Diagnosis and Management of Cervical Spondylosis Treatment & Management

A brief discussion of the natural history of symptomatic cervical spondylosis is necessary before discussing therapeutic intervention.

Cervical radiculopathy usually resolves without intervention. The long-term prognosis in cervical spondylotic myelopathy is less clear. Some patients experience a progressive decline, while most have long periods of stability of symptoms with intermittent exacerbations.

One study noted that 79% of patients with neck pain and/or referred pain syndromes and cervical spondylosis improved or became asymptomatic by the 15-year follow-up point. ^[32] Medical treatments for cervical spondylosis include neck immobilization, pharmacologic treatments, lifestyle modifications, and physical modalities (eg, traction, manipulation, exercises). No carefully controlled trials have compared these modalities; therefore, these therapies are often initiated based on a clinician's preference or specialty. Comparing the efficacy of these treatments against no treatment is difficult.

Neck immobilization (with a soft collar, Philadelphia collar, rigid orthoses, Minerva jacket, or a molded cervical pillow for support) is a common, nonoperative treatment for neck pain and/or suboccipital pain syndromes caused by spondylosis and cervical radiculopathy.

• Despite widespread use, soft collars are largely believed to work by placebo effect because they do not appreciably limit motion of the cervical spine. They have not been demonstrated to change long-term outcomes. If worn properly, a soft collar maintains relative flexion. The collar should be worn as long as possible during the day. However, patient comfort is key.

• As symptoms improve, the collar can be worn only during strenuous activity. Eventually, it can be discontinued. More rigid collars and devices may better limit motion of the cervical spine, but they may reduce muscle tone and cause neck stiffness from disuse. Implement a daily cervical exercise program to limit loss of muscle tone.

Pharmacologic treatment includes several options.

• NSAIDs are the mainstay of pharmacologic treatment. They are effective in reducing the biologic effects of inflammation and pain. Their use should be monitored for adverse effects such as gastropathy, renal toxicity, hypertension, liver abnormalities, and bleeding. Selective inhibitors of cyclooxygenase-2 (COX-2) such as celecoxib can lower the risk of gastrointestinal toxicity, but recent studies have raised concerns of the association of this class of drugs with higher cardiovascular events, particularly at higher doses.

• Patients who experience more chronic pain symptoms may benefit from tricyclic antidepressants (TCAs). Common side effects include dry mouth, sedation, urinary retention, constipation, and cardiac conduction blocks.

• Muscle relaxants such as carisoprodol and cyclobenzaprine may also be beneficial in patients with a spasm in the neck muscles (which can be related to spondylotic changes).

• Opioids could be considered in patients who have moderate-to-severe pain due to significant structural spondylosis, whose who are poor surgical candidates, and those who have failed nonopioid agents. For patients who are at risk for NSAID toxicity, particularly the geriatric population, opioids are reasonable alternatives. ^[33] However, opioids should be avoided if there is history of substance abuse or mood disorder.

• Steroid use is controversial. In some patients with severe radiculopathy, a high-dose oral steroid taper may rapidly reduce pain and shorten the course of symptoms. Some patients with progressive cervical spondylotic myelopathy also may benefit. Epidural steroid injections may help patients with radicular symptoms. Patients who present within 8 hours of an acute central cord injury (which can be caused partly by ventral osteophytes) may benefit from high doses of methylprednisolone.

• No placebo controlled trials have studied gabapentin in cervical spondylosis, but based on its efficacy in controlling neuropathic pain, it is often being used off label for chronic pain associated with cervical spondylosis.

Lifestyle modifications (eg, neck schools, instruction in body mechanics, relaxation techniques, postural awareness, ergonomics and/or workplace modifications) may alleviate symptoms.

• Neck school is a form of small group therapy that provides techniques to patients who are willing to actively work toward recovery. It may be of limited clinical value.

• Instruction in body mechanics focuses on low-load concepts. These include avoiding forward bending and rotation of the neck, avoiding prolonged extension of the neck, avoiding prolonged sitting or standing, and selecting the proper chair.

• Workplace modifications and ergonomics serve to reduce strenuous neck positions during work and leisure.

Physical modalities are among the oldest treatments used for spine-related disorders.

Cervical mechanical traction, commonly used for cervical radiculopathy, in addition to cervical joint distraction, may loosen adhesions within the dural sleeves, reduce compression and irritation of discs, and improve circulation within the epidural space.

• Studies regarding its efficacy are conflicting, with intermittent traction probably being more effective than static traction. Initially, a weight of 10 lb is recommended, eventually increasing to 20 lb as tolerated.

• It can be used at home 2-3 times daily for 15 minutes at a time. It is contraindicated in patients who have myelopathy, a positive Lhermitte sign, or rheumatoid arthritis with atlantoaxial subluxation. A retrospective study found that cervical traction provided symptomatic relief in 81% of the patients with mild-to-moderately severe cervical spondylosis syndromes. ^[34]

Manipulation, most commonly practiced by chiropractors and osteopathic physicians, was described as early as 4000 years ago. It remains a popular treatment for back pain.

• Techniques vary and include low-velocity, high-amplitude manipulation; high-velocity, low-amplitude manipulation (eg, thrusting or impulse manipulation); and nonthrusting maneuvers. Studies have reported conflicting results, and few well-controlled studies specifically concerning the treatment of cervical spondylosis symptoms have been published.

• Contraindications to cervical manipulation include vertebral fractures, dislocations, infections, malignancy, spondylolisthesis, myelopathy, various rheumatologic and connective-tissue disorders, and the presence of objective signs of nerve root compromise. The most feared complication of cervical manipulation, vertebrobasilar artery dissection, is rare and almost impossible to predict despite multiple proposed risk factors.

Exercises designed for cervical pain include isometric neck strengthening routines, neck and shoulder stretching and flexibility exercises, back strengthening exercises, and aerobic exercises. Controlled trials regarding the efficacy of these routines are lacking.

Other commonly used modalities for pain include heat, cold, acupuncture, massage, trigger-point injection, transcutaneous electrical nerve stimulation, and low-power cold laser. Most of the passive modalities used for degenerative disease of the cervical spine are performed by physical therapists and are most efficacious in combination.

Surgical care for cervical spondylosis involves anatomic correction of the degenerative pathologic entities that compress a nerve root or the spinal cord.

Indications for surgery include intractable pain, progressive neurologic deficits, and documented compression of nerve roots or of the spinal cord that leads to progressive symptoms. Surgery has not been proven to help neck pain and/or suboccipital pain. Several approaches to the cervical spine have been proposed. The approach selected is determined based on the type and location of pathology and the surgeon's preference.

Cervical radiculopathy traditionally has been approached either via the anterior approach, which was first described by Robinson and Smith in 1955, or the posterolateral approach, during which a "keyhole" foraminotomy is performed.

The anterior approach allows excellent access to midline disease and visualization of pathology without manipulation of neural elements. Robinson and Smith proposed that the anterior approach coupled with fusion using an iliac crest bone graft (autograft) arrests progressive spondylotic spurring, causes existing osteophytes to eventually regress as a result of spinal stability promoted by fusion, decompresses and enlarges the neural foramen and spinal canal by the distraction of the disk space, and minimizes surgical manipulation of the contents of the spinal canal, thereby minimizing complications.

More recently, use of allografts, which could be in form of bone graft obtained from cadavers, or ventral cervical plating have become more popular as they eliminate morbidity of harvesting the graft. ^[35] Success of fusion is higher with autografts due to the presence of endogenous morphogenetic proteins that are present in the harvested bones and help with osteoinduction. Research is being performed on the use of recombinant human morphogenetic proteins to improve success of fusion with allografts. ^[36]

When performed with fusion, anterior cervical diskectomy (ACD) yields good-to-excellent results in almost 90% of patients when no other level of spondylosis is present. When adjacent levels of spondylosis were demonstrated, only 60% of patients had good-to-excellent results.

ACD without fusion has been used based on the nonexistent correlation between successful fusion and clinical outcome and the significant incidence of pseudoarthrosis following ACD and fusion (10-20%). The advantage of this procedure is the lack of bone graft–related complications and decreased manipulation and dissection of the cervical tissues. Patients who do not undergo fusion often report a shorter postoperative hospital stay and an earlier return to daily activities.

ACD without fusion almost inevitably is followed by disk-space collapse. This procedure does not accomplish disk-space distraction and does not mechanically open the neural foramina. It does not promote stabilization of the motion segment to promote resorption of osteophytes. As a result, most surgeons choose ACD with fusion for patients with cervical radiculopathy when taking an anterior surgical approach. Instability of the cervical spine is rarely reported following ACD with or without fusion, but the incidence of postoperative neck pain is higher without fusion.

The posterolateral approach to cervical radiculopathy has similar results to the anterior approach when used for the proper indications. This approach is associated with greater initial postoperative discomfort but avoids the possibility of graft dislodgment and damage to neck structures. It is best used for nerve root decompression, when the pathologic entity is a lateral spondylotic spur or soft disk. In this approach, a keyhole foraminotomy is made by removing the medial third of the facet joint and the most lateral aspects of the lamina at the involved level and side. The underlying lateral aspect of the ligamentum flavum is then removed to visualize the nerve root. The nerve root is unroofed posteriorly, superiorly, and inferiorly so that it lies free and without tension.

The impact of facetectomies on the stability of the cervical spine has been questioned. Bilateral 50% facetectomies have been demonstrated to expose the nerve by 3-5 mm without a notable effect on stability. Bilateral facetectomies of 70% reduced the ability of the spine to withstand stresses, while increasing the exposure of the nerve root. In all likelihood, maintenance of the interspinous and most of the interlaminar ligaments is important for preserving stability in patients undergoing foraminotomy.

Surgical intervention for cervical spondylotic myelopathy is controversial.

In 1992, a thorough review of the literature pertaining to surgery for cervical spondylotic myelopathy concluded that the chances for improvement after surgery for cervical spondylotic myelopathy were approximately 50%. The conclusion was that large multicenter trials are needed to determine the benefit of surgery and to establish criteria for the operation/approach of operation. Also noted was that diagnostic errors still occur, namely with amyotrophic lateral sclerosis and multiple sclerosis. ^[37]

Risks of surgery are another concern. The older literature reviewed by Rowland has been criticized because of uncertainty as to whether nonspondylotic causes of myelopathy were excluded prior to surgery. With current early intervention strategies tailored to the pathophysiology of myelopathy, final outcomes clearly exceed expectant outcomes. Rowland noted in his proposed trial guidelines that patients with rapid progression of myelopathy may be allowed access to surgery without a trial of conservative therapy.

In the United States, cervical immobilization with a collar or brace is the most commonly used therapy for cervical spondylotic myelopathy. Studies demonstrate conflicting results regarding efficacy of this treatment.

Researchers have reported that symptomatic patients may deteriorate neurologically during bracing; thus, surgery is usually recommended in patients with moderate-to-severe disability or frank myelopathy. Because of the possible progressive character of cervical spondylotic myelopathy, some advocate a more aggressive approach to the disease to strive for improved outcomes.

The natural history of cervical spondylotic myelopathy is highly variable. The older literature notes the natural course of cervical spondylotic myelopathy to be that of progressive disability and deterioration in neurologic function. Nurick, however, noted that a period of initial deterioration occurs, followed by a clinical plateau that lasts for several years, during which disability does not worsen for those with mild cervical spondylotic myelopathy. He noted that older patients deteriorate more frequently and, thus, advocates surgery for those older than 60 years and for those with progressive decline in neurologic function. ^[38]

Another factor that must be taken into consideration is that patients with cervical spondylotic myelopathy may be at risk for significant spinal cord injury, even with minor trauma. This argument, in addition to improved surgical outcomes in those with decreased duration of symptoms, has been used as an argument supporting surgery.

Nevertheless, a Cochrane review found the natural course of cervical spondylotic myelopathy to be highly variable for patients with mild-to-moderate symptoms, in whom the review noted the disease to often remain static and symptoms to occasionally improve. ^[39] Similarly, for mild-to-moderate cervical spondylotic myelopathy, a 3-year prospective randomized trial found no significant difference between patients who were treated surgically and those who were treated conservatively. ^[40]

Excellent results have been demonstrated for patients undergoing surgical intervention. One prospective trial of 503 patients undergoing conservative management for cervical spondylotic myelopathy versus surgery reported that patients treated surgically had better outcomes than those treated medically and that medical treatment did not significantly alter neurologic outcomes. ^[41]

Accurately prognosticating the course of disability for any given individual with cervical spondylotic myelopathy is difficult. Once moderate signs and symptoms develop, however, surgical intervention is likely to be beneficial over further medical treatment.

The primary goal of surgery for cervical spondylotic myelopathy is decompression of the spinal cord. ^[42] Traditionally, for cervical laminectomy, a posterior approach has been the treatment of choice. During the previous 20 years, laminectomy has increasingly been recognized as not appropriate for all patients. Neurologic deterioration, which has been reported after laminectomy, has been attributed to the development of spinal instability and kyphotic deformities. Laminectomy also is unable to address ventral osteophytic overgrowth via a posterior approach. Through an anterior cervical approach, one can directly remove osteophytes, disk material, and even vertebral bodies, if necessary, to decompress the cord. With interposition of bone grafts and, in some instances, cervical plates (ie, instrumentation), neck instability can be prevented.

The sagittal alignment of the cervical spine is important in choosing an approach for decompressing the cervical cord in cervical spondylotic myelopathy.

Preoperative lordotic alignment of the cervical spine is necessary in order to maintain maximal benefit from posterior decompression. This is because of both the direct decompression of the cord achieved by surgical removal of compressive elements (eg, ligamentum flavum, bone) and the indirect decompression achieved ventrally by posterior drift of the spinal cord.

Fixed local or global kyphosis, therefore, may be a relative contraindication for posterior decompression. ^[43] In the case of kyphosis, general insufficiency of the anterior column is caused by degenerative changes in diskoligamentous structures, leading to neutralization or inversion of the physiologic cervical lordosis. Because of kyphosis, the cord shifts forward and is compressed by anterior osteophytes.

In cases of combined anterior compression and posterior bulging of the ligamentum flavum causing narrowing of the vertebral canal, a combined anteroposterior approach may be recommended.

The posterior approach (often advocated by Japanese surgeons) is also accepted as a standard decompression procedure in patients who have more than 3 segments of stenotic changes. The anterior approach involves an extensive resection.

Laminoplasty (a modern approach) and its variants preserve the lamina to avoid excessive scar formation and to reduce the incidence of postlaminectomy kyphosis. Excellent laminoplasty results have been reported for the treatment of multilevel cervical spondylotic myelopathy. ^[44] Additionally, long-term results with laminoplasty have been reported with fewer late complications then laminectomy. ^[45] Nevertheless, some authorities advocate laminectomy. ^{[2, 46]} Laminectomy combined with lateral mass fusion may yield excellent results without progression to spinal instability or kyphosis. ^{[47, 48, 49]}

The anterior approach is advocated for cervical spondylotic myelopathy when identifiable anterior compression or kyphotic deformity is present. This approach is more frequently used in the United States because ventral compression is more common. Myelopathy due to osteophytes confined to 1-2 levels is treated using ACD and fusion with removal of the osteophytes. In severe cases, extensive decompression is performed using multilevel vertebrectomies (corpectomy) and reconstruction with bone graft and instrumentation. Recent series have reported clinical improvement rates ranging from 80-94%. ^{[50, 51]} Neither the anterior nor posterior approach has been demonstrated superior to the other, provided the appropriate procedure is performed for the proper clinical indication. ^{[2, 52, 46]}

Minimally invasive surgical techniques are being developed for management of cervical spondylosis causing foraminal or central canal stenosis manifesting as radiculopathy, myelopathy or both. In these cases, dorsal laminoforaminotomy can be performed with minimally invasive techniques using microendoscope and tubular retractor system. Typically, these cases are performed with electromyographic and somatosensory evoked potential monitoring. The goal of these techniques is to minimize injury to surrounding tissue, which leads to better outcomes with less pain. ^[53]

Artificial cervical disks were approved by the US Food and Drug Administration (FDA) in 2007 and are now being offered as an alternative to spinal fusion in some selected patients. Replacement with an artificial disk can potentially preserve natural neck motion and thereby reduce stress and prevent degeneration of adjoining cervical disks. A study comparing artificial cervical disk replacement with cervical fusion concluded that patients who had undergone artificial cervical disk replacement had faster recovery than their counterparts. ^[54] Currently, artificial cervical disk replacement is only offered for 1 level disk disease. Artificial disk replacement at 2 level disease is being performed in Europe but is considered investigational in the United States.

Of note, the number of geriatric patients seeking surgical treatment for cervical spondylotic myelopathy is steadily increasing. One study demonstrated that corrective surgical techniques could be performed in patients older than 70 years, with acceptable risk of morbidity and reasonable expectation for clinical improvement. ^[55]