recent years have seen growing numbers of cervical disc replacements and fusions due to improved surgical techniques.1,2,3 diagnostics and differential diagnostics have been highly standardized;4 however , recurrent cervical symptoms frequently occur.5 possible vertebrogenic causes lie within the treated or adjacent segments ( table 1).6 . primarily , local diagnostics of these causes are required ( table 2 ) ; yet , no algorithm for the diagnostic assessment of recurrent cervical symptoms has been established to date.7 this bears the risk that non - vertebrogenic causes of cervical symptoms are diagnosed at a late stage .
a 53-year - old nonsmoking man presented to our outpatient clinic with a new episode of cervicobrachialgia after a 2-year symptom - free interval .
two years ago , because of bilateral foraminal stenosis at c5/6 and c6/7 with increasing cervicobrachialgia , decompression and fusion at the severest level c5/6 ( pina titan cage 8 mm 14    16 mm ) and disc replacement at c6/7 ( prodisc - c xl 8 mm ) had been performed due to different degenerative changes . in the preoperative routine check - up
routine cervical x - ray had shown a stable fusion and a beginning kyphosis of the disc prosthesis ( fig .
two years after surgery the patient reported recurrent cervicobrachialgia ; however , cervical magnetic resonance imaging ( mri ) including stir sequences showed no pathological findings except for incipient foraminal stenosis at levels c3/4 and c4/5 due to uncovertebral arthrosis ( fig .
therefore , no further imaging or invasive investigations such as computed tomography ( ct)-myelography were indicated .   ( a ) postoperative cervical x - ray , lateral view .
( b ) postoperative cervical x - ray , anteroposterior view .   a 2-year postoperative cervical mri , t2-weighted sagittal view .
during the next 6 months his symptoms got worse with increasing numbness and weakness of the right arm .
repeated cervical mri revealed bone metastases of the fourth and fifth vertebrae with intraspinal tumor growth ( fig .
3 ) . thoracic x - ray and ct demonstrated an extensive small cell bronchial carcinoma ( figs .
4,5 ) . beginning paraparesis required immediate treatment comprising debulking , radiotherapy as well as etoposide and cisplatin chemotherapy .
subsequent to deterioration of his general state of health , the patient died 2 weeks after the cancer diagnosis of cardiopulmonary decompensation .  
( b ) a 2.5-year postoperative cervical mri , t1-weighted axial view .   a 2.5-year postoperative thoracic x - ray , anteroposterior view .   a 2.5-year postoperative thoracic ct , axial view .
good - to - excellent clinical results with a low complication rate are reported for ventral cervical fusion and disc replacement.8,9,10 this applies likewise to disc replacement in combination with fusion.11,12 yet , postoperative cervicobrachialgia is not uncommon.5,13,14 especially after a symptom - free interval of 2 years recurrent cervical symptoms are often believed to result from vertebrogenic causes .
metal artifacts complicate the evaluation of mri and ct scans.15,16,17 the absence of neurological deficits demands a nonsurgical treatment leading to a successful outcome in most patients.6 however , recurrent cervicobrachialgia without pathological cervical imaging requires interdisciplinary diagnostics . to our knowledge , there is only one report of a similar case in the literature .
pillai et al 18 presented the case of a patient developing metastases at the site of the arthroplasty 1 year after fusion at c3/4 to caution spine surgeons about the possibility that metastases might occur at the site of a cervical fusion and that a metastatic tumor should be accounted for in the differential diagnosis of recurrent cervicobrachialgia .
basic diagnostic tests , such as thoracic x - ray , erythrocyte sedimentation rate , c - reactive protein , and electrocardiogram may assist to exclude severe nonvertebrogenic pathologies .
this case illustrates the need for interdisciplinary diagnostics in recurrent cervicobrachialgia without pathological cervical imaging .
there are three important learning points here :  not everything that looks like a horse is a zebra .
 however , just because disc degeneration is so very common should not mean that we operate on all patients with cervical imaging abnormalities . the principle of evaluating a patient clinically and then
connecting clinical findings with insights gained by imaging remains the time - honored principle of spinal management for a good reason . for patients with neck / arm symptoms a differential diagnosis of other pathoentities , such as primary shoulder problems , compressive neuropathies , brachial plexus lesions , radiculitis or parsonage - turner syndrome and in rare cases malignancy ( pancoast tumor ! ) or infection are important considerations to keep in mind .
the use of electrodiagnostic tests , such as electromyography , is frequently shunned in this era of painless advanced imaging but is essential to differentiate a radiculopathy from a brachial neuritis and a compressive neuropathy .
symptom recurrence after spine surgery : melloh and barz correctly point out that symptom recurrence after neural decompression surgery is not uncommon and is multifactorial . a structured approach toward symptom recurrence is indeed helpful .
the ebsj editors recommend the methodical five - step approach suggested by the late henry bohlman : was the index surgery done for the right reason in the right patient at the right time ? was the surgery done well ?
has everything healed well ? has something new occurred , such as recurrent stenosis , breakdown above or below , infection , neoplasia , neurodegenerative disorder , metabolic disease , and so on ?
the commentary by john g devine might help settle some of the rampant misperceptions , especially regarding use of mri following arthroplasty and invite a more systematic approach to be formulated .
department of orthopaedic surgery eisenhower army medical center melloh and barz describe an interesting case of recurrent cervicobrachialgia after a 2-year symptom - free period .
the patient had undergone a two - level anterior cervical discectomy with a fusion at the c5/6 level and an arthroplasty at the c6/7 level .
the initial work - up included cervical x - rays and magnetic resonance imaging ( mri ) including stir sequences that revealed no obvious pathological findings .
as his symptoms progressed over the next 6 months , a repeated cervical mri was obtained revealing metastatic lesions of the fourth and fifth cervical vertebrae with extension of the tumor into the canal .
eventual diagnosis was made after thoracic computed tomography ( ct ) revealed the origin of the metastasis to be small cell bronchial carcinoma .
the authors point out that there is only one other reported case in the literature.1 however , this is not an uncommon clinical scenario .
in addition to a medical history and physical examination , first - line imaging should include x - ray evaluation and mri .
titanium devices allow for satisfactory imaging of the adjacent and index levels , but non - titanium devices ( cobalt - chrome - molybdenum alloys ) create significant image distortion , preventing accurate imaging at the index and adjacent levels.2 more recently , it has been demonstrated that magnet strength affects the artifact from cobalt - chrome alloys . using a lower strength magnet ,
such as the 0.2 tesla magnet found in many of the open scanners , the reduction in artifact allows for adjacent segment imaging without a significant reduction in quality.3 however , the index levels are still significantly distorted . in cases when symptoms persist without an obvious explanation using mri - myelography followed by ct - myelogram is the imaging modality of choice . the image distortion can be minimized , while allowing better visualization of the vertebral morphology , and earlier detection of trabecular destruction in the case of metastasis . additionally , the presence of neural compression can be appreciated centrally and in the proximal nerve roots at every level , including the index level after arthroplasty .
last , other imaging modalities can be used to detect the presence of occult metastasis in the setting of disc arthroplasty when the index of suspicion is high on the differential , or if there is already a diagnosis of malignancy and staging is required .
technetium-99 m bone scan is useful to identify areas of amplified metabolic activity and has a high sensitivity for detecting lesions .
positron emission tomography uses fluorodeoxyglucose to define sites of increased metabolic activity and is more sensitive and specific in detecting bone metastasis . as
melloh and barz make clear , in cases when no obvious pathology is identified in the initial mri in patients presenting with recurrent symptoms after disc arthroplasty , interdisciplinary diagnostics may be required .
in addition to basic diagnostic tests , such as erythrocyte sedimentation rate and c - reactive protein , x - rays and electrocardiogram , i would also recommend ct - myelogram in the setting of a preexisting disc arthroplasty .
 recurrent cervical symptoms frequently occur after cervical disc replacement and fusion . to date , no algorithm for the diagnostic assessment of these symptoms has been established . 
 we present a case report and review of the literature to illustrate the need for interdisciplinary diagnostics in recurrent cervicobrachialgia without pathological cervical imaging . 
 the hospital chart , medical history , physical examination , and imaging of a single patient were reviewed . a 53-year - old man with preexisting cervical disc replacement and fusion presented with a new episode of cervicobrachialgia after a 2-year symptom - free interval . 
 cervical magnetic resonance imaging ( mri ) showed no pathological findings . 
 six months later the patient reported increasing symptoms including numbness and weakness of the right arm . 
 repeated cervical mri and thoracic computed tomography revealed cervical metastases with intraspinal tumor growth and an underlying extensive small cell bronchial carcinoma . in recurrent cervicobrachialgia , without pathological cervical imaging , interdisciplinary diagnostics are needed . 
 basic diagnostic tests may assist to exclude severe non - vertebrogenic pathologies . 
Introduction
Report of a Case
Discussion
Conclusion
Editorial Perspective
Commentary