Manipulative Therapy There is moderate evidence for the effectiveness of manipulative treatment Manipulative therapy remains a mainstay of conservative treatment for degenera- tive disorders of the cervical spine. Particularly, traction has been reported to result in short-term relief of radiculopathy [60, 61, 197]. Debate continues on the safety of manipulative therapy of the cervical spine. Based on a national survey of 19122 patients, minor side effects (headache, fainting/dizziness, numbness/tin- gling) were not uncommon up to 7 days after the intervention, with an incidence rate ranging from 4 to 15/1000. Serious adverse events (leading to in-hospital treatment or permanent disability) were very rare (1/10000). However, this does not rule out a deleterious course in individual patients ( Case Introduction ). Rubin- stein et al. [230] concluded that the benefits of chiropractic care for neck pain seem to outweigh the potential risks. There is moderate evidence that spinal manipula- tive therapy (SMT) and mobilization is superior to general practitioner manage- ment for short-term pain reduction of chronic neck pain.However,SMToffersat most similar pain relief to high-technology rehabilitative exercise in the short and long term. In a mix of acute and chronic neck pain, there is moderate evidence that mobilization is superior to physical therapy and family physician care [41]. There are only a few studies on acute neck pain and the evidence is currently inconclusive [41]. Physical Exercises Moderate evidence supports physiotherapy for chronic neck pain There is moderate evidence supporting the effectiveness of both long-term dynamicaswellasisometricresistanceexercisesoftheneckandshouldermus- culature for chronic or frequent neck disorders. No evidence supports the long- term effectiveness of postural and proprioceptive exercises or other very low intensity exercises [106, 296]. Multidisciplinary Rehabilitation Programs Incontrasttothelumbarspine,thereappearstobelittlescientificevidencesofar for the effectiveness on neck and shoulder pain of multidisciplinary rehabilita- tion programs compared with other rehabilitation methods [145]. However, this conclusion is due to the low quality of available clinical trials [145]. Massage No clinical practice recommendations can be made for the effectiveness of mas- sageforneckpain[115]. Spinal Injections Transforaminal injections can results in serious complications Anecdotally, transforaminal injections with epidural steroid application can result in instant pain relief in patients suffering from cervical radiculopathy [70, 163, 262], although injection of local anesthetic appears to have similar effects [8]. However, recent articles have prompted major concerns over the safety of transforminal steroid injections because of cases with subsequent deleterious spinal cord injuries [120, 181, 245]. For chronic neck pain, intramuscular injec- tion of lidocaine was superior to placebo or dry needling at short-term follow-up, but similar to ultrasound. There is limited evidence of effectiveness of epidural injection of methylprednisolone and lidocaine for chronic neck pain with radicu- lar symptoms [208]. Degenerative Disorders of the Cervical Spine Chapter 17 447 Radiofrequency Denervation The treatment effect of radiofrequency denervation is unproven Although some studies reported satisfactory results [170, 253], there is limited evidence that radiofrequency denervation offers short-term relief for chronic neck pain of zygapophysial joint origin and for chronic cervicobrachial pain [188]. Acupuncture Theevidenceforacupunctureisconsideredinconclusive and difficult to inter- pret [27]. Electrotherapy The systematic review by Kroeling et al. [158] could not make any definitive con- clusions about electrotherapy for neck pain. The present evidence on galvanic current (direct or pulsed), iontophoresis, electromuscle stimulation (EMS), transcutaneous electrical nerve stimulation (TENS), pulsed electromagnetic field (PEMF) and permanent magnets is either lacking, limited, or conflicting. Infrared Laser Therapy The review by Chow et al. [55] provided limited evidence from one randomized controlled trial (RCT) for the use of infrared laser for the treatment of acute neck pain and chronic neck pain from four RCTs. Operative Treatment General Principles Degenerative disorders of the cervical spine are a heterogeneous group of pathol- ogies with a wide spectrum of treatment modalities. For the vast majority of clin- ical entities, surgery is only indicated after an adequate trial of non-operative treatment has failed. As outlined in the preceding paragraph, the scientific evi- dence for the effectiveness of many conservative measures is very limited. Simi- larly, the evidence is limited for the surgical treatment options. While surgery for chronic neck pain is not broadly supported, it appears that patients with CSR and CSM benefit from surgery after non-operative care has failed [86, 297]. Indica- tions for surgery for CSR and CSM include ( Table 6): Table 6. Indications for surgery Cervical spondylotic radiculopathy Cervical spondylotic myelopathy progressive, functionally important motor deficit definitive evidence for nerve root compression concordant symptoms and signs of radiculopathy persistent pain despite non-surgical treatment for at least 6 –12 weeks progressive myelopathy despite non-operative care acute onset, deterioration or progression of neurological deficits definitive evidence of spinal cord compression with moderate- to-severe myelopathic symptoms progressive kyphosis with neurological deficits The goal of CSM treatment primarily is to arrest progression Surgery for cervical radiculopathy is generally recommended when all of the aforementioned criteria are present [45]. The primary goal of surgery in CSM is the prevention of further pr ogression of the neurological symptoms because improvement of established myelopathic changes is rare [164, 166]. One of the most important aspects in dealing with CSM is to inform the patients preopera- 448 Section Degenerative Disorders tively that the goal of surgery is primarily to arrest progression of the disease. Patients are frequently disappointed by the results of surgery when neurological recovery is lacking although the vast majority of patients do show improvements [76, 127, 225, 294]. It is therefore reasonable to extensively inform patients about the goals and realistic expectations of surgery. Surgical Techniques There is an ongoing debate on the approach to deal with disc herniation related radiculopathy, CSR or CSM, i.e.: anterior approach posterior approach The pathology should be treated where it is Each technique has its advantages and drawbacks. The controversy which of the two approaches is better cannot be generalized but must always be related to the target pathology. It is important to recognize whether the compressing structure is anterior or posterior to the neural structures. The pathology should be treated where it is. Thus, an anterior neural compression is better removed from anterior and a multisegmental posterior compression from a posterior approach. In cases with three or more level stenosis, a posterior approach is preferred unless there is no coexisting substantial anterior compression. Anterior Cervical Discectomy and Fusion Anterior cervical discectomy and fusion remains the gold standard for CSR In 1955, Robinson and Smith [229] reported on a technique for removal of cervi- cal disc and fusion with a horseshoe-shaped graft which later became the gold standard for the treatment of disc herniations and cervical spondylotic radiculo- pathy [260]. Cloward [62] developed a similar anterior approach, i.e. drilling a hole in the intervertebral disc space and adjacent vertebrae to insert a bone dowel. In contrast to the Robinson-Smith technique, Cloward removed the com- pressing structures at the level of the posterior longitudinal ligament. Robinson and Smith [229] did not decompress the neural structures, but believed that by immobilizing the segment osteophytes and herniated disc would be reabsorbed. In the following years many variations of this technique were developed [12, 35, 37, 77, 99, 258]. Anterior cervical discectomy and fusion (ACDF) with a tricorti- cal bone graft harvested from the iliac crest is the most widely used technique and has become the gold standard for the treatment of cervical radiculopathy ( Case Introduction). Fusion rates are dependent on the number of levels treated The radiological fusion rate is dependent on the amount of levels to be fused. Bohlmann et al. [33] reported a solid fusion for one, two and multilevel fusions of 89%, 73% and 67%, respectively. Cauthen et al. [49] analyzed the outcome of anterior cervical discectomy and interbody fusion (Cloward technique) in 348 patients with an average follow-up of 5 years. The fusion rate was 88% for one level and 75% for multilevel fusions. Emery et al. [78] reported a fusion rate of only 56% for three-level fusions. The surgical outcome is mainly dependent on the decompression effect Clinical outcome of ACDF for cervical radiculopathy is good to excellent in 70–90% of patients [223] and mainly dependent on the decompression of the compromised nerve root [45]. However, Bohlmann et al. have reported a signifi- cant association between the presence of non-union and postoperative neck or arm pain [33]. Degenerative Disorders of the Cervical Spine Chapter 17 449 Autograft V ersus Allograft Autograft is superior to allograft for ACDF The use of allograft for spinal fusion in conjunction with anterior decompression for degenerative cervical disorders has a long tradition. Cloward [62, 63] used allografts from the 1950s. However, there are only a few studies [7, 28, 42, 303] comparing allografts versus autografts which were analyzed in a meta-analysis [83]. Floyd and Ohnmeiss [83] concluded from their meta-analysis that for both one- and two-level anterior cervical discectomy and fusion, autograft demon- strated a higher rate of radiographic union and a lower incidence of graft col- lapse. However, it was not possible to ascertain whether autograft is clinically superior to allograft. The authors advised that the decision of the bone graft shouldnotbesolelybasedontheradiographicresultsbutthatadditionally donor site morbidity, transmission of infectious disease, quality of the autograft (osteoporosis) and patient preference must be taken into consideration [83]. Plate Fixation The conventional fusion techniques were not universally successful. Complica- tions causing persistent pain included [10, 33, 69, 78, 102, 228, 287, 288, 292, 304]: non-union (particularly for multilevel fusions) graft displacement graft collapse sagittal malalignment (kyphosis) For traumatic cervical lesions, anterior plate fixation gained widespread accep- tance because it provides immediate stability and high fusion rates [4, 31, 46]. Similarly, instrumented fusion was introduced for degenerative cervical disor- ders [156, 247, 279]. Additional plating theoretically increases the fusion rate, preserves cervical lordosis, and prevents graft subsidence and migration partic- ularly when two or more levels are involved [247]. Plate fixation increases the fusion rate for multilevel fusions However, three RCTs failed to demonstrate the superiority of additional plate fixation for one-level fusions in terms of clinical or radiological outcome [105, 244, 309]. For multilevel fusion, there is some evidence that plating appears to result in higher fusion rates [47, 94, 146, 280, 281]. Anterior plate fixation does not suffice for three-level fusions Wang et al. [281] indicated that a three-level fusion is still associated with a high non-union rate (18%), although the use of cervical plates decreased the pseudarthrosis rate. Bolesta reported that three- and four-level modified Robin- soncervicaldiscectomyandfusionresultsinanunacceptablyhighrateofpseud- arthrosis which is not improved by a cervical spine plate alone [34]. Additional posterior fixation is advocated in three and more level fusion to decrease the non-union rate [180] ( Case Study 1). Fusion with Cages One drawback of the conventional fusion (Smith-Robinson or Cloward) tech- niques could not be overcome by plating, i.e. bone graft donor side pain. Persis- Bone graft donor site pain remains a drawback of ACDF tent pain from the anterior iliac crest is reported in up to 31% of patients [110]. During the last decade, cages have become increasingly popular in stabilizing and fusing the cervical spine subsequent to anterior discectomy. Compared to conventional fusion techniques, the theoretical advantages of cages are to: restore disc height restore cervical lordosis prevent graft collapse 450 Section Degenerative Disorders ab c def Case Study 1 A 47-year-old male had experienced some numbness, clumsiness and tingling in his hands for over 1 year before he sud- denly developed gait disturbance and weakness in both legs. The patient was admitted to the Neurology Department for further diagnostic work-up. Clinically, the patient presented with an incomplete tetraparesis sub C4. A lateral radio- graph ( a) demonstrates a congenitally narrow spinal canal with cervical spondylosis particularly at the levels C5/6 and C6/7 and decrease of cervical lordosis. Sagittal T2W image ( b) demonstrating a large disc herniation at C4/5 with com- pression of the spinal cord, advanced disc degeneration with endplate changes (Modic Type II), signal intensity changes within the spinal cord at C5/6, and a disc protrusion with spinal cord compression at C6/7. Axial T2W images confirm the severe myelon compression at the levels of C4/5 ( c) and C6/7 (d). The patient underwent multilevel anterior cervical dis- cectomy and fusion with a tricortical iliac bone graft and anterior plating. In a second operation, the patient underwent posterior laminectomy and instrumented fusion to completely decompress the narrow spinal canal and spinal cord ( e, f). Postoperatively, the patient substantially improved with regard to his neurological function but a residual tetrapa- resis remained at latest follow-up. avoid donor site pain reduce operative time Many different cage designs (e.g. cylindrical, mesh, ring or box shaped) and materials (e.g. titanium, carbon, polyetheretherketone, hydroxyapatite coated) Degenerative Disorders of the Cervical Spine Chapter 17 451 have been introduced [54, 110, 144, 216, 221, 271]. Debate continues on the fact of the cage filling with bone (autograft or allograft), bone graft substitutes or void and favorable clinical results have been reported with each technique [53, 132, 157, 168, 203, 233, 248]. Cage fusions are not better than conventional ACDF Randomized studies have so far not been able to reveal a significantly better clinical outcome of patients undergoing cage fusion compared to conventional techniques [111, 210, 233, 273] although the rate of non-union appears to be higher and bone graft donor site pain lower [273]. Anterior Corpectomy In patients suffering from CSM, anterior discectomy and osteophyectomy may not suffice to sufficiently decompress the spinal cord. The spinal cord may not only be compromised by disc protrusions and spondylophytes but also by a spi- nal malalignment (kyphosis) or a narrow spinal canal. In these cases, a subtotal corpectomy is required [236]. Partial vertebral body resection and decompres- sion was first used to treat traumatic cervical disorders [91] and later adopted for degenerative disorders [114, 236]. Compared to ACDF, a median corpectomy offers the advantage of: enlarging the spinal canal allowing for a more radical decompression increasing the fusion rate Corpectomy allows forbetterdecompression and a high fusion rate A variety of techniques were developed to stabilize the cervical spine after decompression through vertebrectomy [21, 35, 113, 116, 298]. The extent to which decompression should be performed depends on the pathology and the size of the spinal canal [125, 295]. Most authors [143] advocate the complete removal of the posterior osteophytes and PLL to achieve maximum decompres- sion ( Fig. 5). Compared to multilevel ACDF, corpectomy offers the advantage of reducing the host-graft interfaces.Swanketal.[263]haveshownthatthenon- union rate of two-level ACDF was 36% while one-level corpectomy resulted in a non-union rate of 10% ( Case Study 2). Similar results were obtained by Hilibrand et al. [125], who reported a non-union rate of 34% for ACDF (one to four levels) and 7% for corpectomy. One-level corpectomies are best reconstructed using iliac crest autograft. The angulation of the iliac crest limits its applicability for longer anterior reconstruc- tions. Therefore, fibula strut allo grafts have been used with satisfactory results [263]. However, the fusion rate of allograft fibula is somewhat lower than with autograft [100, 263]. This limitation can be overcome with additional posterior instrumented fusion [180]. Recently, cages constructs have been used for long anterior column reconstructions [56, 187, 261, 268, 293]. The drawbacks of cage buttressing for anterior cervical reconstructions include subsidence, limited assessment of fusion status, and difficult revision surgery because of frequent partial incorporation [180]. Three-level corpectomies necessitate anterior- posterior fixation Anterior plating currently is recommended to increase fusion rate and decrease the incidence of graft dislocation [153]. However, the ability of plate fix- ation to stabilize a three-level corpectomy is limited [136, 242, 270] and addi- tional posterior stabilization is recommended to circumvent implant failure and non-union [73, 93, 162, 226]. Anterior Discectomy Without Fusion A drawback of the classic Robinson-Smith technique is that the intervertebral disc is removed to reach the location of the neural compromise. Attempts have 452 Section Degenerative Disorders abc de f Figure 5. Technique of corpectomy and instrumented fusion The cervical spine is exposed by an anteromedial approach. a The intervertebral discs are excised adjacent to the target level. b The medial three-thirds of the vertebral body are resected. The lateral wall is preserved to protect the vertebral arteries. c A high-speed diamond burr is used to remove the median part of the vertebral body. d The remaining part of the posterior vertebral wall is elevated away from the spinal cord and resected with a Kerrison rongeur. e Kerrison ron- geur and curettes are used to remove posterior osteophytes and decompress spinal cord and exiting nerve roots. f The spine is reconstructed by insertion of a tricortical iliac bone block and anterior plating. therefore been made to remove the disc herniation without completely resecting the intervertebral disc. Indications of this technique are: soft disc herniation disc sequestration young individual no spondylosis no segmental instability Retrospective case series did not report a clinical outcome inferior to discectomy and fusion [24, 25, 183, 192, 219, 220]. The disadvantages of this method, how- ever, were: recurrent herniation motion segment degeneration segmental instability chronic neck pain spontaneous fusion Degenerative Disorders of the Cervical Spine Chapter 17 453 ab c d ef Case Study 2 A 56-year-old male had recurrent episodes of neck pain with occasional radiating pain to his right forearm for 18 months before he developed acute onset excruciating arm pain followed by a progressive sensorimotor deficit of C6 on the right side. Lateral radiograph ( a) showing cervical spondylosis at the level of C5/6 and C6/7. Sagittal T2W image (b) reveals cer- vical spondylosis and disc protrusions at C5/6 and C6/7. Axial T2W image shows a sequestrated disc herniation at C5/6 (arrow) with compression of the exiting nerve root C6 ( c) and a disc protrusion at C6/7 with compromise of the C7 nerve root ( d). The indication for surgery was prompted by the progression of the paresis. The patient underwent a corporec- tomy of C6, decompression of the C6 and C7 nerve root, reconstruction with a tricortical iliac bone block and anterior plating ( e, f). At 1 year follow-up, the sensorimotor deficit had completely recovered. The patient was fully functional but occasionally had some episodes of benign neck pain. Outcome of discectomy without fusion is not inferior to that of ACDF In a prospective randomized study on 91 patients with single-level cervical root compression, Savolainen et al. [244] analyzed three different treatment groups: discectomy without fusion, fusion with autologous bone graft, and fusion with autologous bone graft plus plating. Clinical outcomes were good for 76%, 82%, and 73% of the patients, respectively. A slight kyphosis developed in 62.5% of the patients who had undergone discectomy, 40% of the patients who had undergone fusion, and 44% of the patients who had undergone fusion plus 454 Section Degenerative Disorders plating [244]. This study indicates that discectomy without fusion is not inferior to ACDF. Techniques were developed to preser ve the intervertebral disc,whichoftenis not substantially degenerated and can therefore be preserved. Verbiest [274] sug- gested a lateral approach while Hakuba [112] described a trans-unco-discal Disc preserving anterior nerve root decompression is feasible approach. The latter approach is a combined anterior and lateral approach to the cervical discs. Interbody fusion was not performed except for special cases with significant kyphosis or instability [112]. Minimally invasive techniques were sug- gested by Jho [140] and Saringer et al. [240], who reported on a microsurgical anterior foraminotomy which provides direct anatomical decompression of the compressed nerve root by removing the compressive spondylotic spur or disc fragment. Saringer et al. [241] modified this technique by using an endoscopic approach. Other authors removed the herniated disc under endoscopic view using a transdiscal route [13, 84]. Total Disc Arthroplasty Adjacent segment degeneration is the main argument for TDA Adjacent segment degeneration (Fig. 6) has been mentioned as the main argu- ment against spinal fusion and therefore favoring total disc arthroplasty (TDA). However, the data on adjacent segment degeneration is sparse [14, 52, 124, 160]. Hilibrand et al. [124] followed 374 patients who had a total of 409 anterior cervi- cal fusions for a maximum of 20 years. Symptomatic adjacent-segment disease occurred at an incidence of 2.9% per year during the 10 years after operation. About one-fourth of the patients who had an anterior cervical fusion were at risk of developing symptomatic adjacent segment disease within 10 years. A single- level arthrodesis involving C5/6 or C6/7 and preexisting radiographic evidence of degeneration at adjacent levels appeared to be the greatest risk factors for new abc Figure 6. Adjacent segment degeneration a Symptomatic cervical spondylosis at C5/6 with anterior and posterior osteophytes. b Postoperative lateral radiograph after anterior cervical discectomy and fusion with a tricortical iliac bone graft (Robinson-Smith technique). c Lateral radiographs at 6 years follow-up demonstrate a perfect fusion at C5/6 with remodeling of the osseus structures (arrow- heads). Note the adjacent segment degeneration at C4/5 (arrow). Degenerative Disorders of the Cervical Spine Chapter 17 455 disease [124]. Importantly, no study so far was able to differentiate the effect of natural history versus the effect of the arthrodesis on the development of adja- cent segment degeneration [52, 101]. More than 15 different designs are now under pre-clinical and clinical evalua- tion (e.g. Prestige II, Bryan, PCM, ProDisc-C, Cervicore, Discover) [199]. Current TDA designs include one-piece implants and implants with single or double glid- ing articulations with either metal-on-metal or metal-on-polymer bearing sur- ab c de Case Study 3 A 53-year-old female patient complained of persistent (4 months) right-sided shoulder/arm pain and was referred to our shoulder specialists with suspected impingement syndrome. A thorough physical examination revealed a normal shoul- der function but a decreased sensation at the lateral aspect of the radial forearm and thumb as well as weakness in dor- siflexion of the hand. The biceps tendon reflex was diminished on the right. A lateral radiograph ( a) showed segmental kyphosis at C4/5 and minimal cervical spondylosis at C5/6 and C6/7. Parasagittal T2W image ( b) revealed a lateral disc protrusion at C5/6. Axial T2W image ( c) confirms the foraminal disc protrusion with compression of the exiting C6 nerve root. Non-operative therapy (medication, physiotherapy) failed to provide persistent substantial pain relief. A nerve root block (C6) completely alleviated the symptoms for 1 week. Discectomy, nerve root decompression and total disc arthro- plasty at C5/6 was carried out ( d, e). Immediately after surgery, the patient had complete pain relief and was fully func- tional 2 weeks after surgery. At the 2-year follow-up, the patient was still completely symptom-free. 456 Section Degenerative Disorders . evidence for the effectiveness of manipulative treatment Manipulative therapy remains a mainstay of conservative treatment for degenera- tive disorders of the cervical spine. Particularly, traction has. evidence of effectiveness of epidural injection of methylprednisolone and lidocaine for chronic neck pain with radicu- lar symptoms [208]. Degenerative Disorders of the Cervical Spine Chapter 17 447 Radiofrequency. (RCT) for the use of infrared laser for the treatment of acute neck pain and chronic neck pain from four RCTs. Operative Treatment General Principles Degenerative disorders of the cervical spine