下腰椎椎间孔形态与椎间盘高度丢失的相关性研究

目的描述下腰椎椎间孔的形态及椎间盘高度丢失时椎间孔形态的变化。方法取正常的成年新鲜尸体下腰椎标本8具(L3～S1),观察标本在不同状态(椎间盘完整和椎间盘破坏)及不同加载条件(0、300、500N)下L4,5 和L5S1椎间孔的形态及其和神经根的解剖关系,测量椎间孔的高度、最大宽度、最小宽度,于X线侧位片上测量椎间盘前、后高度。结果在未加载的自然状态下,椎间孔上大下小,呈倒置的泪滴形,神经根位于椎间孔上部。在椎间盘完整的状态下,加载500N时,椎间孔形态及其与神经根关系的变化不明显。摘除髓核,随着加载量逐渐增大,椎间孔逐渐缩小、变形,神经根被推挤向同位椎弓根的下缘;椎间孔高度、最大宽度和椎间盘前高、后高逐渐减小,与未加载时比较差异有显著性(P<0.05)。经多元线性回归分析,椎间孔高度与椎间盘后高、前高呈线性相关。结论椎间盘高度丢失与椎间孔形态改变关系密切,椎间孔形态改变增加了神经根卡压的危险性。     

Cervical intervertebral disc space narrowing and size of intervertebral foramina

Computer-assisted simulation of C4-C5, C5-C6, and C6-C7 intervertebral disc space narrowing was performed on 16 anatomic specimen cervical spines to determine the relationship of the cross sectional foraminal areas with the degree of narrowing of the cervical intervertebral disc space. Compared with normal foraminal area values, reduction of 20% to 30% of the foraminal area was found after 1 mm narrowing of the intervertebral disc spaces; reduction of 30% to 40% of the foraminal area was found after 2 mm narrowing of the intervertebral disc space; and reduction of 35% to 45% of the foraminal area was found after 3 mm narrowing of the intervertebral disc space. Statistically significant differences were found among the remaining cross sectional foraminal areas after different degrees of intervertebral disc space narrowing. Compression of the nerve root within the intervertebral foramina after the collapse of the intervertebral disc space cannot be ignored, and an appropriate surgical procedure to maintain the normal height of the disc space is essential. The size of the intervertebral foramen is related directly to the height of the intervertebral disc space. A 3-mm vertical reduction of the intervertebral disc space is associated more frequently with severe narrowing of the neuroforamen.     

Small keyhole transuncal foraminotomy for unilateral cervical radiculopathy

Summary Interbody fusion after anterior discectomy may lead to acceleration of degenerative changes at adjacent levels. Although the posterior approach preserves the motion segment, decompression of the nerve root is indirect if “hard disc prolaps” is the main cause. Recently, a technique of microsurgical anterior cervical foraminotomy for the treatment of radiculopathy with preservation of the segment mobility was published. In this study, we present this technique with several modifications. Thirteen patients – 5 men and 8 women with an average age of 49 years – with unilateral radiculopathy resistant to conservative treatment underwent microsurgical anterior foraminotomy via a small keyhole transuncal approach. The base of the uncinate process (UP) was directly drilled in the trajectory to the intervertebral foramen without destroying the disc tissue. The vertebral artery between the transverse process was not exposed. Furthermore, the functional anatomy of the uncovertebral joint remained largely intact. All patients experienced complete relief of radiating pain. A cervical collar was not used. Mean follow-up time was 19 months. The mobility of the operated segment was preserved in each patient. No instability of the cervical spine was seen. The microsurgical anterior foraminotomy via a small keyhole transuncal approach is safe, minimally invasive, and represents an effective method to treat unilateral cervical radiculopathy caused by disc prolaps and/or uncovertebral osteophytes. Additionally, the segment mobility is preserved and prevents the acceleration of degenerative changes at adjacent levels.     

Radiculopathy at the C5/6 intervertebral foramen resulting in isolated atrophy of the deltoid: an aberrant innervation complicating diagnosis. Report of two cases

We present two cases in which the diagnosis was complicated by the presence of a weak muscle innervated by a compressed motor root in the intervertebral foramen (IVF) at an atypical level. The patients were 59- and 53-year-old men; they presented with marked atrophy and weakness predominantly in a unilateral deltoid. Neuroimaging revealed narrowing of the nerve root sleeve at the C5/6 IVF due to a herniated disk or osteophyte. Predominant atrophy and weakness of the deltoid were not consistent with radiculopathy at the C5/6 IVF, i.e. C6 radiculopathy. During an extended observation period to rule out motor neuron disease, their weakness did not spread and the patients underwent posterior medial facetectomy and anterior foraminotomy. This produced marked improvement of the deltoid weakness soon after the operation. We considered unexpectedly wide motor innervation of the C6 nerve root predominantly in the deltoid, anatomic variations in the C5 root such as the trunk of the C5 root entering into the C5/6 IVF, and descending anastomoses connecting the C5 and C6 rootlets as possible explanations. Awareness of this rare presentation may aid in the diagnosis and surgical management of these patients.

     

Relationship of cervical spinal rootlets and the inferior vertebral notch

The anatomic features of cervical spinal rootlets from C5 to T1 and their relationships to the inferior vertebral notches were studied. Fifteen fresh cadavers were dissected and the cervical spinal cord and spinal rootlets were exposed by posterior total laminectomy. The dorsal rootlet entry zone of each spinal root was located proximal to the inferior vertebral notch, with an increasing distance from 15 mm at C5 to 28 mm at T1. The angle sustained by the rootlets to the cord decreased from 45 degrees to 89 degrees at C5 and to 23 degrees to 41 degrees at T1. Ventral rootlet exit zones shared similar arrangements and orientations, but they could not be exposed with posterior laminectomy only. Spinal rootlets of a particular cervical spinal segment may be found medial to the pedicles or through the intervertebral foramen one level above. They may be exposed by foraminotomy or partial excision of the pedicles. The inferior vertebral notch, which is the inferior border of the pedicle, is a reliable landmark for location of the rootlets. The information is useful for safe surgical manipulation and instrumentation around the pedicles, and when reimplantation of spinal nerve roots is considered for total brachial palsy.     

单开门椎板成形术联合椎间孔切开术治疗脊髓型合并神经根型颈椎病疗效分析

目的评价颈后路单开门椎管成形术联合椎间孔切开术在治疗颈椎管狭窄症合并单侧神经根型颈椎病中的作用。方法回顾性研究2006年7月至2009年1月44例颈椎管狭窄症合并单侧神经根压迫症状患者,行颈后路单开门椎管成形术联合椎间孔切开术治疗的23例患者为A组,单纯行颈后路单开门椎管成形术治疗的21例患者为B组。引起椎间孔狭窄的原因:椎间盘突出、钩椎关节骨赘形成、关节突增生。神经根症状主要表现为单侧上肢疼痛、感觉减退、肌力下降和反射减弱。A组手术为颈后路单开门椎管成形术联合椎间孔切开术,关节突内侧缘切除范围均小于等于50%;B组仅行颈后路单开门椎管成形术。结果术后随访20～36个月,平均28个月。采用日本骨科协会评分法计算两组髓性症状术后改善率,差异无统计学意义;根性症状术后临床效果评价:A组优18例,良3例,一般2例;B组优7例,良3例,一般9例,差2例。结论对合并有单侧神经根型的颈椎管狭窄症患者,采用颈后路单开门椎管成形术联合椎间孔切开术可取得良好的手术效果。     

Posterior surgical approach to the cervical neural foramen for intervertebral disc disease

A POSTERIOR FORAMINOTOMY (hemilaminotomy and medial facetectomy) is indicated for the treatment of nerve root compression secondary to posterolateral disc herniation or spondylotic foraminal stenosis. We describe the normal and pathological anatomy of the cervical neural foramen as well as our surgical technique, which has been highly effective in cases of cervical discogenic radiculopathy.     

The anatomical mechanism of C5 palsy after expansive open-door laminoplasty

BACKGROUNDPostoperative C5 palsy is not an uncommon complication in patients who undergo expansive open-door laminoplasty. However, the etiology is unclear and likely multifactorial. Nerve root lesions and spinal cord lesions have been previously proposed theories.PURPOSETo investigate the anatomical mechanism of postoperative C5 palsy after cervical expansive open-door laminoplasty.STUDY DESIGNA dissection-based study of eight embalmed human cadavers.METHODSThe anatomy was studied in eight whole cervical cadavers (three females, five males), prepared with formaldehyde, whose ages at the time of death ranged from 54 to 78 years. Dissection was performed on the intervertebral foramen and spinal canal. In the C3–C7 of the cervical vertebra, the extraforaminal ligaments and the meningovertebral ligaments were observed. The length, width, and thickness of the ligaments were measured with a Vernier caliper. After an expansive open-door laminoplasty was performed, the shape of the dural sac was changed, and displacement of the nerve root was observed. In addition, the lengths of the anterior rootlets were measured. This study has been supported by grants from Science and Technology Planning Project of Guangdong Province (CN) (Grant No. 2017B020210010) without potential conflict of interest-associated biases in the text of the paper.RESULTSOne hundred seventy-seven extraforaminal ligaments were found to connect the spinal nerve to the surrounding structures. After an expansive open-door laminoplasty was performed, posterior distension of the dural sac and movement of the spinal cord and nerve root were found. The spinal cord was closely attached to the ligamentum flavum by meningovertebral ligaments. In addition, the length of the C5 intradural rootlets (5.81–10.59 mm) was the shortest among the vulnerable segments.CONCLUSIONTraction on and posterior movement of the extradural roots may be the main pathologic mechanism of postoperative C5 palsy when expansive open-door laminoplasty is performed. The meningovertebral ligaments and extraforaminal ligaments might play an important role in the occurrence of postoperative C5 palsy.CLINICAL SIGNIFICANCEThis study provides clinicians with a more detailed understanding of the anatomic structure and potential mechanism of C5 palsy. Consideration of the meningovertebral ligaments and the intervertebral foramen may provide new directions for reducing the incidence of this complication.     

显微内镜下颈椎后路椎间孔切开减压术的疗效探讨

目的探讨显微内镜下颈椎后路椎间孔切开减压术治疗神经根型颈椎病及颈椎间盘突出症的临床疗效。方法2004年2月-2007年6月,于显微内镜下行颈椎后路椎间孔切开减压术24例。男16例,女8例;年龄42～68岁,平均59岁。其中神经根型颈椎病16例,颈椎间盘突出症8例。病变节段:C4、58例,C5、612例,C6、74例。病程6～15个月。影像学检查显示8例颈椎间盘突出症中软性突出物6例、硬性突出物2例;神经根型颈椎病的受压因素主要为黄韧带肥厚、钩椎关节增生及关节突关节位置异常。根据日本骨科协会(JOA)脊髓功能评分法评定为(12.60±1.52)分。结果手术时间90～120min,平均100min;术中出血量100～150mL,平均120mL。1例全麻手术患者术中为切除钙化的突出髓核组织造成神经根牵拉伤,术后采用甲泼尼龙冲击治疗后3个月神经根功能恢复;其余患者术后神经根疼痛症状明显改善19例,减轻4例。术后影像学检查显示手术部位减压彻底。24例均获随访,随访时间24～36个月,平均28个月。X线片及CT检查示椎间高度无明显丢失,生理曲度正常。术后24个月根据JOA脊髓功能评分法评定为(16.10±0.29)分,与术前比较差异有统计学意义(P0.01)。结论显微内镜下颈椎后路椎间孔切开减压术可通过小切口快捷进入术区,减少了组织损伤,避免了椎间高度丢失,临床疗效优良。     

Cervical transforaminal injection and the radicular artery: variation in anatomical location within the cervical intervertebral foramina

BACKGROUND: Recent articles have detailed the adverse events associated with transforaminal steroid injections into the radicular arteries. Guidelines on strict transforaminal epidural techniques have been described to limit complications. There remains limited information regarding the cervical level of entry, location within the intervertebral foramina, and prevalence of the radicular arteries within the population. METHODS: With the aid of premortem angiography and postmortem latex-injected vasculature, a single detailed cadaveric dissection was performed to elucidate the specific anatomic location of the radicular arteries within the intervertebral foramina and the anastomoses of the arteries to the anterior spinal artery. RESULTS: Five radicular arteries (C5, C6, two at C7, C8) were traced entering the foramina either anteriorly or posteriorly to supply the anterior and posterior spinal arteries. Radicular arteries received blood supply from either the deep cervical (C8) or vertebral arteries. The C8 radicular artery entered the lateral aspect of the foramen and penetrated the dural sleeve within the inferior portion of the foramen, directly inferior to the exiting spinal nerve, to supply the anterior spinal artery. This artery was of a large enough caliber to be entered by a 22-gauge needle. CONCLUSIONS: A larger population is necessary to characterize the range of anatomic variations in arterial supply within the foramina. Available studies support the current technique of fluoroscopic needle insertion. Yet, there is wide anatomic variation in the origin and location of these vessels, and even with strict adherence to technique, it is feasible that a properly placed needle could penetrate a radicular artery.     

颈椎管扩大成形椎间孔切开减压治疗颈神经根病

目的评价颈椎管扩大成形椎间孔切开减压手术在治疗颈神经根病中的作用. 方法 1996年～2000年治疗29例有颈神经根压迫症状患者,其中男16例,女13例;年龄38～72岁,平均59岁.引起椎间孔狭窄的原因:椎间盘脱出、钩椎关节骨赘形成、椎管狭窄 黄韧带肥厚和关节突增生.最常受累的椎间孔为C5、6、C6、7.主要表现为双上肢感觉减退、肌力下降和反射减弱.手术为椎管扩大成形椎间孔切开减压,其中Ⅰ度减压13例(次),Ⅱ度减压21例(次). 结果术后随访15～29个月,平均22个月.感觉减弱最先恢复,效果最为理想;其次为肌力恢复,腱反射恢复最慢,效果也最差.术后效果评价:优24例;良4例;一般1例. 结论对合并有椎间孔狭窄的颈椎病患者,采用颈椎管扩大成形加椎间孔切开减压可取得良好的手术效果.     

无症状腰椎间盘突出再认识

腰椎间盘突出症确切致痛机制尚未完全明了，脊神经根的机械性压迫被认为与疼痛和特定节段神经功能障碍有关，然而无症状腰椎间盘突出的现象对此提出不同的解释。该文对近年来有关无症状腰椎间盘突出的机制进行了系统的研究，认为其与椎间盘突出物可代偿的椎管储备容量、受累神经根对机械压迫的逃逸避让与弹性延长功能，以及受累神经根低氧消耗与抗缺血性损伤代偿作用等因素有关。这将深化对下腰痛的理解并有助于相关领域的继续研究。     

Modified transcorporeal anterior cervical microforaminotomy for cervical radiculopathy: a technical note and early results

A prospective analysis of the first twenty patients operated for cervical radiculopathy by a new modification of transcorporeal anterior cervical foraminotomy technique. To evaluate early results of a functional disc surgery in which decompression for the cervical radiculopathy is done by drilling a hole in the upper vertebral body and most of the disc tissue is preserved. Earlier approaches to cervical disc surgery either advocated simple discectomy or discectomy with fusion, ultimately leading to loss of motion segment. Posterior foraminotomy does not address the more common anterior lesion. Twenty patients suffering from cervical radiculopathy not responding to conservative treatment were chosen for the new technique. Upper vertebral transcorporeal foraminotomy was performed with the modified technique in all the patients. All the patients experienced immediate/early relief of symptoms. No complications of vertebral artery injury, Horner’s syndrome or recurrent laryngeal nerve palsy were noted. Modified transcorporeal anterior cervical microforaminotomy is an effective treatment for cervical radiculopathy. It avoids unnecessary violation of the disc space and much of the bony stabilizers of the cervical spine. Short-term results of this technique are quite encouraging. Longer-term analysis can help in outlining the true benefits of this technique.     

Exclusively epidural arteriovenous fistula in the cervical spine with spinal cord symptoms: case report

OBJECTIVE AND IMPORTANCE: We describe the case of an epidural arteriovenous fistula (AVF) in the cervical spine draining only into the epidural and paravertebral plexus. An entirely epidural AVF having such drainage is extremely rare. CLINICAL PRESENTATION: A 24-year-old man presented with a 4-month history of gradually progressive sensory and motor disturbances of the upper and lower extremities. Magnetic resonance imaging and magnetic resonance angiography revealed a peridural vascular lesion within the canal compressing the spinal cord from C5 to T2. Diagnostic angiography revealed a perimedullary and/or dural high-flow AVF, fed mainly by branches of ascending cervical and deep cervical arteries. The fistula drained into the epidural and paravertebral venous plexus without reflux into intradural venous systems. INTERVENTION: Multiple feeders of the AVF were embolized with a Liquid coil and n-butylcyanoacrylate via a two-step procedure. One week after embolization, the AVF was surgically removed. CONCLUSION: Interesting points of this case were the exclusively epidural location of the lesion, the exclusively epidural drainage of the AVF, and the etiology of the symptoms. Venous drainage of the fistula had no relation to any dural or intradural veins. Initially, spinal cord and nerve root compression by extradural veins with varicose dilation seemed to cause the radiculopathy and/or the myelopathy, and subsequent myelopathy caused by spinal venous hypertension was believed to be the main etiology in this case.     

Anatomic relation between the cervical pedicle and the adjacent neural structures

STUDY DESIGN: An evaluation of the anatomic relation between the cervical pedicles and the adjacent neural structures. OBJECTIVES: To determine quantitatively the antomic relation of the cervical pedicles to the adjacent nerve roots and dural sac. SUMMARY OF BACKGROUND DATA: Transpedicular screw fixation in the cervical spine has been reported, but little quantitative data regarding the anatomic relation between the cervical pedicles and the surrounding neural structures are known. METHODS: Twenty cadavers were used for dissection to observe the relations of the cervical pedicles to the adjacent dural sac and nerve roots. After removal of whole posterior bony elements including the spinous processes, laminas, and lateral masses, the isthmus of the pedicles, the dural sac, and the nerve roots of C3-C7 were exposed. Direct measurements included the distance from the pedicle to the superior and inferior nerve roots and the dura. Also, the pedicle height and width were measured at its isthmus. RESULTS: No distance was found between the pedicle and the superior nerve root, nor between the pedicle and the dural sac at C3-C7 for all specimens. The mean distances between the pedicle and the inferior nerve roots for all specimens ranged from 1.4 to 1.6 mm. The mean pedicle heights and widths for all specimens at C3-C7 ranged from 6.0 to 6.5 mm and 4.7 to 5.3 mm, respectively. A significant difference between male and female specimens was noted in the pedicle heights for all levels measured (P = 0.001), and in the pedicle widths for the levels of C4 and C6 (P = 0.05). CONCLUSIONS: This study suggests that the incidence of neurologic injuries may be higher in screw penetration of the medial or superior cortex of the pedicle than in screw penetration of the inferior cortex of the pedicle.     

Pathoanatomy and pathophysiology of nerve root compression

The anatomy and physiology of the nerve root complex in the lumbar spine are reviewed, with special reference to the effects of mechanical deformation of nerve roots in association with intervertebral disc herniation and spinal stenosis. Biomechanical aspects of nerve root deformation induced by compression are discussed. The functional changes induced by compression can be caused by mechanical nerve fiber deformation but also may be a consequence of changes in nerve root microcirculation, leading to ischemia and formation of intraneural edema. Nerve root compression can, by different neurophysiologic mechanisms, induce motor weakness and altered sensibility or pain. Intraneural edema and demyelination seem to be critical factors for the production of pain in association with nerve root compression.     

Origin of lumbar spinal roots and their relationship to intervertebral discs: a cadaver and radiological study

Previous studies on the anatomy of the lumbar spine have not clarified the precise relationship of the origin of the lumbar roots to their corresponding discs or their angulation to the dural sac. We studied 33 cadavers (25 formalin-preserved and eight fresh-frozen) and their radiographs to determine these details. All cadavers showed a gradual decrease in the angle of the nerve root from L1 to S1. The origin of the root was found to be below the corresponding disc for the L1 to L4 roots. In the formalin-preserved cadavers 8% of the L5 roots originated above, 64% below and 28% at the L4/L5 disc. In the fresh cadavers the values were 12.5%, 62.5% and 25%, respectively. For the S1 root 76% originated above and 24% at the L5-S1 disc in the formalin-preserved cadavers and 75% and 25%, respectively, in the fresh cadavers.A herniated disc usually compresses the root before division of the root sleeve. Thus, compression of the thecal sac before the origin of the root sleeve is common for L1 to L5 whereas compression at the root sleeve is common for S1. Our findings are of value in understanding the pathophysiology of prolapse of the disc and in preventing complications during surgery.     

Headache in patients with cervical radiculopathy: a prospective study with selective nerve root blocks in 275 patients

Since many years we routinely use diagnostic selective nerve root blocks (SNRB) at our department when evaluating patients with cervical radiculopathy. Frequently patients who also presented with headache reported that the headache disappeared when the nerve root responsible for the radicular pain was blocked with local anaesthetics. Headache has been described as a companioning symptom related to cervical radiculopathy but has never before been evaluated with SNRB performed in the lower cervical spine. For this reason we added to our routine an evaluation of the response from the SNRB on headache in patients with cervical radiculopathy. The aim was to describe the frequency of headache in patients with cervical radiculopathy and its response to a selective nerve root block of the nerve root/roots responsible for the radiculopathy. Can nerve root compression in the lower cervical spine produce headache? In this consecutive series of 275 patients with cervical radiculopathy, 161 patients reported that they also suffered from daily or recurrent headache located most often unilaterally on the same side as the radiculopathy. All patients underwent a careful clinical examination by a neurosurgeon and a MRI of the cervical spine. The significantly compressed root/roots, according to the MRI, underwent SNRB with a local anaesthetic. The effect of the nerve root block on the radiculopathy and the headache was carefully noted and evaluated by a physiotherapist using visual analogue scales (VAS) before and after the SNRB. All patients with headache had tender points in the neck/shoulder region on the affected side. Patients with headache graded significantly more limitations in daily activities and higher pain intensity in the neck/shoulder/arm than patients without headache. After selective nerve root block, 59% of the patients with headache reported 50% or more reduction of headache and of these 69% reported total relief. A significant correlation was seen between reduced headache intensity and reduced pain in the neck, shoulder and arm. The result indicates that cervical root compression from degenerative disease in the lower cervical spine producing radiculopathy might also induce headache.     

Radiological Investigations and Intra-operative Evoked Potentials for the Diagnosis of Nerve Root Avulsion: Evaluation of Both Modalities by Intradural Root Inspection

Summary  Fourteen patients with traumatic brachial plexus injuries underwent intradural inspection of cervical nerve roots to evaluate radiological and intra-operative electrophysiological findings concerning cervical nerve root avulsion from the spinal cord. Four neurosurgeons of our department assessed independently from each other both myelography and CT-myelography concerning intradural nerve root lesions. Each neurosurgeon assessed a total of 26 cervical nerve roots. Two investigators assessed 6/26 and 2 investigators 7/26 nerve roots falsely concerning ventral or/and dorsal root lesions compared with the findings on intradural inspection (23% and 27% false findings). There was a considerable variance concerning the assessibility and findings among the 4 neurosurgeons. Reconstructive surgery was performed after a mean interval of 6.5 months following trauma and 2 weeks following intradural inspection. After exposure of the brachial plexus and the cervical nerve roots in question via a ventral approach, 13 cervical nerve roots were stimulated electrically close to the neuroforamen and cortical evoked potentials (root-SEPs) were recorded from the contralateral postcentral region. All 5 roots with SEPs were intact (no root lesion) and all 8 roots without SEPs showed interrupted (ventral or/and dorsal) rootlets on intradural inspection. Our results demonstrate that false radiological findings concerning root lesions are possible. Intra-operative root-SEPs seem to be a useful aid for evaluation of cervical nerve root lesions. However, more electrophysiological data are necessary to ascertain, if this modality is able to replace intradural inspection in unclear radiological cases in the future.