Cervical disc degeneration becomes higher priority in light of aging population

In our virtual round table, participants discuss treatment options and the ideal cases for surgery.

Although cervical disc degeneration is often referred to as a disease, it is really a process of normal aging. In the early stages of degeneration, the intervertebral disc loses water content and can appear dark on T2-weighted MRI. This phenomenon is commonly referred to as a “dark disc.” Further degeneration can lead to loss of disc height, uncovertebral joint hypertrophy, osteophyte formation, annular weakening and disc herniation. Patients with disc degeneration can develop radiculopathy from foraminal stenosis, disc herniation or a combination of both.

The pathogenesis of cervical radiculopathy is believed to occur from the inflammatory process initiated by nerve root compression. This mechanical irritation may be the result of several physiologic processes. These include direct nerve root compression due to a soft disc herniation, neuroforaminal stenosis resulting from osteophyte formation or disc space narrowing, or excessive motion or instability at the intervertebral disc level.

Most patients with cervical radiculopathy will improve with nonoperative measures, including nonsteroidal anti-inflammatory medications, physical therapy and traction. Surgery is reserved for patients with persistent pain, numbness, and/or weakness that have failed conservative treatment.

Philip S. Yuan, MD
Moderator

Round Table Participants Moderator Philip S. Yuan, MD Memorial Orthopaedic Surgical Group, Long Beach, CA Amir H. Fayyazi, MD assistant professor of orthopedics, Institute for Spine Care, SUNY Medical Center Syracuse, NY Stephen J. Timon, MD clinical assistant professor, Department of Orthopaedic Surgery, University of Texas at Southwestern, Dallas, TX Alexander R. Vaccaro, MD, FACS professor, Department of Orthopaedic and Neurosurgery, Thomas Jefferson University and the Rothman Institute, Philadelphia, PA

Philip S. Yuan, MD: What is your preferred surgical method to treat cervical radiculopathy due to a soft disc herniation?

Alexander R. Vaccaro, MD, FACS: Surgical intervention in the setting of symptomatic cervical radiculopathy has four goals:

• to decompress the nerve root and eliminate irritation;
• to distract the interspace indirectly to relieve nerve root compression;
• to alleviate dynamic nerve root compression; and
• if possible, to alleviate neck pain.

There are several surgical options for treating cervical radiculopathy. These include an anterior foramintomy (ie, uncinectomy), an anterior cervical discectomy, an anterior cervical discectomy and fusion, and a posterior foraminotomy. My choice generally is an anterior cervical decompression and fusion (ACDF) due to the excellent visualization of any offending compressive lesion, the lack of manipulation of neural elements as well as the ability to stabilize the interspace, (ie, fusion, in order to relieve dynamic irritation. It is unclear if a solid fusion leads to the regression of osteophytes but it may have the benefit of relieving dynamic nerve root irritation. This may also help in alleviating neck discomfort although this is a less consistent outcome as compared to arm pain relief.

Stephen J. Timon, MD: Soft disc herniation is a common entity in the fourth, fifth and sixth decades of life. It often presents with axial neck pain as well as upper extremity radiculopathy. Initial treatment usually begins with rest and NSAIDs. Cases refractory to this often will require physical therapy and epidural steroid injections. Many cases will resolve with these treatments, yet a significant proportion will not. After nonoperative modalities fail, surgery becomes an option.

“I think selective nerve root blocks are valuable tools in the treatment of cervical radiculopathy.” — Stephen J. Timon, MD

Anterior cervical discectomy and fusion has long been the standard in treatment of soft disc herniations in the cervical spine. The principle benefit of the procedure is direct visualization of the disc herniation and the neural structures. If the posterior longitudinal ligament is removed, the spinal cord is in the surgeon’s direct line of vision and decompression can be assured. I feel that this is the most important benefit of this approach.

Secondary benefits of the procedure are that the surgeon can perform the approach through an intermuscular plane (except the platysma). He can perform fusion using this approach without increased exposure, and he can restore disc height and indirectly increase foraminal size. Although no procedure is without its drawbacks (ie, injury to the esophagus, trachea, recurrent laryngeal nerve and vertebral artery), this technique has shown good to excellent results in as much as 93% of patients.

Amir H. Fayyazi, MD: Cervical radiculopathy often results from nerve root compression due to a soft disc herniation (herniated nucleus pulposus), and is associated with pain, paresthesia and weakness. My preferred treatment for a soft disc herniation is posterior cervical foraminotomy, which has been shown to be safe and effective. Recent technical developments now allow a minimally invasive approach with even lower morbidity and faster recovery.

Unlike ACDF, posterior foraminotomy is a motion-sparing procedure with good to excellent long-term follow-up and a very low rate of same-segment disease (ie, 5% prevalence in 10 years) and a potentially lower rate of adjacent-segment disease (6.7% prevalence in 10 years) when compared to ACDF (16% to 25% prevalence in 10 years). Finally, unlike ACDF, posterior foraminotomy does not require bone graft incorporation, and the result is not diminished by the presence of a pseudarthrosis.

“I do believe that there is a role for these devices in treatment of cervical pathologies, especially in the presence of the multiple-level disease.” — Amir H. Fayyazi, MD

Yuan: I would agree with all of the above. If a patient has pure radicular symptoms in the setting of a soft cervical disc herniation, both anterior discectomy with fusion and posterior foraminotomy are viable options. I would agree with Dr. Timon, that the anterior approach is better tolerated by patients, and even a small posterior incision can actually cause neck pain. When the patients have a significant amount of neck pain, I usually recommend an anterior decompression and fusion because I think the fusion may improve their neck pain. In my hands, I feel I can perform a better decompression from the front, both by directly decompressing the spinal cord and exiting nerve roots, as well as indirectly by distracting the disc space and neuroforamen. The main advantages of a posterior foraminotomy are preservation of motion, a faster recovery and return to activities, a decreased risk of injury to the anterior structures of the neck (ie, esophagus, recurrent laryngeal nerve, carotid artery, etc.), and a decreased risk of adjacent segment degeneration.

Yuan: Do you recommend selective nerve root blocks (epidurals) to patients with cervical radiculopathy?

Timon: I think selective nerve root blocks are valuable tools in the treatment of cervical radiculopathy. These injections can be both diagnostic and therapeutic. Too often we encounter patients with multilevel cervical disease and radiculopathy that does not follow classic dermatomes and myotomes. These patients can be a diagnostic dilemma.

Interlaminar steroid injections can provide relief over multiple levels. Selective nerve root blocks will specify a nerve, and the therapeutic results will help in decision-making.

There have been a number of occasions in which a single selective nerve root block resulted in complete relief in patients who I would have expected to have residual symptoms. These patients, who ultimately had a single-level anterior cervical discectomy and fusion, went on to have excellent results.

Vaccaro: I rarely recommend selective nerve root blocks. I only do so in the rare instance of persistent arm discomfort in the setting of multilevel foraminal stenosis where I am unclear as to the exact cause of arm pain. In this setting, I am doing this for diagnostic rather than therapeutic reasons.

I may also consider obtaining an EMG to rule out peripheral nerve root entrapment or possibly a neuropathy. If there is an obvious compressive lesion, such as a posterior lateral disc herniation, I will avoid the cost and possible morbidity related to this procedure, and treat this patient with physical therapy and anti-inflammatory medication.

Fayyazi: The use of selective nerve root injection in the treatment of cervical radiculopathy is controversial. There is very little evidence that the steroid injection results in long-term improvement or that it prevents surgical intervention in patients suffering from cervical spondylotic radiculopathy.

Despite this, I do use the selective nerve root block extensively in my practice as a diagnostic tool when there is a discrepancy between the clinical presentation and the radiographic finding. In these cases, the cervical selective nerve root block has been shown to be effective in distinguishing symptomatic levels from asymptomatic levels.

There may also be a role for these injections as a temporizing measure in patients who present acutely with a soft disc herniation and severe radiculopathy, given the fact that many cervical disc herniations can be successfully managed with aggressive nonsurgical treatment with good to excellent outcomes. In these patients, a selective nerve root block may provide a temporary relief of the acute pain and prevent surgical intervention.

“I have never done a cervical laminectomy without a fusion for fear of postlaminectomy kyphosis.” — Philip S. Yuan, MD

Yuan: I recommend selective nerve blocks to many of my patients with cervical radiculopathy. I am fortunate to have a local pain-management specialist, who is well trained in these injections. None of my patients have had any complications, and several have had excellent relief of their pain. Epidurals can often ease the severe pain associated with acute radiculopathy. It has eliminated the need for surgery in some of my patients who were begging for surgery. I also find them to be helpful diagnostically, especially in cases of multilevel neuroforaminal stenosis.

Yuan: Do you feel there is a role for disc arthroplasty in the cervical spine? If so, who would be the ideal patient?

Fayyazi: Cervical disc arthroplasty devices are currently under investigation and will soon be available in this country for treatment of cervical spondylotic radiculopathy. The available cervical disc devices do differ greatly in their design, but are similar in that they are all designed to allow motion at the operative level and potentially decrease the rate of adjacent segment disease. Although, patients who suffer from cervical disc disease are prone to have progression of disease at other segments, there is some evidence that fusion increases the stress, strain and intradiscal pressure of the adjacent level and potentiates the adjacent segment degeneration.

I do believe that there is a role for these devices in treatment of cervical pathologies, especially in the presence of the multiple-level disease. The ideal patient for cervical disc replacement is one who suffers from one- or two-level cervical radiculopathy, has failed conservative treatment, is contemplating anterior cervical discectomy and fusion, and does not suffer from facet disease, cervical myelopathy or metal allergies.

In the future, the role of these devices may be extended to treatment of spondylotic neck pain and in patients with greater than two-level involvement; however, there are very little postoperative data available on these patient groups at this time.

Timon: We are fortunate as spine surgeons to experience and utilize the advances of motion-preservation technology. The advances over the past five years have been significant in both the lumbar spine and the cervical spine. However, I feel that the role for disc arthroplasty in the cervical spine is currently limited. Surgeons have long debated adjacent-level spondylosis in the cervical spine. Is it a consequence of adjacent-level fusion? Is it the natural progression of spondylosis and osteoarthritis itself?

Why do some people have multilevel degeneration? Why do some people only have single-level degeneration? Will they progress to multilevel disease without any intervention? These are important questions that we must ask ourselves before we select new modalities for treating cervical spine disorders.

Currently, ACDF has been the dominant method for treating spondylosis and herniated nucleus pulposus in the cervical spine, yielding excellent results. Early results for disc arthroplasty have yielded inferior results. Spontaneous fusion has regularly occurred, as well as fibrous nonunions, resulting in continued pain.

What will happen in the cervical spine with implant failure? Commonly, the thought process is that a young patient with single-level disease is the ideal candidate for disc arthroplasty.

Yet, this patient is the one with the highest likelihood of success with ACDF. We have made many strides in the area of motion preservation, but it as it stands now, disc arthroplasty has inferior results compared to the current standard of care, and its implementation should be used with caution.

Yuan: I also feel that cervical arthroplasty may eventually have a place in the treatment of cervical disc degeneration. It will be difficult to improve outcomes over anterior cervical discectomy and fusion, where good to excellent results occur in over 90% of patients with single-level disease.

However, for two- and possibly three-level disease, I feel that cervical arthroplasty will eventually prove to be superior to fusion by maintaining motion, decreasing neck pain and decreasing the rate of adjacent-segment degeneration. I believe that cervical arthroplasty will ultimately prove to be more effective than lumbar disc replacement in the treatment of spondylosis.

Vaccaro: I believe cervical arthroplasty is equivalent in outcomes to a single-level disc fusion in properly selected patients. It may have a benefit over fusion, although at this time it is unproven in the management of a patient with two-level disease in which only one level is symptomatic. In such a case, the surgeon may wish to theoretically minimize junctional stresses on the unfused level by performing a single-level arthroplasty, rather than a fusion. The perfect candidate for a cervical arthroplasty would be a patient with single-level disease in the absence of any significant neck discomfort, with radiographic evidence of junctional disease.

Yuan: Cervical spondylotic myelopathy (CSM) typically results from spinal cord compression due to disc herniation, ligamentum flavum hypertrophy, osteophyte formation, or ossification of the posterior longitudinal ligament (OPLL). As people continue to live longer, spine surgeons will see more and more patients with symptomatic cervical stenosis. We all are aware that anterior decompression and fusion is indicated in a kyphotic cervical spine, but most people prefer a posterior approach for multilevel stenosis in a straight or lordotic spine.

Yuan: Do you prefer laminoplasty or laminectomy and fusion for the treatment of multilevel cervical stenosis (eg, myelopathy)?

Fayyazi: Laminoplasty and laminectomy with fusion are both valid options for treatment of multilevel cervical spondylotic myelopathy. Both procedures allow decompression of the spinal canal and are very effective in treating this patient population.

“It is a misconception that laminoplasty preserves motion, since most studies show that individuals lose between 20% and 40% of their range of motion with a laminoplasty procedure.” — Alexander R. Vaccaro, MD, FACS

I do prefer the use of laminoplasty, since this procedure allows for expansion of the spinal canal without compromising the stability of the cervical spine while preserving the motion. The range of motion following laminoplasty is diminished postoperatively. Despite this, the preservation of subaxial motion may prevent adjacent segment degenerative changes. Unfortunately, laminoplasty is contraindicated in the majority of our patients due to the presence of kyphotic deformity or instability. Furthermore, patients who suffer from significant preoperative neck pain should be carefully evaluated prior to a laminoplasty procedure and may have a better outcome with a fusion procedure.

Yuan: I prefer laminectomy and fusion. I have never done a cervical laminectomy without a fusion for fear of postlaminectomy kyphosis. I have not noticed a significant loss of motion in these patients, even with four- to five-level fusions, because these patients really don’t have much motion preoperatively. Furthermore, we all know that about 50% of cervical motion occurs between the occiput and C2. Fusion rates approach 100% in these patients when we use locally harvested autograft alone, and it often helps any neck pain the patient may have had.

Timon: Despite my preference for the motion preservation, the majority of my patients do not qualify for laminoplasty. The presence of kyphotic deformity or instability is a direct contraindication for laminoplasty. Furthermore, patients who do suffer from significant preoperative neck pain should be carefully evaluated prior to a laminoplasty procedure and may have a better outcome with a fusion procedure. Both laminoplasty and laminectomy and fusion are valuable tools for the treatment of multilevel cervical stenosis. They each have their appropriate indications and are readily used. The limitations of laminoplasty are based on the sagittal contour of the cervical spine. Although, this is commonly recommended in treatment of multilevel cervical stenosis with lordotic or neutral sagittal contour, the results tend to be better with a lordotic posture.

Patients with axial neck pain tend to improve with laminectomy and fusion. The downsides of laminectomy and fusion: extra time to heal, and the pseudarthrosis rate.

I feel that surgeon preference is ultimately based on the patient to be treated and the surgeon’s comfort with procedures like laminoplasty. These are both valuable techniques in the treatment of cervical stenosis.

Vaccaro: I prefer to perform a laminectomy and fusion for the treatment of multilevel cervical stenosis in the setting of myelopathy for several reasons. It is a misconception that laminoplasty preserves motion, since most studies show that individuals lose between 20% and 40% of their range of motion with a laminoplasty procedure. This may result in junctional changes above or below a fusion.

It is theoretically possible that the laminaplasty hinge may close down in certain techniques, resulting in recurrence of symptoms. I am also unsure if a reliable decompression of the foramen is performed on the hinged side. Patients who undergo a laminoplasty procedure often have noticeable neck discomfort in the perioperative period (from 10% to 50%). I find this to be less of a problem following a fusion, especially in the setting of posterior facet disease.

Laminoplasty should not be performed in the setting of a straight or slightly kyophotic neck due to the possibility of perioperative instability of kyphosis. Most authors recommend the presence of at least 10° of lordosis before performing the procedure. A segmental posterior instrumentation fusion can improve and maintain cervical lordosis. Cervical laminectomy and fusion is also a less challenging procedure, with a record of satisfactory outcomes in most surgeons’ hands. In the setting of myelopathy, stretch-induced apoptosis may be a significant cause of neurologic dysfunction, which may theoretically worsen with a procedure that preserves motion (ie, laminaplasty). Finally, the potential for a C5 nerve root palsy may be slightly increased following a laminoplasty compared to a posterior decompression and fusion.

For more information:

• Anderberg L, Annertz M, Brandt L, et al. Selective diagnostic cervical nerve root block — correlation with clinical symptoms and MRI-pathology. Acta Neurochir (Wien). 2004;146:559-565; discussion 65.
• Anderberg L, Annertz M, Persson L, et al. Transforaminal steroid injections for the treatment of cervical radiculopathy: a prospective and randomised study. Eur Spine J 2006.
• Chiba K, Toyama Y, Watanabe M, et al. Impact of longitudinal distance of the cervical spine on the results of expansive open-door laminoplasty. Spine 2000;25:2893-2898.
• Clarke MJ, Ecker RD, Krauss WE, et al. Same-segment and adjacent-segment disease following posterior cervical foraminotomy. J Neurosurg Spine. 2007;6:5-9.
• Fujimura Y, Nishi Y, Nakamura M. Dorsal shift and expansion of the spinal cord after expansive open-door laminoplasty. J Spinal Disord. 1997;10:282-287.
• Herkowitz HN. Cervical laminaplasty: its role in the treatment of cervical radiculopathy. J Spinal Disord. 1988;1:179-88.
• Hilibrand AS, Robbins M. Adjacent segment degeneration and adjacent segment disease: the consequences of spinal fusion? Spine J. 2004;4:190S-194S.
• Hirabayashi K, Satomi K. Operative procedure and results of expansive open-door laminoplasty. Spine. 1988;13:870-876.
• Hirabayashi K, Toyama Y, Chiba K. Expansive laminoplasty for myelopathy in ossification of the longitudinal ligament. Clin Orthop Rel Res. 1999:35-48.
• Holly LT, Moftakhar P, Khoo LT, et al. Minimally invasive 2-level posterior cervical foraminotomy: preliminary clinical results. J Spinal Disord Tech. 2007;20:2024.
• Ishihara H, Kanamori M, Kawaguchi Y, et al. Adjacent segment disease after anterior cervical interbody fusion. Spine J. 2004;4:624-628.
• Morimoto T, Matsuyama T, Hirabayashi H, et al. Expansive laminoplasty for multilevel cervical OPLL. J Spinal Disord. 1997;10:296-298.
• Puttlitz CM, DiAngelo DJ. Cervical spine arthroplasty biomechanics. Neurosurg Clin N Am. 2005;16:589-594, v.
• Robertson JT, Papadopoulos SM, Traynelis VC. Assessment of adjacent-segment disease in patients treated with cervical fusion or arthroplasty: a prospective 2-year study. J Neurosurg Spine. 2005;3:417-423.
• Saal JS, Saal JA, Yurth EF. Nonoperative management of herniated cervical intervertebral disc with radiculopathy. Spine. 1996;21:1877-1883.
• Sasso RC, Macadaeg K, Nordmann D, et al. Selective nerve root injections can predict surgical outcome for lumbar and cervical radiculopathy: comparison to magnetic resonance imaging. J Spinal Disord Tech. 2005;18:471-478.
• Satomi K, Nishu Y, Kohno T, et al. Long-term follow-up studies of open-door expansive laminoplasty for cervical stenotic myelopathy. Spine. 1994;19:507-510.