pathology causing encroachment anteriorly, by facet joint hypertrophy causing narrowing posteriorly, or by narrowing of the foramen vertically due to disc space narrowing. Foraminal narrowing is a more common cause of cervical radiculopathy than disc herniation by a ratio of 3:1. The C7 nerve root is the most commonly affected followed by C6, C8, and C5 in descending order of incidence⁸ (Fig. 35–4).

Facet-referred pain and intervertebral disc–related referred pain is a common presentation. From the C2–C3 level it is referred rostrally to the head, from C3–C4 and C4–C5 it is located over the posterior neck, from C5–C6 it spreads over the supraspinous fossa of the scapula, and from C6–C7 it spreads further caudally over the scapula.⁵ The key to differentiating is the constellation of other physical exam signs and symptoms related to the presence of referred pain.

Cervical spondylosis myelopathy can present with neck pain. The key finding is the relationship between neck pain, upper extremity radicular signs and symptoms, and upper motor neuron signs and symptoms in the distal upper extremities or lower extremities.^8,10

Mechanical

Facet joint pain is typically unilateral, nonradiating, and exacerbated by extension and rotation. Referred symptoms are common. Observation at rest and with motion and palpation are part of the physical examination, although correlation of findings with facet-mediated pain is lacking. There is low specificity of cervical radiographs, computerized tomography, and magnetic resonance imaging in correlating pain with facet arthrosis changes.⁶

A purported common mechanism for facet-mediated pain is cervical whiplash. With a rear impact, cervical spine motion is initially in flexion from the occiput to C2 and in extension below C2 with overall cervical compression,²⁰ resulting in lower cervical facet shear and distraction anteriorly and shear and compression posteriorly, while the upper cervical facet joints experience distraction and shear. Within 100 milliseconds, the primary motion is extension throughout the cervical spine. Subsequent to that, there is rebound flexion of the entire cervical spine with reversal of the lower cervical facet strain pattern. The flexion movement can result in annulus fibrosis strain /tear.²¹ At slow speeds, injury is most common at the C4–C5 disc but becomes more common at C3–C4, C5–C6, and C6–C7 as injury speed increases.⁵ Facet joint strain can increase by as much as a factor of 2, with the head in a flexed or rotated position at the time of impact.⁷

Cadaver studies show intra-articular hemorrhage as well as cartilage, subchondral bone, and articular process fractures. They also show lesions of the dorsal root ganglia, discs, ligaments, muscles, and vertebral artery after whiplash. The lack of valid diagnostic tests makes it impossible to evaluate the clinical relevance of these cadaver studies. Studies have indicated the role of psychosocial factors, stress, and pain centralization, but how these relate to the anatomic changes is uncertain.⁵

Studies using double-blind controlled medial branch blocks found that the prevalence of pain stemming from one or more zygapophysial joints was 60% among patients with chronic neck pain after whiplash. The most common locations are C5–C6 and C6–C7. However, in patients with neck pain and headache after whiplash, 27% had pain from C2–C3.²²

Up to 50% of patients who present with cervical whiplash will have continued complaints a year after injury. Predictors of chronicity include higher initial pain intensity, higher level of pain-related disability, and lower expectation of recovery. Increased sensitivity to cold stimulation is related to whiplash outcome. There is some evidence regarding the relationship between whiplash outcome and post-traumatic stress, lower self-efficacy, pain catastrophizing, depression, and fear avoidance. Mechanical hyperalgesia and range of motion have had conflicting reports of relationship to whiplash outcome.²³

Noncervical Neck Pain

One must consider noncervical spine causes for neck pain. Less common neuromusculoskeletal conditions include Eagle’s syndrome (elongated styloid process, presenting with painful swallowing and ear pain), carotidynia (to be distinguished from carotid artery dissection, Takayasu’s arteritis, and septic embolization), glossopharyngeal neuralgia (idiopathic, traumatic, and cerebellopontine angle (CPA) vascular or tumor compression are common causes), superior laryngeal neuralgia, hyoid bone syndrome, acute calcific retropharyngeal tendinitis (acute neck pain and stiffness with restricted range of motion [ROM] and pain with swallowing, inflammation, and edema of the upper portions of the longus colli from C1–C4)⁵, temporal tendinitis, thyroid and cricoid cartilage syndromes, and mastoid process syndrome.²⁴

Atypical presentation of myocardial infarction with neck pain is not uncommon, especially in women.^5,25 Neck pain that is unilateral and anterolateral is seen in 25% to 50% of persons with cervical carotid artery dissection, only 10% with this as the only presenting symptom. Neck pain can precede Horner’s syndrome, cranial nerve palsies, and stroke symptoms by an average of 3 to 4 days. This is important, as carotid dissection represents the cause of stroke in up to 20% of persons under the age of 45.²⁶ Vertebral artery dissection can also present with neck or head pain, although stroke symptoms were seen in more than 60% of patients.²⁷ Although aortic aneurysm dissections typically present with chest pain and cardiovascular symptoms, neck pain has been reported as a presenting symptom in up to 6% of cases.⁵ Dental pain, pneumonia, and peptic ulcer disease can cause referred symptoms of neck pain.¹⁰

Diagnosis

History and Physical Exam

The history of neck pain should focus on the onset and time course, pain location, pain severity, presence or absence of radiation, alleviating and aggravating factors, and associated symptoms. Inquiry should include the presence of red flag issues, including fever, unexplained weight loss, history of cancer, history of trauma, history of steroid use, history of osteoporosis, failure to improve with treatment, history of substance abuse, HIV status, presence of lower-extremity spasticity, or change in bowel or bladder control. Important psychosocial variables that are related to neck pain include poor self-assessed health, poor socioeconomic status, history of chronic low back pain, history of prior neck injury, dissatisfaction with work, perceived increased work stress, and worker’s compensation payments.

The key components of the physical examination include general appearance, inspection, palpation, range of motion, tendon reflexes, motor strength testing, sensory testing to light touch and pinprick, Spurling’s maneuver, and shoulder examination.²⁸

Observation should include checking overall spinal alignment or posture from an anterior, posterior, and lateral view. This allows the examiner to identify areas of scoliosis, deformity, postural misalignment, and spasm that may contribute to the patient’s complaint. During this phase, one should also look for skin rashes, scars from prior surgeries, and muscle bulk asymmetries or spasm. Observation of the degree of cervical lordosis or torticollis should be made (Fig. 35–5).

Palpation of both bony and soft tissue sites of common pain is important to identify common axial and peripheral referral structures. They should be palpated when the muscles are relaxed, making a supine examination reasonable. Bony landmarks that should be palpated are spinous processes, cervical facet joints, occiput, upper thoracic ribs, acromioclavicular (AC) and sternoclavicular (SC) joints, and mastoid process. Soft tissue areas that should be palpated include the trapezius, cervical paraspinal muscles, splenius, levator scapulae, rhomboid, and rotator cuff. Trigger points and tissue tenderness as well as rigidity should be noted. Referred pain from palpation of these areas should be noted.

Motor strength testing should be focused on key myotomal muscle groups to include shoulder abduction (axillary and suprascapular nerves, C5–C6), shoulder external rotation (suprascapular nerve, C5), elbow flexors (musculocutaneous and radial nerves, C5–C6), elbow extensors (radial nerve, C6–C7), wrist extensors (radial nerve, C6–C7), wrist flexors (median nerve, C7–C8), finger flexors (median nerve, C8), thumb abduction (median nerve, C8–T1), and first dorsal interosseous (ulnar nerve, C8–T1).

Sensory testing should be undertaken in a careful manner to elucidate the type and location of sensory abnormalities. Sensation should be recorded as normal, anesthetic, or hyperesthetic for each modality tested, such as light touch, pain, temperature, and vibration. The sensory examination should be subdivided into a standard dermatomal exam that systematically evaluates each dermatome with light touch and cold to cover the upper limbs (see Fig. 35–6). After completing the dermatome exam, another systematic approach to cover the peripheral nerve distributions should be completed (see Fig. 35–6).

Provocative maneuvers include Spurling’s compression test, which consists of passive cervical lateral bending, extension, and compression. A positive test reproduces ipsilateral radicular symptoms. Sensitivity and specificity have been reported as 40% to 60% and 92% to 100%, respectively. Spurling’s test has been shown to have a specificity of 93% and sensitivity of 30% in detecting cervical radiculopathy, indicating its use as a confirmative examination and not necessarily for screening.²⁹ Adson’s test consists of inspiration, chin elevation, and head rotation to the affected side. A positive test alters or obliterates the radial pulse. Sensitivity is reported at 94%, but specificity ranges from 18% to 87%.

In evaluating radicular cervical pain and the likelihood of having a positive electromyography, symptoms have low sensitivities and low specificities with a nonsignificant odds ratio. In spite of the poor sensitivity of physical exam findings in predicting a normal electromyography (EMG), the presence of physical examination findings of weakness, reflex change, or sensory loss of the arm confer a four to five times higher probability of having a positive EMG study and a two to nine times higher probability that the study will confirm a cervical radiculopathy. A positive biceps reflex increases the odds ratio of a positive electromyography by a factor of 10. However, no symptom significantly predicts a positive electromyography test result for radiculopathy.³⁰ In addition, up to 48% of patients with electromyography-confirmed radiculopathy have a normal physical examination. In addition, brachial plexus anomalous innervation patterns can confound the relationship between the physical examination and imaging findings. The most common variants of brachial plexus organization are described as “prefixed” (up to 48%) and “postfixed” (0.5% to 4%).³⁰

Common causes of neck pain include cervical sprain/strain, cervical facet pain, and cervical discogenic pain, although less common causes such as atlantoaxial instability should be considered. Common mimics of neck pain include shoulder pain, connective tissue disorders, and non-neuromuscular skeletal disorders. Common causes of radiculopathy include herniated disc, radiculitis, spondylosis, and stenosis, although tumor-related, ischemic, and inflammatory causes should be kept in mind. Common mimics of radiculopathy include entrapment neuropathy, brachial plexopathy (brachial neuritis and thoracic outlet syndrome, Pancoast tumor), polyneuropathy, complex regional pain syndrome (Yoon), myelopathy, and central etiologies. Musculoskeletal disorders that mimic radiculopathy include myofascial pain syndrome, connective tissue disorder, subacromial and subdeltoid bursitis, lateral epicondylitis of the elbow, and de Quervain’s tenosynovitis.¹⁰

There is common overlap between musculoskeletal and neurologic causes of neck pain. Musculoskeletal diagnoses were discovered in 69% of patients with a normal EMG but in 29% of those with confirmed radiculopathy and 45% in patients with other confirmed neurologic abnormality.³¹

Imaging

The use of plain radiographs for cervical spine pain is recommended for red flag issues that include age of onset less than 20 years, age of onset greater than 55 years, constitutional symptoms, history of cancer, history of immunosuppression, and history of intravenous drug abuse.³² Patients with prior cervical fusion, rheumatoid arthritis, and Down’s syndrome should have anteroposterior (AP), lateral, and open-mouth views obtained to demonstrate no odontoid fracture or subluxation before proceeding to dynamic radiographs. Basilar invagination can be seen on lateral or open-mouth odontoid views, with 5 mm being associated with increased neurologic risk.³²

Klippel–Feil anomaly of congenitally fused cervical vertebral bodies is seen on plain radiographs. They are typed as follows: I with a single fused segment, II with multiple noncontiguous fused segments, and III with multiple contiguous fused segments.³²

Atlanto-occipital subluxation is seen in rheumatoid arthritis, Down’s syndrome, Klippel–Feil syndrome, os odontoideum, Morquio’s syndrome, and connective tissue diseases. Atlantoaxial instability in rheumatoid arthritis is due to synovial inflammation leading to bone and cartilage injury and ligamentous instability, most commonly at the alar and transverse ligament. An anterior atlanto-odontoid interval of more than 3 mm is consistent with subluxation, while more than 9 mm requires surgical referral. A posterior atlanto-odontoid interval of less than 14 mm correlates with a higher likelihood of cord compression.³²

In trauma, the NEXUS study identifies that not all patients need cervical radiographs. Patients with no midline cervical tenderness, no intoxication, normal level of consciousness, no focal neurologic deficit, and no distracting injury mechanism are considered low probability and do not require imaging.³³ A three-step Canadian algorithm has been developed. Any patient with high-risk factors, age greater than 65, dangerous mechanism of injury, or presence of paresthesias should get plain radiographs. Any patient in a rear-end motor vehicle crash who is able to ambulate and sit with delayed-onset pain and no midline tenderness does not need radiographs. Any patient unable to rotate the neck 45 degrees in both directions requires radiographs.³⁴

Ultrasound has been used as an injection guidance tool for cervical facet blocks and cervical medial branch blocks and radiofrequency ablation. Cadaver studies in medial branch guidance showed successful localization in 30 of 34. Ultrasound approaches exist for greater occipital nerve block.

Depending on imaging alone to identify the cause of neck pain is a trap fraught with error. One study of 94 asymptomatic persons with mean age of 48 +/− 13 years demonstrated that 90% had positive MRI scans of the cervical spine, including more than 75% with posterior protrusions and 80% with anterior compression of the spinal canal. Age was related to decrease in disc signal intensity and posterior protrusion, while smoking history was related to posterior protrusion and anterior compression of the spinal canal.^10,35

EMG

The purpose of electromyography is to evaluate for radicular cervical pain and for its mimics, especially brachial plexopathy and entrapment neuropathies.³⁶ In a study of 101 patients with confirmed cervical radiculopathy, electromyographic examination of the paraspinal muscles demonstrated that six muscles with paraspinal findings identified 94% to 99% of cases, while seven muscles with paraspinal findings identified 96% to 100%. Without paraspinal examination, a comparable identification of 92% to 95% required an eight-muscle screen.³⁷ Using abnormal spontaneous activity as criteria for abnormality, the infraspinatus, supraspinatus, biceps, deltoid, and brachioradialis showed equal incidences of being affected in a C5 radiculopathy. Similarly, the flexor carpi radialis, anconeus, pronator teres, and triceps were affected in C7 radiculopathy, and the first dorsal interosseous of the hand, extensor indicis, and abductor digiti minimi were affected in C8 radiculopathy with less frequent involvement of the flexor pollicis longus and abductor pollicis brevis.

The most variable presentation was with C6 radiculopathy, which can mimic C7 or can mimic C5 with the added involvement of the pronator teres.³⁸

Routine median and ulnar F-response latencies are of limited value in cervical radiculopathy evaluation due to the relatively lower incidence of C8/T1 radiculopathy.³⁶ The use of the flexor carpi radialis H-reflex has not gained widespread use. It is found in 90% of normal patients, with sensitivities and specificities of 50% and 86% in C6 radiculopathy and 75% and 86% in C7 radiculopathy, respectively.^39,40

Diagnostic Injections/Invasive Tests

Cervical medial branch blocks have a false-positive rate of 37% to 50% compared to performance of two sequential differential blocks.⁴¹

There is limited support for provocative discography for evaluation of axial neck pain in considering surgery, although this has not achieved consensus. Studies supporting this are older than 15 years old with no reproduced findings.⁴²

Treatment

Procedures

Epidural injection for cervical radicular pain is effective for short-term and intermediate-term pain management. The mechanisms of action are related to the epidural. Studies indicate that epidural injection improves spine pain better than nonepidural injection and that for epidural injection, the difference between epidural injection and no injection is greater than the difference between epidural injection and steroid epidural injection. Based on these findings, the mechanism of action proposed includes unwinding central sensitization, enhancing blood flow to ischemic nerve roots, diluting inflammatory cytokines, lysing scar tissue, and suppressing ectopic nerve firing.⁴³

Trigger point injections have demonstrated efficacy in the management of myofascial pain of the cervical spine. Dry needling has demonstrated improvement over 0 to 3 days, wet needling over 0 to 28 days. No study has demonstrated benefit that lasts beyond 2 to 6 months.⁴⁴ Similarly, no study has demonstrated efficacy of trigger point injections in the management of tender points.

Therapy (Including Multidisciplinary Team)

In the management of chronic neck pain, multimodal exercise therapy is noted to be most beneficial. However, there was significant benefit from strength training in pain level, strength, function, and quality-of-life measures in patients with chronic neck pain.⁴⁵ In addition, therapeutic exercise results in up to 6 months’ improvement in pain measures but not in function in patients with chronic nonspecific neck pain.⁴⁶ In patients with chronic neck pain, cervical manipulation has been demonstrated to be better than a control group, but more improvement in pain measures is seen with exercise than with manipulation alone.⁴⁷ Similarly, cervical manipulation is better than medications or passive modalities in acute neck pain, but cervical manipulation was not more effective than home exercise therapy with advice.⁴⁷ There is evidence that in the acute management of neck pain, physical therapy is more effective than natural history. In patients with acute neck pain there is low-level evidence that a collar is no more effective compared with physical therapy on pain and very low-level evidence that a collar is more effective compared with physical therapy on function in the first 6 weeks after presentation.⁴⁸

Cervical traction does not have demonstrated efficacy in treating patients with chronic neck pain with or without radiculopathy. For patients with cervical radiculopathy, there is low-level evidence that traction is no more effective than placebo traction.⁴⁹ Immobilization with a collar is no more effective than physical therapy, and there is very low-level evidence that a collar is no more effective than traction, but that a collar was significantly better than no treatment on upper extremity radicular pain at 6 weeks after acute cervical radiculopathy but not at 6 months.

Low-level laser therapy in eight randomized controlled studies of patients with neck pain resulted in statistically significant improvement in pain that was not clinically significant (Visual Analog Scale [VAS] improvement of 10.54/100, confidence interval 0.37 to 20.71).⁵⁰ The evidence for electrotherapy in the treatment of neck pain remains of low quality. Pulsed electromagnetic field therapy, repetitive magnetic stimulation, and transcutaneous electrical nerve stimulation may be more effective, but this has not been clearly demonstrated. Current studies on galvanic current therapy, iontophoresis, neuromuscular electrical stimulation, and static magnetic field therapy did not reduce pain or disability.⁵¹

Surgery

Surgical treatment for cervical disc herniation is considered for patients who fail conservative management, have intractable pain, or have progressive neurologic deficits. The type of cervical intervention depends in part on the anatomic location of the cervical disc herniation. A posterior cervical foraminotomy is considered for the patient with unilateral radicular symptoms, no instability on flexion-extension radiographs, and a far lateral disc herniation on magnetic resonance imaging. However, it is not indicated for patients with compression from uncovertebral joint hypertrophy. Patients with central or paracentral herniations on MRI with either unilateral or bilateral radicular findings can be treated with an anterior cervical discectomy and fusion. Through an anterior approach, both neuroforamina can be decompressed.⁴² Systematic reviews have shown no short-term differences in anterior discectomy with or without fusion, although some longer-term benefit is seen in the fusion group with regard to pain and function.⁵²

A meta-analysis of 1,745 patients comparing cervical disc arthroplasty versus fusion for single-level symptomatic cervical disc disease favored cervical disc arthroplasty for overall and neurologic success, incidence of dysphagia, and adjacent segment degeneration. No difference was noted in neck disability index, neck pain, arm pain, or surgical complications or reoperation rates. However, long-term results are not available regarding the purported benefit of preventing adjacent segment degeneration.⁵³ A Cochrane review of 2,400 patients in nine studies showed small differences in favor of arthroplasty for neck-related function and neurologic outcome over the first 2 years after surgery. There was a large difference in segment mobility in favor of arthroplasty. There was low-quality evidence of no difference in adjacent segment surgery rates over 2 years after initial surgery and no difference in all other outcome measures, including pain and patient satisfaction.⁵⁴

Adjacent segment degeneration has a cumulative annual incidence of 0.8%. The incidence of secondary cervical fusion surgery for adjacent segment disease is 7.6 per 1,000 person-years. A 10-year cohort of 20,000 patients showed that 5.6% of patients required a second operation, most commonly in younger and male patients with an average time of 23.3 months between surgeries.⁵⁵

Surgical intervention for cervical myelopathy involves decompression of the spinal cord through either an anterior or a posterior approach. Both necessitate a fusion and have yielded excellent results.⁴²

Another technique is a laminoplasty, which preserves cervical motion by hinging open the laminae, thereby increasing the space available for the cord without a fusion. If patients have minimal neck pain, laminoplasty is an option and has yielded similar outcomes to decompression and fusion in patients without preoperative instability.⁵⁶

Anatomy

The lumbar spine consists of five vertebrae. Lumbar rotation is 18 degrees with 20 degrees of lateral bending and 60 degrees of lumbar flexion, with 35 degrees of lumbar extension. The lumbar facet joints have a lateral to medial and posterior to anterior orientation, allowing for lumbar flexion bending, greatest at L4–L5. The lumbar facet joints are innervated by the medial branch of the dorsal ramus of the spinal nerve above and below the joint. The posterior lumbar muscles are innervated by the lumbar dorsal rami with unisegmental innervation of the multifidus muscle. The intervertebral discs are innervated by the rami communicans.

There are five lumbar and five sacral roots. The lumbar roots exit below the same numbered vertebra, and the sacral roots exit through the anterior sacral foramina. As the lumbar nerve root exits its neuroforamen, it is bordered by the pedicles above and below; the intervertebral disc and vertebral bodies anteriorly; and the ligamentum flavum, pars interarticularis, and facet joint posteriorly. The L1 and L2 lumbar nerve roots exit in a fairly perpendicular orientation, while the angle of exit for the lower lumbar nerve roots is more acute.⁵⁷

The lumbar facet joint controls lumbar spine motion, contributes to its stability, and provides proprioception regarding its position in space. The anterior lumbar facet joint capsule interdigitates with the ligamentum flavum, while the posterior capsule receives a tendinous attachment from the multifidus. Although the orientation of the posterior midfacet capsule fibers is horizontal, the superior and inferior fibers have a more slanted orientation, allowing for more lumbar flexion range of motion⁵⁸ (Fig. 35–7).

Disc herniations are classified based on the extent of the herniation in relation to the vertebral body. Protrusions herniate past the boundary of the vertebral body and do not have a neck, extrusions herniate past the boundary of the vertebral body and have a neck, and a sequestered fragment is a free-floating fragment that has herniated past the boundary of the vertebral body (Fig. 35–8).

Natural History

The vast majority of individuals with an acute episode of back pain will recover in 1 to 3 months.⁶ For a small group of individuals the pain becomes a chronic, unremitting problem that can severely limit activities of daily living and participation in their occupation. Natural history of all undifferentiated back pain generally follows a path of quick resolution, regardless of treatment in the acute stage.⁵⁹ Natural history of specific disorders is difficult to quantify, as most studies of lumbar disc herniation, spinal stenosis, and radiculopathy have selection bias, in that diagnostic studies are not always undertaken at initial symptom onset; those individuals whose symptoms resolve quickly may not seek care, and most studies involve some level of conservative treatment at a minimum.