Cervical Degenerative Disc Disease (Including Cervical Disc Herniation)

Abstract

Cervical disc degeneration is a common age-related finding among adults presenting with neck pain, cervical radiculopathies, and myelopathy. The natural history of cervical degeneration leads to decreased disc height, facet hypertrophy, and potential loss of volumetric area of the spinal canal and foramen. Clinical assessment, radiographic analysis, and advanced imaging are critical in establishing a diagnosis helping to support treatment modality decisions. Nonoperative and operative pathways for patients with cervical disc degeneration depend on the offending pathology and the degree of neurologic compression.

1 Definition

Cervical degenerative disc disease refers to age-related changes within the intervertebral disc space typically found in tandem with the facet and uncovertebral joint degeneration resulting in spondylosis. Symptoms of cervical spondylosis manifest as axial neck pain, radiculopathies, and cervical myelopathy.

2 Natural History

Cervical disc degeneration is common among patients presenting with axial neck pain and upper extremity symptoms, especially within the elderly population. Loss of cervical disc height results in bulging of the annulus, infolding of the ligamentum flavum, and facet hypertrophy reducing the volumetric area of the spinal canal and foramen. Disc desiccation and collapse occur concomitantly with facet arthrosis contributing to focal and multifocal cervical spondylosis. Structural changes within disc’s proteoglycan typically occur within the third decade of life diminishing the hydration of the disc; specifically, keratin sulfate increases and chondroitin sulfate decreases altering the viscoelasticity [1]. Focal and multilevel disc degeneration can cause neurologic impairment and deformity, most commonly with progressive loss of cervical lordosis leading to kyphosis. Degenerative changes within the nucleus pulposus and annulus fibrosus predispose patients to disc herniations. Disc degeneration can lead to a cascade of arthritic changes within the intervertebral space, uncovertebral joints, and facets. Neurologic impingement within the cervical spine can manifest as upper extremity radiculopathies, myelopathy, and a combination of both termed myeloradiculopathy.

3 Physical Examination

After a thorough history, the physical exam should entail a comprehensive assessment of the location of pain, gait, neurological exam, and cervical-specific maneuvers. The neurological examination must include a detailed motor exam, assessment of reflexes (Table 42.1), and a sensory exam (Videos 42.4 and 42.9). Motor evaluation should assess upper and lower extremities with the evaluation of each muscle group supplied by its respective nerve root (Table 42.2). Unilateral sensory or motor deficits within a specific nerve root are indicative of a radiculopathy, whereas bilateral weakness or sensory disturbances, hyperreflexia, gait instability, and pathologic reflexes are more commonly found in the setting of myelopathy. Spurling’s test, head in extension and lateral bending with applied axial compression, and Lhermitte’s sign, “shock-like” sensation with passive cervical flexion, are a few examples of sensitive exam maneuvers delineating cervical radiculopathy and myelopathy, respectively. Additional exam findings, such as Hoffman’s and Babinski signs, provide further insight on the impact of the offending pathology and are useful in gaining a thorough understanding of the patient’s neurologic status.

Table 42.1 Reflexes

Table 42.2 Myotomes

4 Imaging

Radiographic imaging of the cervical spine is a quick and cost-effective initial study for patients presenting with neck pain, radiculopathy, and myelopathy (Chap. 43). Radiographs can offer critical assessments of alignment, degree of spondylosis, and/or possible trauma. Anterior-posterior and lateral views provide a static understanding of the state of the cervical spine; supplementary views in flexion and extension can be beneficial when there is a concern for dynamic instability. Additionally, radiographs are useful in the initial assessment of disease states such as diffuse idiopathic skeletal hyperostosis (DISH) (Fig. 42.1) (Chap. 54) and ossification of posterior longitudinal ligament (OPLL) (Fig. 42.2), which are better defined with computed tomography (CT). CT is the imaging of choice to assess bony architecture providing granular information on fused or potentially fused intervertebral segments and compressive osseous pathology. Magnetic resonance imaging (MRI) is an excellent imaging modality to assess neural elements, intervertebral disc, and ligamentous structures and is highly sensitive at detecting degenerative changes, such as bulging discs and cervical spondylosis. It is important for providers to recognize the high prevalence of degenerative changes on MRI among asymptomatic patients. Therefore, it is imperative that diagnostic imaging be utilized as an adjunct to the history and clinical examination.

Fig. 42.1

Diffuse idiopathic skeletal hyperostosis (DISH)

Fig. 42.2

Ossification of posterior longitudinal ligament (OPLL)

5 Treatment Options

Cervical degenerative disc disease is a continuum from focal disc herniation leading to radiculopathy and/or myelopathy to multilevel cervical degeneration causing sagittal malalignment. Treatment plans should be individually tailored targeting clinically relevant pathology in order to optimize outcomes. Patients with cervical myelopathy commonly present with stepwise deterioration intermixed with static periods of unchanged symptoms. Overall prognosis is highlighted by progressive compression and dysfunction of the spinal cord leading to gradual deterioration in functional status over time. Surgical intervention, in the form of decompression with possible fusion, is commonly required to halt the progression of disease and preserve function. Non-myelopathic cervical patients, specifically those presenting with radiculopathies, typically have a favorable prognosis with the majority noting improvement with nonoperative care. Nonoperative treatment modalities for cervical radiculopathies include nonsteroidal anti-inflammatory drugs, oral corticosteroids, and cervical steroid injections. Surgeons should consider the constellation of preoperative symptoms, including the degree of spinal cord dysfunction, duration of symptoms, and general health of the patient, prior to proceeding with surgery. Surgical treatments primarily focus on decompression of neurologic elements with possible fusion if there is a disruption of the spinal column. Situations addressing sagittal malalignment may require osteotomies with multilevel instrumentation and arthrodesis. Specific treatments of degenerative disc disease, such as anterior cervical discectomy and fusion (ACDF) or cervical laminectomy and fusion (Videos 42.2 and 42.7), are predicated on the location of compression and the surgeon’s decision regarding optimal construct.

6 Expected Outcomes and Potential Complications

Goals of intervention in the setting of degenerative disc disease are twofold, decompression of the spinal cord and/or roots and maintenance or reestablishment of normal sagittal alignment. Typically, successful surgical outcomes are more common among patients with duration of symptoms less than 1 year, younger age at presentation, pathology limited to fewer vertebral segments, and the presence of unilateral symptoms. Results of anterior cervical surgery are highly favorable both in terms of providing durable relief of symptoms and rates of fusion. Although fusion rates tend to decrease with multilevel ACDFs, these surgeries, when performed on appropriately selected patients, are highly reliable treatment options for cervical radiculopathy and myelopathy. Posterior decompression and/or fusion is considered for patients with multilevel cervical myelopathy, OPLL, kyphotic deformities, or congenital stenosis. Laminoplasty, laminectomy alone, and laminectomy and fusion offer a variety of surgical options in treating multilevel disease while achieving neurologic decompression. Surgeons should consider preoperative cervical global alignment prior to performing a posterior-only decompression since kyphotic alignment is associated with poor outcomes. Additional consideration should be given to those patients at risk of developing post-laminectomy kyphosis. Combined anterior and posterior surgeries are thought to provide rigid stabilization through a circumferential fusion affording surgeons correction of alignment and decompression of the spinal cord. These surgeries tend to entail greater blood loss, longer operative times, and overall increases in morbidity.

7 What Should Patient and Family Know?

Degenerative changes within the cervical spine are consequences of aging with the majority of the population remaining asymptomatic. Patients with cervical disc degeneration and spondylosis present with a myriad of symptoms most commonly grouped as radiculopathies, myelopathies, and/or axial neck pain. A thorough knowledge of the natural history of disease and determining the level of pathology through clinical findings and advanced imaging are critical in determining ideal treatments. Treatment of radiculopathy is centered around nonsurgical interventions with surgical decompression and stabilization reserved for those with persistent symptoms despite conservative measures. Clinically evident myelopathy requires close monitoring and possible surgical intervention to prevent the progression of disease and maintain functional status.