Surgical Management of Axial Pain

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CHAPTER 39 Surgical Management of Axial Pain

Patients who present for evaluation rarely state, “I have C7 radiculopathy from a soft herniated intervertebral disc on right hand side at C6-7.” Rather, they complain of pain, weakness, numbness, or some combination of these. Most often, their actual chief complaint is that of neck pain. On careful assessment, the physician may determine that the individual has radiculopathy—generation of symptoms from pathology associated with a specific cervical nerve root, which manifests in the form of pain perceived in the neck, upper trapezium, parascapular region, or distally into the arm.

The assessment consists of obtaining a through history and physical examination with judicious use of imaging studies or laboratory values or both, which allows a specific diagnosis to be rendered. With that diagnosis, the physician counsels the patient about the operative and nonoperative options that exist for that specific patient, with his or her uniqueness, as related to the given diagnosis. This chapter is designed to enable the reader to approach the patient with a chief complaint of “neck pain” with a rational surgical decision-making process.

Epidemiology and Natural History

Having an appreciation of the factors that affect the health of the population is important in understanding the individual who seeks treatment. A study of adolescents concerning the prevalence of musculoskeletal pain in Finland revealed only approximately 25% of 18-year-old girls and about 50% of boys with no report of neck or arm pain in the last 6 months.¹ Of these self-reports to questions about musculoskeletal pain, only a small single-digit percentage sought medical consultation. The author’s of the Finnish study note that this prevalence is high, but that the relevance of such reported pain is questionable without knowing the magnitude of the pain-related disability.

It is known from population-based sectional survey studies that numerous individuals complain of acute or chronic neck pain.²^–⁴ The overall prevalence of “troubles or neck pain” was 34.4% in a Norwegian registry, with 13.8% of that group reporting chronic neck pain of greater than 6 months’ duration.² Similar numbers were reported by Makela and colleagues⁴ in a study of chronic neck pain in Finland. In an article on the Saskatchewan population published in 2000, Cotes and colleagues³ found that 54% of 1131 respondents had experienced neck pain in the previous 6 months. Of that group, 5% reported that they were “highly disabled” because of neck pain. A comprehensive review by Manchikanti and colleagues⁵ suggested that the prevalence of people with high pain intensity with disability owing to neck pain is 15%, with 25% to 60% having chronic symptoms 1 year or longer after the initial episode. Complaints of neck pain in the population are common, if the question is asked, but only a small percentage are plagued enough to seek care; if they do seek care, a fair number of people have persistent pain that may lead to surgical consultation.

Why Understanding the Natural History of a Condition Is Crucial

The speed and intensity of assessment of a patient vary depending on whether the condition is benign and self-limiting or one that without urgent intervention would be fatal or lead to serious disability. A patient who presents with an acute progressive loss of neurologic function owing to an expanding epidural abscess, mandates emergent treatment, most often surgical, because of the dismal prognosis if left untreated. Alternatively, a healthy, young individual with neck pain, with no fever or chills, who is normal neurologically, often improves spontaneously, and in such a case, patient reassurance is advised. It is important that the initial evaluation screen out patients with the potential for an ominous diagnosis, such as tumor, infection, significant progressive myelopathy, or an unstable segment owing to inflammatory arthropathy.

In patients with apparent mechanical axial pain resulting from a degenerative condition, observation with nonoperative recommendations would be appropriate for most patients. When reviewing natural history studies, there is the inherent selection bias of individuals who sought care because of the severity of their symptoms. Many individuals who report pain on population surveys of prevalence of symptoms would not seek out care. In a population questionnaire study, Badcock and colleagues ⁶ found that 11.7% of questionnaire responders had neck pain and that 21% sought general practice consultation; 77% of responders seeking consultation had persistent symptoms, which was a greater percentage of persistent disability than among responders who did not seek out consultation.

Gore and colleagues ⁷ published a classic series on the long-term follow-up of patients who present with neck pain. With a minimum 10-year follow-up, clinical and radiographic data were reported on 205 patients with a chief complaint of neck pain. Of that group, “79% had a decrease in pain, and 43% were pain free; however, 32% had moderate to severe pain.”⁷ The investigators noted that a specific injury and severity of the initial pain were suggestive of having an unsatisfactory long-term outcome.

In an earlier edition of this text, Rothman ⁸ stated that “it does not appear that cervical disc degeneration is a brief, self limiting disorder, but rather a chronic disease, productive of significant pain and incapacity over an extended period of time.” DePalma and Subin⁹ reported in 1965 that among patients treated nonoperatively for “cervical syndrome,” only 45% of those presenting for treatment with a chief complaint of neck pain or neck with arm pain had a long-term satisfactory outcome. In a series of the results of anterior cervical discectomy and fusion (ACDF) for cervical spondylosis, DePalma and colleagues¹⁰ reported that 21% had complete relief at 3 months with nonoperative care, whereas 22% had no relief. In a 5-year follow-up study of patients presenting with significant complaints of pain secondary to cervical disc degeneration, Rothman and Rashbaum¹¹ noted that 23% remained partially or totally disabled.

When one looks at more recent publications, these classic studies are mirrored. Walker and colleagues ¹² performed a randomized clinical trial of manual physical therapy and exercise compared with minimal intervention in 94 patients presenting with neck pain, with or without arm pain. At 1-year follow-up, 62% of patients perceived success with treatment, which means that 38% had persistent symptoms, and only 32% in the minimum intervention group perceived treatment success, which means that 68% had persistent complaints. A classic study of the natural history of cervical spondylosis by Lees and Turner¹³ and a review in the 1980s showed that patients presenting with cervical radiculopathy do not typically progress to myelopathy. Two thirds of patients treated with nonoperative care had consistent complaints of pain, although not severe in all.

Studies on epidemiology and natural history would suggest that in patients whose symptoms are severe enough to present for evaluation and care, only a small percentage, perhaps 20% to 30%, have symptoms of sufficient magnitude to warrant consideration of a surgical diagnostic workup. Although a small percentage, it nonetheless represents a significant number of patients who deserve a rational surgical decision-making approach from the medical team, as opposed to nihilism.

Etiology

Understanding the cause or reason for an individual patient’s symptoms is crucial in allowing the physician to make treatment recommendations. Although the most common reason—and the focus of this chapter—that a surgeon sees a patient in consultation for neck pain is a degenerative condition, one must maintain an initial broad differential diagnosis. A patient with a metastatic pathologic fracture of C6 may not know he or she has a tumor as the etiology of his or her “neck pain.” It is up to the physician to determine this and then direct the care that leads to a medical evaluation; imaging and laboratory assessment, likely including biopsy; and potential for surgical management with decompression and reconstruction. The chief complaint of neck pain was the entry into the rational surgical decision-making approach.

If the broad differential diagnosis leads to infection as the etiology, be it discitis or osteomyelitis, with potentially an epidural abscess, the patient requires a more through diagnostic workup, which would lead to surgical intervention if medical treatment has failed, if a tissue diagnosis needs to be established, or if there is neurologic deterioration. Patients with systemic arthritides may be seen. Typically, this is a patient with rheumatoid arthritis whose neck pain is out of context to their other joint pains and is not responding to current immunologically mediated treatment. One may see “staircase” subaxial multilevel degenerative spondylolisthesis or craniocervical instability that leads to a recommendation for fusion surgery. Patients presenting with neck pain may not know that they have a seropositive arthritis, and the surgical evaluation could best help redirect away from surgery to enhanced rheumatologic care.

Trauma is always part of a broad differential diagnosis, and in cases of obvious fracture-dislocations, surgical management often is the preferred treatment. In certain conditions such as ankylosing spondylitis, even trivial trauma leading to a complaint of neck pain needs careful scrutiny because the patient may have a serious fracture pattern that can lead to progressive deformity or neurologic loss of function if left untreated.

In relation to trauma, numerous patients are seen who have a rear-end mechanism motor vehicle accident as the etiology for their complaint of neck pain—that is, a “whiplash” injury. The Quebec Task Force on Whiplash-Associated Disorders produced a monograph concluding that patients should be reassured that whiplash-associated disorder is “almost always” self-limited and that it “rarely results in permanent harm.”¹⁴ In rebuttal, Freeman and colleagues¹⁵ performed a methodologic critique of the literature and stated, “there is no epidemiologic or scientific basis in the literature for the following statement: whiplash injuries do not lead to chronic pain, rear end 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.”

Although currently there is an emphasis on performing better designed studies of early nonoperative management of whiplash-associated injuries, a rich history of observational studies does not exist.¹⁶ McNab¹⁷ reported on 266 patients, out of an original group of 575 patients with soft tissue neck injuries, who were 2 years after settlement of court issues, so as to minimize the bias of legal secondary gain. Of these 266 patients, 145 were available for review, with 121 reporting persistent pain; at minimum, 45% (121 of 266) had symptoms 2 years after court settlement per their injury.^17,¹⁸ In a similar type of study, Hohl¹⁹ noted that of 146 patients who had no pr-existing degenerative condition, 45% had persistent pain 5 years after injury, and in a continuing series from the United Kingdom following patients with whiplash injuries, 66% were noted to have complaints of pain at 2 years after injury, with 10-year follow-up revealing reports of “intrusive pain” and 28% “severe” pain in 12%.²⁰^–²² In a prospective Scandinavian series of 93 patients, Hildingsson and Toolanen²³ noted complete recovery in 42%, mild discomfort in 14%, and significant residual complaints in 44%. Likewise, Jonsson and colleagues²⁴ reported that 28% (14 of 50) of patients with whiplash distortions had persistent symptoms. Although changing from a tort to no-fault system, to eliminate compensation for pain and suffering, decreases the percentages with whiplash injury from a motor vehicle accident, Cassidy and colleagues²⁵ wrote that the prognosis for individuals with whiplash injury is affected by “… Intrinsic factors such as age, sex, and initial intensity of the pain.” In a series on early aggressive care for patients with whiplash injury, Cote and colleagues²⁶ noted that their “results add to the body of evidence suggesting that early aggressive treatment of whiplash injuries does not promote faster recovery.”

When seeing a patient with whiplash-associated injuries, it would seem that clinicians may counsel them that “usually” or “more often” their pain will subside as they heal themselves and that only a “low percentage” will have long-term permanent damage. This counseling is in contrast, however, to the wording that the patient “almost always” gets better and “rarely has permanent harm” as suggested by the Quebec Task Force.¹⁴ In perhaps 10% to 20% of an original whiplash injury population, a surgeon would benefit a patient by proceeding with a diagnostic evaluation to objectify specific anatomic pathologies that may be remedied with open or minimally invasive surgical intervention.

Patient Evaluation

History

Evaluation of a patient with a chief complaint of neck pain is no different than evaluation for any other complaint of spinal pain. Obtaining a thoughtful history, performing an insightful physical examination, and carefully reviewing imaging studies yield a differential diagnosis and likely a favored specific diagnosis.

One needs to assess the onset (traumatic vs. nontraumatic, acute vs. insidious) and the location of the pain and whether it is local, referred (basioccipital, upper trapezial, or periscapular), or radicular into the arm. A specific assessment of the component that is related to neck pain versus arm pain is crucial (e.g., 80% neck pain and headaches vs. 20% arm pain). Neurologic symptoms of numbness, tingling, weakness, sphincter dysfunction, or ataxia are sought. The pattern of pain is important. Is the pain worse with flexion activities? Does it increase as the day goes on and respond to rest? This finding would suggest a discogenic source, which is a common presenting condition. Unilateral radiation to the upper trapezial and interscapular region that restricts turning the head to that side suggests a radicular component. A history of a known diagnosis of cancer or infection is noted, and constitutional symptoms of night pain, rest pain, fever, and weight loss are reviewed. The social history documents the presence or absence of litigation, workers’ compensation activity, and use of tobacco. The family history may suggest a genetic predisposition. The patient’s self-reported documentation should be reviewed (e.g., pain diagrams, visual analog scale [VAS], self-reported functional scale, SF-36, patient expectations). The pain diagram can be very useful in the assessment of axial mechanical pain with the continuum of those suggesting an anatomic source that makes one think more of a surgical option versus those suggesting a nonorganic source where one thinks less of invasive testing to determine a surgical option (Fig. 39–1A).

FIGURE 39–1 Contrast these two scenarios. A, Pain diagram showing anatomic pathology with realistic expectations of what surgery can do. B, Pain diagram linked with expectations that would, by themselves, not suggest pursuit of a surgical option.

The psychosocial evaluation is critical. True malingerers are rare but do exist.²⁷ Symptom amplification, drug-seeking behavior, work-related litigation, motor vehicle accident litigation, clinical depression, and frank psychiatric dysfunction all can have an impact on the patient’s self-perceived outcome as it relates to the success of elective surgical intervention for axial neck pain. A patient with a nonorganic diagram (Fig. 39–1B) who presents with a history of daily intake of high doses of narcotics, with active litigation, and who smokes two packs of cigarettes per day would suggest delay in surgical management. In a published series in 2002 on axial neck pain, the author and colleagues were unable to correlate a negative outcome with the presence or absence of litigation or cigarette smoking.²⁸ A series from Cleveland documented that of patients who took daily narcotics for greater than 6 months, 51% (24 of 47) reported good to excellent outcome, and 32% (15 of 47) had a poor result.²⁹ These findings contrast with patients without chronic narcotic use having 86% (38 of 44) good to excellent outcomes and no patients with a poor outcome.²⁹

Physical Examination

A thorough physical examination follows the history. The range of motion, or limitation of such, is recorded. Motor function, sensation, deep tendon reflexes, upper motor neuron signs (e.g., Hoffmann, Babinski, clonus), gait, and provocative or ameliorative maneuvers are evaluated. Although the neurologic examination may seem less important in patients with complaints of 90% neck pain and 10% arm pain, it is still vital to rule out myelopathy or significant dysfunction, and it is useful for clinical correlation. In a patient who presents with complaints of 90% neck pain and 10% arm pain into the right thumb and index finger and who has decreased sensation in a C6 distribution, with a diminished brachioradialis reflex and with decreasing symptoms with shoulder abduction, a C5-6 disc herniation is suggested.

Radiographic Evaluation

The outpatient evaluation should be sequential. A history and physical examination are followed by plain radiographs before magnetic resonance imaging (MRI) or computed tomography (CT). The author routinely obtains an anteroposterior, lateral, and flexion-extension lateral radiographic series. Open-mouth or oblique views do not need to be routinely obtained. These radiographs are ordered for destructive processes that indicate tumor or infection (and the history of axial neck pain did not suggest such) or for the presence of foraminal stenosis, for which one would typically obtain advanced imaging. The presence of spondylosis, as evidenced by loss of disc height, subchondral sclerosis, cyst formation, or osteophyte formation, and the presence of listhesis with any dynamic component to suggest mechanical instability are documented. Using these factors, the author and colleagues have reported on a quantitive radiographic scoring system, which yields a cervical degenerative index.^30,³¹ This objective assessment may be useful to follow patients regarding the progression of disease or patients who have had surgery regarding the development of adjacent segment degeneration. The index is an expansion of Gore’s assessment, and a higher score indicates more radiographic pathology at more levels. In a young patient with multilevel spondylosis, one would tend to encourage nonoperative treatment. The presence of spondylosis on radiographs is nonspecific and does exist in asymptomatic individuals, but the review of plain radiographs is still quite useful.^32,³³

Advanced Imaging

In a patient who has dominant axial mechanical neck pain, who has failed 12 months of nonoperative care, including an active rehabilitative component, in whom a psychosocial contraindication does not exist, and who perceives his or her pain to be so severe to consider surgical options, the next step is MRI. If MRI is contraindicated (e.g., pacemaker or metal fragment in the eye), a CT myelogram is done. The scan is reviewed for tumor, infection, or neurologic compression, but in this subgroup of axial pain, a special note is made of disc morphology, annular tears, small central herniations, listhesis with facet arthrosis, and the number of levels of involvement. In a patient who has a clinical correlation of C6 pattern, such as the previously mentioned patient with 90% neck pain and 10% arm pain, who has a central to right small C5-6 herniated nucleus pulposus with pristine-appearing C4-5 and C6-7 levels, no additional testing may be necessary. A C5-6 ACDF may be an option, but in this group of patients with axial pain, this type of clear-cut scenario is uncommon, and additional testing is more often advised. Also, numerous asymptomatic individuals have degenerative change on their studies, and the presence of these changes increases with age.³⁴^–³⁷

The debate on the rational basis to use discography continues.^38,³⁹ Nordin and colleagues,³⁸ citing a critical review of the literature, stated that “no evidence supports using provocative discography, anesthetic facet, or medial branch blocks in evaluating neck pain.” Manchikanti and colleagues³⁹ reported on a comprehensive search of the literature, using a modified Agency for Health Care Research and Quality (AHRQ) level of evidence evaluation, and documented that “cervical discography plays a significant role in selecting surgical candidates in improving outcomes, despite concerns regarding the false positive rate, lack of standardization, and assorted potential confounding factors.” Because of this discrepancy, perhaps related to the bias of the groups, an expanded review of discography is planned. In the author’s experience, discography is a useful clinical tool.

Advanced Invasive Diagnostics

Discography as a diagnostic tool is controversial. If one wishes to consider surgical options in patients with axial neck pain, of whom many have a discogenic source, the use of discography should be considered to maximize the surgical success rate.^28,^35,⁴⁰^–⁴⁵ This topic is discussed later in the section on surgical outcomes for axial neck pain.

To provide a surgical solution, objectification is the crucial factor. Because of the numerous asymptomatic individuals with positive MRI studies, procedures based on MRI alone for level selection in patients with dominant axial pain would have to have a very strong clinical correlation, such as a component of radiculopathy that fits with a specific herniated nucleus pulposus. Schellhas and colleagues ³⁵ published an article on the prospective correlation of discography and MRI in asymptomatic subjects and subjects with neck pain. These investigators concluded that MRI did not reliably identify the source of discogenic pain because annular tears often escape detection. It was not surprising that degenerative anatomic findings existed in the asymptomatic group. In only 3 of the 40 discs studied in asymptomatic individuals was there an elicited pain response, however, suggesting a favorable specificity and positive predictive value.³⁵

The use of cervical discography is common practice at the author’s center. It is ordered at multiple levels and is similar in nature to the practices of other authors.^37,^40,⁴¹ The key is to have a significant (>6 of 10) concordant reproduction of the patient’s presenting axial pain at the affected disc level with little or no pain at the adjacent control level. This concordant pain is the pain that the patient desires to be alleviated with surgical intervention.

What is difficult to publish a series on is how the discogram leads away from a surgical option. When there is no validating level, when every disc hurts, surgery is dissuaded. This is particularly the case in a young patient who has a frank herniated nucleus pulposus (approximately 20% of the asymptomatic population) who complains mainly of neck pain, without a strong clinical correlation, and who has multiple positive discograms. If one based selection of a fusion level on MRI alone in that scenario, a high percentage of clinical failures would likely follow.

Regarding the complications of discography, the published rates of discitis are very low (≤1%).^35,^40,⁴⁶ This low rate encompasses the technical skill of the discographer, size of the needle, and use of antibiotics.

Selective nerve root blocks are mentioned because there is overlap in patients presenting with “axial pain.” It may be that the patient has more unilateral pain in the neck coming into the upper trapezial region or the periscapular region but not so much into the arm. Findings appear normal on neurologic examination, but the patient may have increasing pain with Spurling maneuver. MRI reveals ipsilateral foraminal stenosis. In this patient, a selective nerve block can be very useful from a diagnostic and a potentially therapeutic perspective. If with a small volume of lidocaine placed at the nerve root in question the patient reports significant relief of clinical symptoms, consideration of decompression of that nerve root is rationally based if the symptoms return. In this case, the axial pain is secondary to a radicular component perceived along the course of the primary posterior ramus, not the ventral ramus. A posterior laminoforaminotomy may suffice in this case, although an ACDF might also remedy the symptoms.

Comments on facet joint blocks or medial facet rami blocks are limited here. The author knows of no peer review literature that bases a decision to proceed with fusion surgery dictated by this testing. Most of the literature on these blocks has been with the diagnostic value of an anatomic source, and specifically in patients with whiplash-associated disorder.⁴⁷^–⁴⁹ Although some publications have suggested relief of pain associated with whiplash and in patients with chronic axial neck pain (with or without traumatic etiology), the author’s experience has not favorably reproduced those outcomes.

Although intuitively if a patient reports excellent relief of pain with blocks to specific joints, it would seem that surgical arthrodesis of the joints may be beneficial, this has not been shown, and concern about leakage of the anesthetic onto the nerve root or spinal cord may discourage use of this technique. Using facet blocks for surgical decision making should be done in the context of a formal study.

Surgical Outcomes for Axial Neck Pain

The pragmatic question to the surgeon is this: “Does your selection process, based on whatever criterion you choose, yield a reproducible, discernible impact on the patient’s chief complaint, which at 2- to 5-year follow-up would lead that patient to repeat the procedure and self-rate that surgical intervention as successful?” The currently discussed diagnostic workup approach has led the author to reply to that question with an affirmative response (Fig. 39–2).

FIGURE 39–2 A-C, This patient had a chief complaint of 80% neck pain and 20% arm pain, with left-sided pain greater than right-sided pain. MRI shows herniated nucleus pulposus at C6-7 level, but it is left-sided, and degenerative change with small disc protrusions proximally. A C7 selective block gave excellent temporary relief of symptoms suggesting that C6-7 pathology was the prime pain generator. Anterior cervical discectomy and fusion at C6-7 was done, and at 1-year follow-up the patient’s lateral radiograph shows solid fusion with excellent resolution of neck pain.

Although prospective randomized trials are considered of higher value, much can also be gleaned from the cohort observational–based surgical literature.^28,^37,^{41–45,50–55} In a clever tongue-in-cheek meta-analysis of the protective effect to the gravitational force affected by a parachute, Smith and Pell⁵⁶ found no published prospective randomized trials of such! No one doubts the value of a parachute, or for that matter of a hip arthroplasty, yet one does discount surgical treatment of axial pain.

In a series of 112 consecutive patients, the author and his colleagues were able to obtain 87 responses to an extensive follow-up questionnaire at an average of 4.4 years. In this group, 20 patients had multilevel procedures, whereas 67 had single-level or two-level ACDF. The author and colleagues reported by fusion level and etiology (traumatic, workers’ compensation, or degenerative) but found no statistical difference among the groups. Pain improvement was noted in 93% (81 of 87), with the average VAS decreasing from 8.4 before surgery to 3.8 at long-term follow-up. On a 6-point Likert scale of excellent, very good, good, fair, poor, or terrible, 82% (71 of 87) self-rated their outcome to be good, very good, or excellent. Two modified cervical functional assessments were used, with the patient reporting an average 50% improvement on both. A negative correlation with the presence or absence of compensation or litigation or with tobacco use was not documented. The author and colleagues estimated that the 112 patients represented 4% of the surgical practice of the attending physicians involved during the acquisition phase (Fig. 39–3).

FIGURE 39–3 A-E, This 58-year-old woman has a diagnosis of positive rheumatoid arthritis. She presented previously in 2001 and had a two-level anterior cervical fusion. She now has significant neck pain as her chief complaint with base of the skull headaches and mild myelopathy symptoms. Her neck pain is greater on left side than right side. Images show advanced spondylosis at C5-6 and C6-7 with degenerative spondylolisthesis of C7 on T1. She has erosive arthritic change at C1-2 with early pannus formation ventral to brainstem, with increased cervical medullary angle. The patient had occipital-to-T1 fusion, with excellent resolution of her symptoms and ability to return to light duty full-time employment.

In a 2004 publication on the value of MRI and discography in the patient selection process for ACDF, Zheng and colleagues ³⁷ reported on 55 patients with 76% good or excellent results, 18% fair results, and 6% poor results. In 1999, Palit and colleagues⁴¹ reported on 38 patients for “dominant neck pain, with no symptoms or signs of radiculopathy or myelopathy.” They used the “patient satisfaction index,” with 79% (30 of 38) indicating satisfaction with their surgical outcome and 21% (8 of 38) indicating they were not satisfied. Table 39–1 outlines series with similar diagnostic criteria after ACDF for neck pain (some in patients with arm pain) that show consistent results. The results in these series suggest that ACDF is a reasonable surgical option for neck pain in well-selected patients.

TABLE 39–1 Results of Anterior Cervical Discectomy and Fusion for Axial Pain

Study	No. Patients	Reported Outcome
Zheng et al³⁷	55	76% good or excellent, 18% fair, 6% poor
Garvey et al²⁸	87	82% good or excellent, 16% fair, 2% poor
Ratliff and Voorhies⁵²	20	85% satisfaction
Motimaya et al⁵¹	14	78.6% satisfaction
Palit et al⁴¹	38	79% satisfactory, 21% not satisfactory
Whitecloud⁵⁴	34	70% good or excellent, 12% fair, 18% poor
Roth⁴⁴	71	93% good or excellent, 1% fair, 6% poor
White et al⁵³	28	62% good or excellent, 23% fair, 23% poor
Riley et al⁴²	93	72% good or excellent, 18% fair, 10% poor
Simmons et al⁴⁵	30 with neck pain; 51 with neck and arm pain	78% good or excellent, 15% fair, 7% poor
William et al⁵⁵	15	1 excellent, 3 good, 5 fair, 6 poor
Dohn⁵⁰	34	62% good or excellent, 24% fair, 15% poor
Robinson, et al²	56	73% good or excellent, 22% fair, 5% poor

Current readers must also appreciate the wealth of information available from the publications of the pioneers of ACDF surgery. In 1962, Robinson and colleagues ⁴³ reported on their continued ACDF experience. This series was of 56 patients with 80% (45 of 56) reporting neck pain, 45% (25 of 56) noting occipital pain, and 46% (26 of 56) having interscapular radiation. A traumatic etiology was noted in 68% (38 of 56), with 25 being indirect, such as a “rear-end automobile collision.” Discography was used in 84% (47 of 56) of patients. The investigators switched from preoperative use to intraoperative testing owing to the patients complaining of pain with the actual procedure. In this classic series, 73% (41 of 56) considered themselves to have good or excellent results, with 22% (12 of 56) fair and 5.5% (3 of 56) poor. Pseudarthrosis was noted in 16% (9 of 56); 4 of the 9 patients were symptomatic. The stated conclusion was “when other treatment seems impractical, anterior interbody fusion appears to be a good surgical treatment for degenerative joint and disc disease of the cervical spine.”

In 1969, Riley and colleagues ⁴² noted quite similar results in 93 consecutive cases. In a review paper, Riley⁵⁷ commented on psychosocial issues. He noted that “prolonged pain is associated with a definite emotional response which may be more disabling than the pain itself.” He noted a series of patients with chronic neck pain who also as a group were irritable and depressed, who did not generate warm patient-physician relationships, but who did respond to surgical treatment, with the disappearance of their emotional characteristics when they had successful relief of their pain.

Pseudarthrosis

Pseudarthrosis is a common diagnosis for patients presenting with a chief complaint of neck pain. Although an anatomic pseudarthrosis may exist, one must be certain that this is the source of the “neck pain.” Adjacent levels need to be assessed, and the original diagnosis that led to ACDF that resulted in pseudarthrosis should be reviewed. With that stated, the literature supports that conversion to a solid arthrodesis yields 70% to 80% good to excellent clinical outcomes.⁵⁸^–⁶⁰ The reports vary regarding repeat anterior procedures, posterior procedures, and combinations of both. The key is to have a specific objective diagnosis and then remedy that pathologic process.

Some patients present with new or continued complaints of neck pain after having had fusion surgery. Although the presence of an anatomic pseudarthrosis can be documented by radiographic or CT scan evaluation, one must assess the patient carefully to determine that this objective finding of pseudarthrosis is the specific etiology for the pain. The original diagnosis that led to ACDF, the timing of onset of neck pain (usually early but not immediate), and the health of the adjacent segment all must be considered. With that noted, the literature supports 70% to 80% good to excellent outcomes with conversion to a solid arthrodesis.⁵⁸^–⁶² Reports vary regarding anterior, posterior, or combined approaches, but Carreon and colleagues⁶² noted a greater effectiveness of the posterior approach.

Disc Arthroplasty

Cervical disc arthroplasty has been a very hot topic in recent years. Much has been published. U.S. Food and Drug Administration (FDA) investigational device exemption studies and others have allowed clinicians to garner much information about the patient’s perceived outcomes as related to neck and arm pain in both arthroplasty groups and their control groups.⁶³^–⁶⁷ When one looks at the detailed data of these studies, an interesting point is that with inclusion criteria specifically having the patient treated for radiculopathy or myelopathy, the studies generally all report VAS scores for neck pain and arm pain. Generally, the VAS preoperatively is roughly equal for the arm and neck pain components—that is, each is in an approximate 7 to 8 of 10 points range, and on average decreases to a 2 to 3 of 10 points range postoperatively. What this means is that to the patient, neck pain is significant, and for outcomes, predictably it is relieved, just as is the arm pain.

When one asks what makes a patient satisfied with the outcome of surgery, Skolasky and colleagues ⁶⁸ noted regarding fusions that “clinical improvement, especially in neck pain, after surgery is associated with improved patient satisfaction.” In the arthroplasty control group of ACDF, Anderson and colleagues⁶⁹ studied 26 potential variables, as related to overall clinical success, and found that workers’ compensation status and weak narcotic use were negative predictors, whereas higher preoperative NDI scores and normal sensory examinations were positive predictors.

What can be said at present from these studies is that decompression and disc arthroplasty as a procedure is at least as good as (if not better than) ACDF for cervical spondylosis with radiculopathy and that neck pain is an important subjective component of why the patient solicits surgical intervention. In the next 5 to 10 years, studies may be seen that expand the use of motion-sparing surgery to address patients with dominant axial pain, with the same caveat as for fusion surgery, that the levels to be surgically repaired must be thoroughly objectified.