Cervical Disc Disease Treatment & Management

Physical Therapy

For most cervical disc disorders, studies support conservative treatment, such as the McKenzie approach and cervicothoracic stabilization programs, combined with aerobic conditioning.

The McKenzie system identifies 3 mechanical syndromes, as follows, that cause pain and compromise function:

• The postural syndrome provokes pain when normal soft tissues are loaded statically at end ROM; pathology need not be present. Treatment aims to correct posture.

• The dysfunction syndrome produces pain when the patient, upon attempting full movement, mechanically deforms contracted scarred soft tissue. Consequently, therapy involves stretching and remodeling of such contracted tissue.

• The derangement syndrome produces intermittent pain when certain movements or postures occur. Specifically, pain may become centralized or peripheralized because of theoretical activity-dependent displacement of intradiscal material. Therapy attempts to correct derangement by promoting activity that centralizes pain.

The McKenzie theory recognizes that although patients may demonstrate similar signs and symptoms, one movement (eg, cervical extension) nevertheless may help some patients and aggravate symptoms in others. Indeed, McKenzie therapy does not use only extension-biased exercise. Consequently, treatment individualization and patient education play key roles.

Cervicothoracic stabilization limits pain, maximizes function, and prevents further injury. Such stabilization includes cervical spine flexibility, postural training, and strengthening. This program emphasizes patient responsibility through active participation.

Restoring flexibility prevents further repetitive microtrauma from poor movement patterning. Pain-free ROM is determined by placing the cervical spine in positions that produce and relieve symptoms. Initially, stabilization commences within established pain-free ROM and then progresses outside this ROM as pain diminishes. Soft tissue or joint restriction inhibiting ROM is treated quickly. Anterior and posterior neck muscles are stretched. Indeed, such spine and soft-tissue mobilization, passive ROM, self-stretching, and correct posturing collectively restore ROM.

Postural training commences with the patient, supervised by a therapist, in front of a mirror. The patient performs various transfer maneuvers while maintaining a neutral spine (i.e., correct posturing), with feedback from the mirror and the therapist. Patient goals include maintenance of neutral spine and demonstrating correct posture during daily activities.

These proprioceptive skills, implemented during strengthening exercises, facilitate stable, safe, and pain-free cervical posture during strenuous activity. Indeed, cervicothoracic stabilization requires strengthening and coordination of neck, shoulder, and scapular muscles. Cervical muscles include extensors, flexors, rectus capitis anterior, rectus capitis lateralis, longissimus cervicis, and longissimus capitis. Primary thoracic stabilizers include abdominals, lumbar paraspinal extensors, and latissimus dorsi. Scapular muscles include the middle and lower trapezius, serratus anterior, and rhomboids. Chest muscles include the pectoralis major and minor. Successful stabilization also requires the training of the lumbar spine and lower extremities, which provide a foundation for the cervicothoracic spine.

Stabilization exercises proceed systematically from simple to complex. Isometric and isotonic resistive exercises employ elastic bands, weight machines, and free weights. Such conditioning distributes forces away from the cervical spine. Exercise repetition ultimately encodes an engram that commands immediate, automatic cervicothoracic stabilization during everyday activity.

Butler's therapy techniques treat radicular symptoms by mobilizing the involved nerve. First, the therapist identifies "adverse neural tension," defined as pathologic mechanical and physiologic responses elicited from a nerve when its stretch properties and ROM are evaluated. Specifically, the therapist performs neurodynamic testing to evaluate a nerve's mechanical properties (e.g., its mobilization around neighboring intervertebral discs) and physiological characteristics (e.g., its response to ischemia, inflammation). Having tested the nerve in question, the therapist may institute treatment consisting initially of passive mobilization to provide CNS input without inciting a stress response and neurogenic massage to reduce perineural swelling. Later, the therapist progresses to active neuromobilization, because, according to Butler, recovering nervous tissue (like other connective tissue) requires movement to promote healing and restoration of optimum mechanical properties.

Butler admits that limited evidence suggests that neurodynamic mobilization improves clinical outcomes. However, he believes that optimizing tissue health and cardiovascular fitness, as well as minimizing negative beliefs and environmental factors, can be beneficial.

Functional restoration programs assist patients disabled by chronic cervical pain overcome obstacles to recovery. Such obstacles include deconditioning, secondary gain, poor motivation, and psychopathology. An occupational or physical therapist, athletic trainer, or nurse instructs the patient in cervical anatomy, biomechanics, pathology, and ergonomics. Patients employ preventive measures in order to prohibit further injury during all daily activities. These medically directed interdisciplinary programs have been successful at enabling workers' compensation patients to return to work. Furthermore, Wright and colleagues reported lower rates of recurrent injury, new surgery, and need for health care services for patients with chronic cervical pain who successfully completed functional restoration.

An intervertebral disc compressing the spinal cord can provoke myelopathy with associated weakness, hyperreflexia, and neurogenic bowel and bladder dysfunction. Radiculopathy can manifest significant upper limb weakness or numbness. Intractable axial or radicular pain may result from cervical disc disorders.

Studies indicate that cervical HNP with radiculopathy can be managed conservatively. Surgery is warranted when neurogenic bowel or bladder dysfunction, deteriorating neurologic function, or intractable radicular or discogenic neck pain exists. Specifically, cervical spine surgical outcomes are most favorable for radicular pain, spinal instability, progressive myelopathy, or upper extremity weakness. ^[34]

Surgical outcomes for patients with myelopathy have been shown to be significantly greater with regard to motor recovery if surgical intervention is performed less than 1 year after the onset of symptoms. ^[9] A study by Fay et al suggested that cervical arthroplasty is about as effective in treating DDD-related cervical spondylotic myelopathy (CSM) as it is in treating DDD-related cervical radiculopathy. The study involved 151 patients with cervical DDD who underwent arthroplasty, including 72 patients with CSM and 53 with radiculopathy. The investigators found at 3-year postoperative follow-up that the clinical and radiographic outcomes in the myelopathy group were similar to those in the radiculopathy patients. ^[35]

The literature has demonstrated favorable cervical spine fusion outcomes for chronic discogenic axial neck pain when the presurgical evaluation has incorporated provocative cervical discography. Provocative discography identified the painful segment(s) and confirmed adjacent pain-free levels.

Fusion can increase intradiscal pressure and other stress at adjacent unfused levels, thereby accelerating postsurgical spinal degeneration. ^{[10, 11, 12, 13, 14]}

The possibility of obtaining the goals of anterior cervical decompression and fusion (ACDF) while maintaining adjacent segment motion led to the advent of total disc replacement (TDR). Currently, 3 devices for disc replacement have been approved with other trials underway. Studies have shown several advantages of TDR over ACDF, including reduction of bone graft site morbidity, adjacent segment disease, pseudarthrosis, reoperation rate, and anterior cervical plating. ^{[36, 37]}

For example, a literature review by Luo et al comparing TDR (889 patients) to ACDF (837 patients) found that in patients with one-level cervical DDD, TDR led to a significantly reduced rate of adjacent segment disease compared with ACDF, at 24-month postoperative follow-up. ^[38]

In another report, a nonblinded, prospective, randomized, industry-sponsored outcome study with 5-year follow-up (n=209), the rate of reoperation was less following cervical TDR (2.9%) than after conventional anterior cervical discectomy and fusion (14.5%). ^[39]

A prospective, randomized, multicenter, controlled clinical trial by Jackson and Johnson comparing anterior cervical discectomy and fusion with TDR, both performed at two contiguous levels, indicated that TDR produces better long-term results (7 years postsurgery) with regard to neurologic deterioration and adverse events, with range of motion preserved, less neck and arm pain experienced, and fewer subsequent surgeries required. ^[40]

However, disc replacement is not without complications and can lead to implant failure and bone-implant interface failure. Another documented complication is heterotrophic ossification and osteolysis, which can reduce the ROM at the replacement level. To date, no one surgical technique has been found to be statistically more favorable or superior to another. ^{[41, 9, 42, 43]}

A 2009 study sought to determine which factors are predictive of patient outcome following anterior discectomy and fusion. ^[44] Surgical outcomes that developed over a 2-year period were examined in patients who were treated for recalcitrant single-level subaxial radiculopathy or myelopathy. The study's results indicated that important prognostic factors include whether or not a patient is gainfully employed, has normal sensory function prior to surgery, has higher preoperative disability scores, and is involved in spine-related litigation.

A literature review by Joaquim and Riew suggested that multilevel cervical arthroplasty offers at least the same safety and efficacy as anterior cervical discectomy and fusion, with cervical motion preserved and potentially fewer reoperations required. ^[45]

Similarly, in a review of published and ongoing studies, Laratta et al indicated that the clinical outcomes of single-level cervical disc arthroplasty are equivalent to those of anterior cervical discectomy and fusion, while total cost and the need for secondary procedures are reduced. The investigators also reported that the efficacy of two-level cervical disc arthropathy and hybrid surgery may be the same as that of the single-level operation but that the evidence is not yet as strong. ^[46]

A literature review by Hu et al indicated that in the treatment of symptomatic cervical disc disease, the outcome of cervical disc arthroplasty is better than that of anterior discectomy and fusion with regard to overall and neurologic success, Neck Disability Index results, secondary procedures, functional outcomes, patient satisfaction, degeneration of the superior adjacent segment, and serious adverse events related to implants and surgery. ^[47]

A systematic literature review by Wullems et al indicated that percutaneous cervical nucleoplasty is a safe and effective treatment for contained herniated discs, even at long-term follow-up. The investigators cautioned, however, that the level of evidence found in their review was only moderate. ^[48]

See the list below:

• Consultation with an internal medicine specialist is indicated when neck pain suggests an underlying systemic illness (eg, malignancy, infection, metabolic bone disease).

• Consider consultation with a rheumatologist when neck pain suggests a rheumatologic condition (eg, polymyalgia rheumatica).

• Consultation with a surgeon for cervical disc disorders is warranted for resulting neurogenic bowel/bladder dysfunction, deteriorating neurologic status (eg, myelopathy), segmental instability, and/or intractable radicular or discogenic pain.

See the list below:

• Physical modalities should be used to reduce pain only in the acute phase. Once past the acute phase, modalities are used sparingly on an as-needed basis.

  • Superficial heat modalities relax muscle and relieve soft-tissue pain.

  • Conversely, deep-heating modalities (eg, ultrasonography) should be avoided in acute cervical radiculopathy, because they augment inflammation and, consequently, exacerbate radicular pain and nerve root injury.

• Cervical traction may relieve radicular pain from nerve root compression. Traction does not improve soft-tissue injury pain. Hot packs, massage, and/or electrical stimulation should be applied prior to traction to relieve pain and relax muscles.

  • Traction regimens include heavy weight-intermittent or light weight-continuous. The neck is flexed 15-20º (ie, not extended) during traction. In the cervical spine, approximately 10 lb of force is necessary to counter gravity and 25 lb of force is necessary to achieve separation of the posterior vertebral segments.

  • Light weight-continuous home traction is cost effective and provides the patient with more autonomy.

  • Pneumatic traction devices afford greater patient comfort and, consequently, increased compliance.

• A soft cervical collar is recommended only for acute soft-tissue neck injuries and for short periods of time (ie, not to exceed 3-4 days' continuous use). Risks include limiting cervical ROM and losing neck strength if the collar is worn continuously for longer periods.

  • When worn for radiculopathy caused by foraminal stenosis, the wide part of the collar is placed posteriorly and the thin part is placed anteriorly to promote neck flexion, discourage extension, and open the intervertebral foramina.

  • Collars can be worn during certain activities, such as sleeping or driving, for longer periods.

  • Although not commonly used, a Philadelphia collar can be worn at night to position the neck rigidly in flexion, thereby maintaining open foramina.

• Spinal manipulation and mobilization may restore normal ROM and decrease pain; however, no clear therapeutic mechanism of action is known. Some believe that zygapophysial joint adjustment improves afferent signals from mechanoreceptors to peripheral and central nervous systems.

  • Normalization of afferent impulses improves muscle tone, decreases muscle guarding, and promotes more effective local tissue metabolism. These physiologic modifications subsequently improve ROM and pain reduction.

  • Studies document short-term improvement in the acutely injured patient and in those with cervicogenic headache and radiculopathy secondary to disc herniation.

  • No evidence exists that manipulation confers long-term benefit, improves chronic conditions, or alters the natural course of the disorder.

• Cervical epidural, spinal nerve (or root), Z-joint, and sympathetic injections serve diagnostic and therapeutic roles. These procedures can be instrumental in determining the anatomic pain generator (eg, nerve root, facet) and providing aggressive, conservative treatment.

• Therapeutic cervical epidural injections treat radicular pain, although some literature has demonstrated reduced axial pain as well. (See the images below.)

  Right C7 cervical transforaminal epidural steroid injection demonstrating epidural and radicular spread of radiologic contrast dye.

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  Cervical epidural steroid injection at the C7-T1 interlaminar space.

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  See the list below:

  • An anesthetic and corticosteroid mixture may be injected into the epidural space (interlaminar) or along the nerve root (transforaminal) after precise radiologic, contrast-enhanced fluoroscopic localization. ^[8]

  • The anesthetic can relieve sympathetically mediated pain.

  • The corticosteroid provides long-term relief if pain results from an intense inflammatory component.

  • Such injections provide a pain-free window of opportunity for more aggressive physical therapy.

• Diagnostic selective spinal nerve or ventral ramus blocks inject a small anesthetic volume extraforaminally at a single spinal segment level (eg, C5 versus C6); consequently, they are more precise than the "gunshot" interlaminar approach in identifying the symptomatic nerve.

  • Precise symptomatic nerve identification permits the physician to design a more focused treatment protocol.

  • Patients record pain changes in a pain diary following the injection, to confirm diagnostic accuracy.

  • A double injection paradigm previously reported in the literature for facet injections can provide information to the physician for use in determining a diagnosis of radicular pain and to help confirm the symptomatic nerve level. This paradigm identifies patients who have tested false-positive or may have a tendency to respond to a placebo, by determining whether, on separate injection days, they received short-term relief with a short-acting anesthetic (eg, lidocaine) and long-term relief with a long-acting anesthetic (eg, bupivacaine).

• Adverse effects include those from anesthesia, corticosteroids, and radiologic contrast dye.

  • Blood clotting parameters should be drawn prior to injection in patients with suspected bleeding diathesis. Indeed, spinal cord compression could result if bleeding occurs in the presence of relative spinal stenosis (ie, midsagittal diameter less than 12 mm) in which little room exists to accommodate an epidural hematoma.

  • Nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, should be discontinued prior to the procedure in accordance with their half-life and hematologic profile.

  • Other potential risks include seizure, vertebral artery spasm, infection, temporary quadriparesis from anesthetic, and respiratory arrest.

  • One study, however, suggested that selective cervical nerve blocks carry low morbidity when performed under contrast-enhanced fluoroscopic guidance.

  • In any event, proper patient monitoring and emergency equipment always should be present.

• Reports of serious CNS complications, including spinal cord injuries and strokes, following cervical transforaminal steroid injections have gained the attention of many practitioners. The mechanism of the injury is believed to be related to the introduction of particulate matter within the corticosteroid preparations, causing occlusion of a vessel.

  • Hodges and colleagues described 2 case reports in which intrinsic spinal cord damage resulted from cervical epidural steroid injection despite fluoroscopic guidance; the patients, because of intravenous sedation, were unable to perceive and report pain and paresthesias from needle-induced spinal cord trauma during the procedure. ^[49]

  • Furman et al demonstrated a relatively high incidence of entering the intravascular space with transforaminal epidural steroid injections. ^[50] They also showed that attempting to use a flash of blood in the needle hub to predict intravascular compromise was 97% specific but only 45.9% sensitive. This article underscored the importance of using fluoroscopy and contrast dye to ensure proper placement of the therapeutic agents. Using a flash of blood in the hub without fluoroscopy cannot reliably predict intravascular compromise.

  • Brouwers et al reported a fatal case of spinal cord infarction following a cervical transforaminal steroid injection. ^[51]

  • Baker et al demonstrated that a radicular artery supplying the cervical spinal cord can be infiltrated by a transforaminal epidural steroid injection. ^[52] In this report, prior to steroid injection for a left C6-C7, contrast was administered. Using digital subtraction technique, it was clear that a radicular artery filled with contrast; the procedure was aborted without adverse effects. This report revealed a potential access point for an injection-related spinal cord infarction.

  • The potentially catastrophic complications that can follow a cervical transforaminal epidural steroid injection cannot be underestimated. While these procedures are perceived as posing less of a risk than surgery, they still carry substantial hazards. They should be performed by skilled practitioners and under fluoroscopic guidance. Baker et al further suggest the use of digital subtraction, because intravascular compromise may be missed on routine spot films. ^[52]

Emerging concepts

Biologic therapies for symptomatic intervertebral discs offer a novel approach to treatment. By effectively targeting the primary pain generator (ie, the intervertebral cervical disc) clinicians may treat the source of the pain and not just the sequelae of the degenerative cascade (ie, radiculopathy or discogenic pain). These treatments may also offer alternatives to conservative or surgical measures. Because these agents can be injected with contrast-enhanced fluoroscopic guidance, they may result in reduced morbidity to the patient.

To date several biologic compounds are under clinical and laboratory investigations. These include:

• Growth factors, including tumor growth factor (TGF)-beta, bone morphogenetic proteins (BMP)-2, BMP -7, BMP-14: Infusion of growth factors has been shown in animal models to cause an anabolic response with increases in disc height and proteoglycan synthesis. BMP-7 and BMP-14 are currently in phase I clinical trials.

• Gene transfer: The gene encoding the growth factor or therapeutic protein would be implanted into the disc to produce the protein in situ. Preliminary results have been promising, showing increased proteoglycan synthesis when injected into human disc cells in vitro. ^[53]

• Cell therapy, including autologous disc cells, articular chondrocytes, and mesenchymal stem cells: These substances can be transplanted into vertebral discs, slowing disc degeneration. Several in vivo animal studies have shown that mesenchymal stem cells slow the progression of disc degeneration as well as regenerate the matrix. ^[54] Numerous other studies have demonstrated the ability of injected cells to survive, differentiate toward disc cells, and produce matrix components, including collagen II and proteoglycans. ^{[53, 54]}

• Tissue engineering: Therapeutic agents, when injected into the intervertebral disc function to alter both biochemical and biomechanical stressors. At this time, a US Food and Drug Administration (FDA)-approved trial is underway evaluating the efficacy and safety of a fibrin sealant derived from human plasma derivatives (fibrinogen and thrombin). This substance (fibrinogen and thrombin) has been shown in animal studies to inhibit nucleus pulposus fibrosis, promote recovery of proteoglycan content, and facilitate repair of the annulus. A pilot study showed reduction in pain and disability at 1 and 2 years after a single injection. ^{[55, 56]}

In the early stage of disc degeneration, protein factors such as growth factors and proteinase inhibitors may be effective. In the intermediate stage of degeneration, cell or gene therapy may be required. In the advanced stages of disc degeneration, tissue engineering approaches will be needed.

Biologic substances offer a great potential for therapy of the degenerative disc. There have been numerous studies indicating in vitro and in vivo success in rebuilding or repairing the structure of the intervertebral disc. With these rapid advancements, these interventions may soon be available in clinical practice. What remains to be answered is if these biomechanical and biochemical alterations will offer clinically relevant findings. Whether structural changes to the disc will lead to decreased pain and increased function of the patient is unclear.