Discogenic Neck Pain

Timothy A. Garvey

Smith and Robinson described anterior cervical discectomy and fusion (ACDF) as a treatment option for cervical disk degeneration in patients suffering from a cervical disk syndrome. This syndrome featured chronic pain in the dorsal aspect of the neck, shoulder, occiput, and arm; paresthesias in the arm; limitation of movement of the neck; and roentgenographic evidence of cervical disk degeneration (1, 2 and 3). This description appears to encompass the continuum of pain symptoms that can be generated from a cervical motion segment. This includes axial mechanical localized neck pain, referred symptoms ranging from the occiput to the interscapular region, and radicular pain into the upper extremity along the course of the ventral rami. In patients with radicular pain and objective neurologic compression or loss of neurologic function, whether radicular or myelopathic, there is little controversy about the validity of ACDF as a treatment option (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24). The focus of this chapter is on patients who have localized neck pain, with or without referred symptoms, as their chief complaint, who present for evaluation of potential surgical options. The goal is to provide an understanding of the surgical literature that affects rational decision making regarding the surgical option for such patients.

EPIDEMIOLOGY

Although another chapter in this textbook details the epidemiology of the degenerative process, a brief review of neck pain is useful. Bovim et al. (25) reported on a prevalence study in which 35% of the general Norwegian population reported neck pain complaints within the previous year. Fourteen percent of the respondents reported that their neck pain lasted more than 6 months. A similar population-based study in Finland noted that about 9.5% of men and 13.5% of women reported a chronic neck pain syndrome (26). A more recent report by Cote on the Saskatchewan Health and Back Pain Survey revealed that 54% of respondents experienced neck pain in the previous 6 months; almost 5% of these respondents perceived their neck pain as highly disabling (27). It appears, therefore, that neck pain of some magnitude, with a minority of about 5% to 10% of cases being severe or chronic in nature, may affect the general human population.

NATURAL HISTORY

Although most of those with neck pain complaints noted in questionnaire studies likely do not present for medical evaluation, many patients do so. We have an appreciation for the natural history of these cases. Gore reported on the long-term follow-up of 205 patients with neck pain (28). In this study with, an average 15.5-year follow-up, nonoperative management led to 79% of patients noting improvement, with 43% being pain free and 32% having moderate to severe persistent pain (28). Specific injury and severity of initial symptoms were reported to be more indicative of an unsatisfactory outcome.

Rothman, a nonadvocate of surgical intervention in those with axial cervical spine pain, stated, “It does not appear that cervical disk degeneration is a brief selflimiting disorder, but rather a chronic disease, productive of significant pain and incapacity over an extended period of time” (29). DePalma and Subin (30) reported on a series of patients with neck or neck and radicular pain of which only 45% of those treated nonoperatively had a satisfactory long-term outcome. DePalma et al. (9) reported on another series of patients with significant cervical disk degeneration, dominant neck pain, and no gross radiculopathy; in these patients, nonoperative care led to complete relief in 21%, partial relief in 49%, and no relief in 22% at 3 months of follow-up. Rothman noted at a 5-year follow-up study that 23% of patients who had significant cervical symptoms from disk degeneration remained partially or totally disabled (20). However, in the surgical group treated for dominant neck pain, little functional difference was noted at the 5-year point, which led to his adopting a “most conservative posture in the treatment of the nonneurogenic syndromes” (20).

Lees in the 1960s (31) and Dillin in the 1980s (32) reported on the natural history and prognosis of cervical radiculopathy. Their work demonstrated that radiculopathy typically does not progress to myelopathy but that in almost two-thirds of those treated nonoperatively, there is persistent symptomatology (although not severe in all).

It thus seems that as a ballpark estimate for the education of a patient seeking consultation regarding treatment options, natural history studies would predict a minority of about 20% to 30% of individuals who present with
complaints referable to cervical degenerative conditions to have persistent symptomatology of moderate to severe enough magnitude to interfere with the activities of daily living. It is in this smaller group that the surgeon needs to evaluate whether surgical management is a viable option.

TRAUMATIC ETIOLOGY

A substantial number of patients who present for surgical evaluation have a specific traumatic event as the initiating factor of their symptoms, whereas for others, a gradual onset would go along with a slowly progressive degenerative disorder. Many patients present with a classic rearend mechanism of injury, that is, a whiplash injury. The Quebec Task Force preferred the terminology whiplashassociated disorder (WAD) in its monograph (33). It concluded that WAD is almost always self-limited and rarely results in permanent harm (33). In their review and methodologic critique of the literature, however, Freeman and colleagues determined, “There is no epidemiologic or scientific basis in the literature for the following statements; whiplash injuries do not lead to chronic pain, rear impact collisions that do not result in vehicle damage are unlikely to cause injury, and whiplash trauma is biomechanically comparable with common movements of daily living” (34).

Ian MacNab, one of the founding members of the Cervical Spine Research Society, summated his experience with whiplash injuries: “about 10-20% are left with discomfort of sufficient severity to interfere with their ability to do work or to enjoy themselves in leisure hours” (35). Although this was more of his gestalt, he specifically commented on a total of 266 patients, of an original 575 group series, 2 years after the settlement of court actions (36,37). Of these 266 patients, 145 were available for review, and 121 had persistence of symptoms. Therefore, a minimum of 45% (121 of 266) of patients 2 years after court settlement had persistence of symptoms.

In Hohl’s 5-year follow-up of 146 patients with soft tissue injuries to the neck, 43% of patients, who had no preexisting degenerative changes, had persistent symptomatology, although no comment as to the magnitude of that symptomatology is given (38).

A continuing series from Bristol has assessed prognostic factors in soft tissue injuries of the cervical spine (39, 40 and 41). At 2 years’ follow-up, 66% of subjects had complaints of neck pain, and 43% had headaches (40). At 10.8 years’ follow-up, Gargan and Bannister (39) noted that residual symptoms were intrusive in 28% and severe in 12%.

Hildingsson and Toolanen (42) reported on a prospective series of 93 patients regarding the outcome of soft tissue neck injuries suffered in car crashes; 42% of patients reported complete recovery, and 58% reported continued symptoms. Of the total 93 patients, 41 (44%) had substantial complaints, whereas 13 (14%) complained of only mild discomfort. Jonsson et al. (43) reported on a prospective 5-year evaluation of 50 patients with whiplashtype neck distortions. Fourteen of 50 (28%) had persistent symptoms, with an average visual analogue score (VAS) of 3.1. Another 6 of 26 (23%) who originally had improved at 6 weeks redeveloped neck symptoms.

Finally, Freeman and coworkers reported on an interesting study of major spinal injury resulting from low-level acceleration—a case series of roller coaster injuries (44). Major spinal injuries occurred at a rate of 13 per 100,000 exposures despite the calculated generated forces of the roller coaster being similar in level and duration to those generated by a 3- to 4-mile per hour rear-impact collision.

From this review of the literature, it appears that McNab’s observations are accurate (33,35,45,46). I counsel patients that about 60% of patients have complete or nearly complete resolution of symptoms, most within the first few months, and that roughly 40% have persistent symptoms. Of an original injury group, about 10% to 20% have symptoms of sufficient nature to limit markedly their occupational or recreational activities. Instead of using the Quebec Task Force wording that patients “almost always” get better, and “rarely have permanent harm,” I prefer counseling patients that “usually” or “most often,” their symptoms will resolve, and that in only “a smaller percentage” of cases will long-term significant symptoms or permanent damage become evident.

OFFICE EVALUATION

The key to any care is the initial establishment of a solid patient-physician relationship. This is accomplished with a careful attainment of the patient’s history, a review of the patient’s self-intake documentation (e.g., pain diagram, self-reported functional scales, SF36), and performance of a thorough physical examination. A patient with discogenic neck pain often has a history of trauma, usually complains of pain with forward flexion, usually has increasing symptoms with driving (whole-body vibration), and usually experiences some relief with postural changes. The social history is often of particular importance so that specific documentation of compensation and litigation issues is undertaken. Indicators of depression on intake evaluation forms or noted on examination are documented. The neurologic examination, which may appear less important in this group with dominant axial neck pain, should nonetheless be detailed because it is still imperative to correlate lesser radicular symptoms and signs clinically, with the available anatomic imaging studies.

Although the classic incongruency signs were validated for low back pain, I use a similar approach in evaluating patients with a chief complaint of neck pain (47). If light touching of the skin causes violent complaints of pain, if whole-arm numbness or multiroot breakaway weakness is noted, or if the patient exhibits pain behavior consistent with overreaction, I then formalize the psychosocial evaluation. This is done with an Minnesota Multiphasic Personality Inventory (MMPI) study or referral for a formal psychological assessment. For example, a patient with overreacting chronic pain behavior of grimacing and “owching,” with breakaway weakness and complaints of pain with light palpation, and with documented disillusionment with the medical profession or depressive tendencies on our intake forms would not be initially considered a candidate for surgical workup and would be encouraged to participate in a multidisciplinary pain program.

In patients who have failed an active nonoperative program, who generally have symptoms of at least 12 to
18 months’ duration, and who have no apparent psychosocial contraindication, I then evaluate the imaging studies for potential objectification of a surgical level. This includes plain radiographs with flexion/extension views and typically magnetic resonance imaging (MRI). Specific neurologic compression or lack thereof, morphologic status of the intervertebral disk spaces, and presence or absence of mechanical instability are recorded. If the leading differential diagnosis is established as discogenic neck pain, I then recommend cervical diskography. This is done after a careful explanation to the patients that this is a quality-of-life issue. Patients must assess whether their symptoms affect their daily activity to such a degree that an approximate 70% to 80% chance of substantial improvement of pain (which is what we estimate based on our experience and the literature) justifies the risk of surgery. In general, younger patients are considered for one- or two-level procedures, whereas multilevel procedures are considered if the patient’s physiologic status appears to predict a decreased physical demand on the cervical spine.

NONOPERATIVE MANAGEMENT

Although nonoperative management is also detailed in another chapter of this text, a brief comment regarding the philosophy of our center is in order. Our focus is on active patient participation in aerobic conditioning, active rangeof-motion exercises, cervical strengthening, and upper and lower extremity strengthening. We recommend education regarding body posture and mechanics. For the patient with chronic pain, I find little or no role for passive physical therapy or chiropractic treatments alone (48, 49 and 50). I do recommend medications if they improve the patient’s symptoms. These generally include a nonsteroidal anti-inflammatory drug as well as acetaminophen and may include a mild narcotic agent. If work site issues are a concern, a therapist or other professional may be suggested to visit the work site and make specific ergonomic recommendations in order to maximize the patient’s function. I generally do not recommend placing the patient off duty, but rather on restricted duty, allowing the patient and the employer to work out the details. This type of approach, even in the chronic phase, can help certain patients avoid a surgical workup.

DISKOGRAPHY

It appears that use of the diagnostic tool of diskography still emotes controversy. What it really comes down to is how diskography is used in the decision-making process to recommend or not recommend surgery, thus affecting the clinical outcome that is perceived by the patient. If one is to undertake the surgical care of a patient with discogenic neck pain, then it is imperative to include diskography to maximize the surgical success rate (51, 52 and 53). Zeidman and Thompson (54) eloquently reviewed the subject in the third edition of The Cervical Spine, but an update is pertinent.

Most of what we call “degeneration” of the cervical spine comes from our interpretation of anatomic imaging studies. When there are discrete signs and symptoms of cervical radiculopathy, anatomic imaging that confirms our clinical diagnosis of a specific nerve root compressive lesion may suffice as the surgical roadmap for operative intervention. However, using anatomic imaging alone as a blueprint for a cervical reconstructive procedure in an individual with axial mechanical pain will likely lead to a large number of clinical failures owing to the number of asymptomatic individuals with abnormalities documented on other imaging studies (55, 56, 57, 58, 59, 60 and 61).

Only gold members can continue reading. Log In or Register to continue