应用C1-2螺钉棒系统行后路复位、固定和融合治疗合并寰-枢椎脱位的颅底凹陷症

目的探讨应用C1-2螺钉棒内固定系统行后路复位、固定和融合治疗寰枢椎脱位的手术疗效。方法 2013年4月至2013年10月,对30例我科收治的合并寰枢椎脱位的颅底凹陷症患者采用寰椎侧块螺钉和枢椎椎弓根峡部螺钉(或下关节突螺钉、颈3椎弓根螺钉)棒内固定系统进行复位、固定并取髂后上嵴松质骨植骨融合。通过术后3D-CT评判复位程度,JOA评分评判临床疗效,并探讨影响手术效果的因素。结果 30例患者中26例达到完全复位,4例为部分复位。其中25例完成了3个月以上随访,CT显示植骨愈合良好,未出现植骨的吸收及内固定的松动。结论 C1-2椎弓根钉棒内固定系统对治疗合并寰枢椎脱位的颅颈交界区畸形可以获得满意的疗效,安全可行。     

Odontoid compression of the brainstem without basilar impression-- "odontoid invagination".

We report five patients with odontoid invagination, in which the odontoid process bulges upward into the foramen magnum and compresses the brainstem without deformity of the occipital bone. Two patients had a craniovertebral abnormality associated with Chiari malformation without instability of the craniovertebral junction (stable odontoid invagination). The other three patients had dislocation of the craniovertebral junction due to iatrogenic destruction of the occipital condyle, rheumatoid arthritis or an anomaly of C2 (unstable odontoid invagination). Patients with stable odontoid invagination underwent a transoral odontoidectomy followed by occipitocervical fixation. Those with unstable odontoid invagination underwent cervical traction followed by posterior fixation in reducible cases, while in irreducible cases odontoidectomy with subsequent occipitocervical fixation was performed. Decompression of the neuraxis together with symptomatic improvement was achieved in all patients and none became unstable or developed new symptoms during follow-up ranging from 3 to 15 years.     

Atlantoaxial joint distraction as a treatment for basilar invagination: a report of an experience with 11 cases

Objective: A novel method of treatment of basilar invagination that involves distraction of the atlantoaxial joint using specially designed spiked spacers is described. Bone graft that is additionally placed within the appropriately prepared atlantoaxial joint and posterior to the arch of atlas and lamina of C2 provides bony fusion. Materials and Methods: Between December 2002 and April 2007, 11 patients underwent the discussed method of fixation at the Department of Neurosurgery, King Edward Memorial Hospital in Mumbai, India. All 11 patients had "congenital" basilar invagination and the symptoms were progressive in nature. Results: The mean follow-up period was 21 months (range 8-40 months). Neurological improvement and successful distraction with atlantoaxial stabilization and ultimate bone fusion was achieved in all the patients and was documented with dynamic radiography. There were no neurological, vascular, or infective complications. Conclusions: We conclude that the described method of atlantoaxial joint distraction and fixation provides an alternative treatment strategy for cases with basilar invagination. "Joint distraction" as a stand-alone method could provide reduction of basilar invagination and firm stabilization in such cases.     

Craniovertebral fixation … a new technique of occipital – cervical fixation

Background: Craniovertebral instability following transoral odontoid excision is usually treated by posterior occipital–cervical fixation using occipital plate and cervical lateral mass fixation with screw rod construct. A patient previously operated for basilar invagination had postoperative infection of both the transoral wound and the posterior implant site which needed removal of the posterior implant earlier.

Clinical presentation: The patient presented with severe neck pain, myelopathy, and chronic discharging sinus in the posterior lower aspect the previous neck surgery wound. Reimaging revealed incomplete odontoid excision. He underwent repeat transoral odontoid excision. Treatment of the instability needed occipitocervical fixation avoiding, the atlas, axis (weakened by infection and previous implants), and the infected posterior cervical wound. A new technique using a customized plate rod construct, fixed anteriorly to the mid cervical vertebrae (by a standard mid cervical exposure) with the rods contoured to reach posteriorly through the safe paraspinal corridor and connected with domino connectors to occipital plate rods fixed on either side of midline by additional posterior exposure avoiding the midline scar was planned and executed successfully.

Conclusion: This construct transfers the weight of the cranium to the cervical vertebral bodies along the physiological line of weight transmission and can be considered for distraction and reduction of basilar invagination with atlantoaxial dislocation. The technique seems to be safe and reproducible, but will need to tested over time with more cases.     

Craniovertebral realignment for basilar invagination and atlantoaxial dislocation secondary to rheumatoid arthritis

OBJECTIVE: We present our experience of treating nine consecutive cases of rheumatoid arthritis involving the craniovertebral junction by atlantoaxial joint manipulation and attempts towards restoration of craniovertebral region alignments. MATERIAL AND RESULTS: Between November 2001 and March 2004, nine cases of rheumatoid arthritis involving the craniovertebral junction were treated in our department of neurosurgery. Six patients had basilar invagination and 'fixed' atlantoaxial dislocation and three patients had a retroodontoid process pannus and mobile and incompletely reducible atlantoaxial dislocation. The patients ranged from 24 to 74 years in age. Six patients were males and three were females. Neck pain and spastic quadriparesis were the most prominent symptoms. Surgery involved attempts to reduce the atlantoaxial dislocation and basilar invagination by manual distraction of the facets of the atlas and axis. Reduction of the atlantoaxial dislocation and of basilar invagination and stabilization of the region was achieved by placement of bone graft and metal spacers within the joint and direct inter-articular plate and screw method of atlantoaxial fixation. Following surgery all the patients showed symptomatic improvement and restoration of craniovertebral alignments. Follow-up ranged from four to 48 months (average 28 months). CONCLUSION: Manipulation of the atlantoaxial joints and restoring the anatomical craniovertebral alignments in selected cases of rheumatoid arthritis involving the craniovertebral junction leads to remarkable and sustained clinical recovery.     

合并寰枢椎脱位的复杂颅颈交界区畸形后路减压复位内固定术疗效初步观察

目的 总结合并寰枢椎脱位的复杂颅颈交界区畸形经后路减压复位内固定术的临床经验.方法 回顾分析18 例合并寰枢椎脱位的复杂颅颈交界区畸形患者(先天性寰枢椎脱位15 例、经口腔入路齿状突磨除术后症状加重致枕颈失稳1 例、外伤所致2 例)的临床资料.施行经后路减压复位钉棒内固定术,术中行体感诱发电位及肌电图监测,根据日本骨科协会(JOA)17 分评分系统和影像学改善程度评价手术疗效.结果 术后影像学检查显示,18 例中16 例钉棒内固定系统和寰枢椎复位良好,1 例复位不良;骨性融合良好16 例,欠佳1 例.术后临床表现均不同程度好转,1 例突发呼吸骤停死亡.术后平均随访6.62 个月(3 ~ 28 个月),JOA 平均评分为11.62 ± 3.23,与手术前评分(7.51 ± 3.82)相比,差异具有统计学意义(t = - 5.476,P = 0.004).结论 经后路减压、复位、钉棒内固定术治疗合并寰枢椎脱位的颅颈交界区畸形临床疗效良好,能够减少患者痛苦、避免再次手术,值得临床推广应用.     

Rigid variety occiput/C1–C2–C3 internal fixation in pediatric population

Purpose

The purpose of this study was to review our experience of rigid internal fixation of craniovertebral junction in pediatric population. A new technique of reduction of basilar invagination with atlantoaxial dislocation is described. To the best of our knowledge and available scientific literature, this technique has not yet been described in younger patients.

Methods

We have managed 27 children by rigid variety of occiput/C1–C2–C3 internal fixation of various craniovertebral junction pathologies. All patients were subjected to thin cuts of computed tomography with 3D reconstruction for selecting appropriate rigid construct. Eight children had occiput-C2, 3 had occiput-C2–C3, and 16 had C1-C2 hardware constuct. One patient of C1–C2-plate fixation had section of C2 nerve root ganglia. Basilar invagination with atlantoaxial dislocation was reduced by new distraction/compression techniques.

Results

Improvement in clinical features and correction of deformity with solid hardware construct were seen in all patients. Follow-up period ranged from 5–72 months. One patient was lost to follow-up, and one case died of compression of vertebral artery at C1 lateral mass. Patients of myelopathy had recovery rate of 90.9 %. Hardware failure was seen in one patient, and wound infection was observed in two cases.

Conclusions

Rigid variety of occiput/C1–C2 internal fixation is a safe and effective method in the management of variety of craniovertebral pathologies in pediatric population. This new technique of reduction of basilar invagination with atlantoaxilal dislocation from posterior approach may alleviate the need of high morbity associated with surgical procedure like transoral odontoidectomy in younger patients.     

显微镜下经口腔复位内固定术治疗颅底凹陷合并寰枢椎脱位

目的 探讨经口腔入路松解、复位内固定术在颅底凹陷合并寰枢椎脱位治疗中的应用价值,并评价其有效性及安全性.方法 对3 例不可复性寰枢椎脱位患者实施显微镜辅助下经口腔入路松解、复位内固定术,术中以经口腔复位内固定钛板作为前方固定,自体颗粒骨植骨.采用日本骨科协会(JOA)17 分评分系统进行手术前后颈脊髓神经功能评价,MRI 及X 线判断术后寰枢间距及延髓颈髓角改善程度.结果 3 例患者手术平均时间为130 min(110、130 和150 min);平均出血量为150 ml(100、200 和150 ml).术后CT 检查显示,3 例患者内固定钛板及12 枚椎弓根钛钉固定理想、无松动迹象,颅底凹陷及寰枢关节脱位得到不同程度纠正;颈脊髓神经功能明显改善,JOA评分改善率分别为75.00%、40.00%和56.25%,平均改善率为57.08%,平均JOA 评分改善率评级为良好.其中1 例患者术后并发颅内感染,经对症治疗痊愈.结论 显微镜辅助下经口腔入路松解、复位内固定术治疗颅底凹陷合并寰枢椎脱位具有一定临床应用价值.     

后路复位内固定并颅后窝小骨窗减压治疗合并颅底凹陷、寰枢椎脱位和脊髓空洞症的ChiariⅠ型畸形

研究背景ChiariⅠ型畸形为颅颈交界区软组织畸形,可合并其他复杂骨性畸形如寰枢椎脱位、颅底凹陷、扁平颅底及寰枕融合等.对这些复杂畸形,目前尚无成熟的治疗方法.本文探讨颅后窝小骨窗减压并Ⅰ期经后路复位内固定术治疗合并颅底凹陷、寰枢椎脱位和脊髓空洞症的ChiariⅠ型畸形的临床疗效.方法 回顾分析2004 年7 月-2011 年9 月治疗的寰枢椎脱位和颅底凹陷患者临床资料,分别采用日本骨科协会(JOA)17 分评分系统和MRI 影像学数据评价颈脊髓功能和脊髓空洞改善程度.结果 根据纳入标准,共筛选14 例符合入组条件的患者,男性4 例,女性10 例;平均年龄为(31.86 ±11.36)岁.术前JOA 评分平均为13.07 ± 1.59,术后增加至15.57 ± 1.02,二者比较差异具有统计学意义(t = 9.946,P = 0.000);术前脊髓空洞大小平均为(7.05 ± 1.98)mm,术后缩小至(2.21 ± 1.91)mm,手术前后比较差异亦有统计学意义(t = 7.271,P = 0.000).手术后无一例发生并发症或死亡.结论 经后路复位内固定联合颅后窝小骨窗减压术治疗合并脊髓空洞症、寰枢椎脱位及颅底凹陷的ChiariⅠ型畸形能够显著改善患者预后、缩小脊髓空洞.     

经口齿状突切除联合后路枕颈融合治疗颅底凹陷畸形

目的探讨显微镜下经口齿状突切除联合枕颈融合治疗颅底凹陷畸形的方法、疗效以及并发症。方法回顾性分析昆明医科大学第二附属医院神经外科从2012年9月至2017年5月收治的12例齿状突突压迫延髓及上颈髓腹侧病人的临床资料,其中单纯颅底凹陷1例,颅底凹陷伴Chiari畸形7例,颅底凹陷伴寰枕融合4例,12例患者均行经口齿状突切除联合枕颈植骨融合手术治疗,术后长期跟踪随访,根据影像学参考数值作统计学分析。结果经过6月至2年的随访,术后症状明显缓解8例,肢体感觉无变化3例,1例2月后出现脑脊液漏,经过修补和皮瓣转移治愈,无1例患者出现伤口感染,同时测量每例患者术前及术后影像学上钱氏线,麦氏线,韦氏线,Klaus高度指数、延颈髓角及颅底角的影像学参数值变化,并将影像学数值进行统计学分析,结果提示达到显著统计学意义(P0.01)。结论经口齿状突切除术是治疗齿状突压迫延髓及上颈髓腹侧病变直接有效的手术方法,术中充分磨除齿状突和必要的固定能够促进患者的治愈,提高患者的生活质量。     

后路枕颈固定复位减压术治疗颅底凹陷症的疗效分析

目的 探讨后路枕颈固定复位减压术治疗颅底凹陷症的效果。方法 回顾性分析2015年6月至2020年1月采用单一后路枕颈固定复位减压术治疗的70例颅底凹陷的临床资料。记录病人报告的日本骨科学会（PRO-JOA）评分,用ΔPRO-JOA判断恢复程度,ΔPRO-JOA=（术后PRO-JOA评分-术前PRO-JOA评分）/（17-术前PRO-JOA评分）×100%,其中≥60%为手术效果较好,<60%为手术效果一般。结果 70例中,A型颅底凹陷[有寰枢椎脱位,寰椎齿状突间距（ADI）≥3 mm]28例,B型颅底凹陷症（无寰枢椎脱位,ADI<3 mm）42例。70例顺利完成手术,无手术死亡病例。70例术后随访12～60个月,平均（36.2±10.3）个月。A型末次随访,24例（85.71%）手术效果较好,4例手术效果一般。B型末次随访,33例（78.57%）手术效果较好,9例手术效果一般。结论 后路固定复位减压术治疗颅底凹陷症,A型和B型都可获得良好的疗效。     

Evoked potentials in diagnosis of ischemic brain stem lesions

We present an overview on the impact of evoked potentials in diagnosis of ischemic brainstem lesions. Brainstem auditory evoked potentials and somatosensory evoked potentials depict abnormalities, whereas visual evoked potentials are normal in most cases. In patients with basilar artery thrombosis and primary pontine hemorrhage these evoked potentials are mostly abnormal and can indicate the location of the lesion. Furthermore, they are of prognostic value. Whether evoked potentials are abnormal in strokes with branch occlusion of the basilar artery, depends on the location of the infarction. In infarctions of the basis pontis BAEP and SEP may be normal. Hemiparesis in brainstem strokes are associated with abnormalities in transcranial magnetic stimulation. However, no further evaluation of the level of the pyramidal tract lesion is possible by this method. During fibrinolytic therapy of basilar artery thrombosis a continuous monitoring is possible by means of BAEP. Thus, information can be obtained that is not available from neurological examination of the patient under sedative drugs.     

后路复位内固定并颅后窝小骨窗减压治疗合并颅底凹陷、寰枢椎脱位和脊髓空洞症的ChiariI型畸形

研究背景ChiariI型畸形为颅颈交界区软组织畸形,可合并其他复杂骨性畸形如寰枢椎脱位、颅底凹陷、扁平颅底及寰枕融合等。对这些复杂畸形,目前尚无成熟的治疗方法。本文探讨颅后窝小骨窗减压并I期经后路复位内固定术治疗合并颅底凹陷、寰枢椎脱位和脊髓空洞症的ChiariI型畸形的临床疗效。方法回顾分析2004年7月-2011年9月治疗的寰枢椎脱位和颅底凹陷患者临床资料,分别采用日本骨科协会（JOA）17分评分系统和MRI影像学数据评价颈脊髓功能和脊髓空洞改善程度。结果根据纳入标准,共筛选14例符合入组条件的患者,男性4例,女性10例;平均年龄为（31．86±11．36）岁。术前JOA评分平均为13．07±1．59,术后增加至15．57±1．02,二者比较差异具有统计学意义（t=9．946,P=0．000）;术前脊髓空洞大小平均为（7．05±1．98）mm,术后缩小至（2．21±1．91）mm,手术前后比较差异亦有统计学意义（t=7．271,P=0．000）。手术后无一例发生并发症或死亡。结论经后路复位内固定联合颅后窝小骨窗减压术治疗合并脊髓空洞症、寰枢椎脱位及颅底凹陷的ChiariI型畸形能够显著改善患者预后、缩小脊髓空洞。     

Vertical atlantoaxial dislocation as a cause of failure of midline fixation

We report an 11-year-old girl who had previously undergone an operation for basilar invagination involving a foramen magnum decompression and midline wire fixation. After improving initially, her neurological condition worsened again. Repeated investigations showed a firm midline craniovertebral fixation and bone fusion. However, she was found to have a vertical mobile and reducible atlantoaxial dislocation. Treatment of the vertical dislocation by lateral mass fixation resulted in lasting relief from her symptoms. Vertical instability at the atlantoaxial joints needs to be identified and appropriately treated as it may be a cause of failure of midline fixation.     

High cervical C3-4 'disc' compression associated with basilar invagination

A 20-year-old male had torticollis and short neck since birth. He presented with symptom of progressive quadriparesis over a two-year period. Investigations revealed basilar invagination with marked rotation in the craniovertebral region and relatively large C3-4 region osteophytes. Serial MRI over two years showed persistent signal opposite C3-4 disc space suggestive of cord compression. Although the cord was humped over the odontoid process, there was no clear radiological evidence that the cord was compromised at this level. During surgery, instability was identified only at the craniovertebral region and not at the level of C3-4. Distraction of the lateral masses of atlas and axis and fixation using interarticular spacers and bone graft and direct screw implantation in the lateral mass of the atlas and pars of the axis resulted in reduction of the basilar invagination and of atlantoaxial dislocation. The patient had marked clinical recovery, despite the fact that no direct procedure was done for C3-4 disc decompression. The case suggests that C3-4 disc changes could be secondary to primary instability at the craniovertebral junction.     

Management of craniocervical junction dislocation

The discovery of a craniocervical junction malformation requires management in three steps: (1) The patterns must be recognized using tomographic measurements (Chamberlain's line, Wackenheim's line). Dynamic flexion-extension studies are necessary to assess stability or instability. Stable patterns range from platybasia to basilar invagination, with gradual deformation, and are frequently associated with Chiari malformation. Unstable patterns characterized by odontoid instability are the equivalent of an odontoid fracture. The origin is malformative (hypoplasia, aplasia of the dens, os odontoidum), but the last may be difficult to distinguish from an old odontoid fracture. They are found in many syndromes (Down, Morquio, etc.). Unstable atlantoaxial patterns with atlas assimilation are hardly reducible; they evolve toward progressive instability. (2) The neurological consequences must be defined from the clinical features of the spinal cord and the cranial nerves. Both static and dynamic MRI scans must be performed; in this way identification of the neural abnormalities (hydromyelia, Chiari, etc.) and of the osseous compression is possible. (3) The most appropriate operative procedure must be selected: stable platybasia with a nervous compression by Chiari is cured only by posterior decompression; odontoid instability is cured by reduction and posterior fixation, using hooks and autologous bone grafts on the posterior arches of C-1 and C-2. Sometimes a transarticular screw fixation of C1-2 is necessary if there is a defect on the C-1 posterior arch. Craniocervical dislocations with assimilation of the atlas require posterior occipito-vertebral bony fixation with grafts and external halo immobilization or internal fixation with hooks or screws, with anterior transoral decompression in a second step.     

CT, somatosensory and brainstem auditory evoked potentials in the early prediction of functional outcome in putaminal hemorrhage

The CT and median somatosensory and brainstem auditory evoked potentials (SEP and BAEP) were studied in 80 patients with spontaneous putaminal hemorrhage for their values in the early prediction of functional outcome. The CT scan was performed within 2 days and EPs within a week after the onset of symptoms. The activities of daily living was assessed at 6 months. Patients with good functional recovery had the following findings: 1) the hemorrhage had not involved the thalamus or the posterior limb of the internal capsule; 2) the SEPs were normal or had prolonged central conduction time; and 3) the BAEP was normal. When the cortical SEPs were absent, the majority of patients were moderately or severely disabled. Attenuation or absence of BAEP wave V always forecast a grave prognosis. It is concluded that the combined use of CT, SEP and BAEP is an objective and reliable method for the early prediction of functional outcome in patients with putaminal hemorrhage.     

Atlantoaxial manual realignment in a patient with traumatic atlantoaxial joint disruption

We report a patient with complex traumatic translatory atlantoaxial dislocation, who we treated by joint exposure and reduction of the dislocation by facet manipulation and subsequent plate and screw atlantoaxial fixation. A 28-year-old male had fallen 7.6 m (25 feet), and following the fall had severe neck pain but no neurological deficit. Investigations revealed a fracture at the base of the odontoid process and posterior displacement of the entire atlas over the axis, resulting in a translatory atlantoaxial dislocation. Head traction failed as he developed severe vertigo following its application. The patient was operated upon in a prone position. We opened the atlantoaxial joint and realigned the facets using distraction and manipulation techniques and secured the joint using a plate and screw interarticular method. The patient tolerated the treatment well and was symptom-free after 28 months. Postoperative images showed good craniovertebral alignment. Although technically challenging, direct manipulation of the facets of the atlas and axis can result in excellent craniovertebral realignment.     

Evaluation of patients with multiple sclerosis by evoked potentials and magnetic resonance imaging: a comparative study

We compared the diagnostic usefulness of evoked potential (EP) studies and magnetic resonance imaging (MRI) in the evaluation of 27 patients with definite or probable multiple sclerosis (MS). MRI scans demonstrated multiple lesions in 21 patients whereas EP studies showed multiple abnormalities in 14 patients (4 of whom had only somatosensory EP abnormalities). Eighteen patients had similar MRI and EP results (e.g., normal or multiple abnormalities), 8 had multiple abnormalities shown by MRI but normal or single-modality abnormal EPs, and 1 had multiple abnormal EPs but a normal MRI scan. There was no significant difference in the sensitivity of the two techniques in detecting multiple lesions in the patients with definite MS, whereas among those with probable MS, MRI had a significantly higher yield. Seventeen patients showed clinical evidence of posterior fossa involvement, 6 patients had abnormal brainstem auditory evoked potentials (BAEPs), and 4 patients had areas of increased signal intensity revealed by MRI of the brainstem. There was no clinical evidence of brainstem involvement in 2 patients with BAEP abnormalities, 2 with an abnormal posterior fossa shown by MRI, and one patient with abnormalities shown by both BAEP and MRI. We conclude that MRI is more sensitive in detecting multiple lesions than are multimodality EP studies, but that BAEP assessment may be slightly more sensitive than MRI in detecting brainstem lesions.     

Monitoring of sensory evoked potentials during surgery of skull base tumours

Despite advances in instrumentation and the use of microsurgical techniques, neurosurgical procedures involving extensive areas of skull base or other critical areas of brain still carry significant risk for neurological injury. The use of intraoperative recording of sensory evoked potentials (SEP) has been advocated to monitor neurologic function during these major neurosurgical procedures to reduce the risk of injury to neural structures. This report summarizes our experience with intraoperative monitoring of SEP in over 200 patients, and details our findings in a group of 12 patients with skull base and posterior fossa tumours. Somatosensory evoked potentials (SSEP) were monitored in all patients, and brain stem auditory evoked potentials (BAEP) in five. While minor changes in BAEP and SSEP parameters were noted in most patients, significant changes occurred in five. Irreversible loss of BAEP in one patient was associated with complete hearing loss postoperatively. Marked, persistent alteration of both BAEP and SSEP was associated with postoperative brainstem dysfunction. No patient with stable BAEP and SSEP at the end of the procedure suffered additional neurological deficit. We conclude that intraoperative SEP monitoring may be valuable in minimizing neural injury during major neurosurgical procedures.