Transtubular Transoral Approach for Irreducible Ventral Craniovertebral Junction Compressive Pathologies: Surgical Technique and Outcome

@#Introduction: To investigate the use of a tubular retractor to provide access to the craniovertebral junction (CVJ) sparing the soft palate with the aim of reducing complications associated with traditional transoral approach but yet allowing adequate decompression of the CVJ. Materials and methods: Twelve consecutive patients with severe myelopathy (JOA-score less than 11) from ventral CVJ compression were operated between 2014-2020 using a tubular retractor assisted transoral decompression. Results: All patients improved neurologically statistically (p=0.02). There were no posterior pharynx wound infections or rhinolalia. There was one case with incomplete removal of the lateral wall of odontoid and one incidental durotomy. Conclusions: A Tubular retractor provides adequate access for decompression of the ventral compression of CVJ. As the tubular retractor pushed away the uvula, soft palate and pillars of the tonsils as it docked on the posterior pharyngeal wall, the traditional complications associated with traditional transoral procedures is completely avoided.

Research Progress on the Application of Goel Technique in Craniovertebral Junction Anomalies / 中国医学科学院学报

Craniovertebral junction anomalies are a group of diseases characterized by the pathological changes of occipital bone,atlantoaxial bone,cerebellar tonsil,surrounding soft tissue,and nervous system,which are caused by a variety of factors.Chiari malformation is a common type of craniovertebral junction anomalies,the conventional surgical therapy of which is posterior fossa decompression.Currently,scholars represented by Goel have proposed a new theory on the classification,pathogenesis,and treatment of Chiari malformation based on posterior atlantoaxial fixation (Goel technique).This article introduces the progress in Goel technique,aiming to provide reference for the clinical work.

Congenital atlanto-occipital fusion and its effect on the myodural bridge: a case report utilizing the P45 plastination technique / Fusión atlanto-occipital congénita y su efecto sobre el puente miodural: reporte de un caso utilizando la técnica de plastinación P45

SUMMARY: The atlanto-occipital joint is composed of the superior fossa of the lateral masses of the atlas (C1) and the occipital condyles. Congenital Atlanto-occipital fusion (AOF) involves the osseous union of the base of the occiput (C0) and the atlas (C1). AOF or atlas occipitalization/assimilation represents a craniovertebral junction malformation (CVJM) which can be accompanied by other cranial or spinal malformations. AOF may be asymptomatic or patients may experience symptoms from neural compression as well as limited neck movement. The myodural bridge (MDB) complex is a dense fibrous structure that connects the suboccipital muscular and its related facia to the cervical spinal dura mater, passing through both the posterior atlanto-occipital and atlanto-axial interspaces. It is not known if atlas occipitilization can induce structural changes in the MDB complex and its associated suboccipital musculature. The suboccipital region of a cadaveric head and neck specimen from an 87-year-old Chinese male having a congenital AOF malformation with resultant changes to the MDB complex was observed. After being treated with the P45 plastination method, multiple slices obtained from the cadaveric head and neck specimen were examined with special attention paid to the suboccipital region and the CVJM. Congenital atlanto-occipital fusion malformations are defined as partial or complete fusion of the base of the occiput (C0) with the atlas (C1). In the present case of CVJM, unilateral fusion of the left occipital condyle with the left lateral mass of C1 was observed, as well as posterior central fusion of the posterior margin of the foramen magnum with the posterior arch of C1. Also noted was a unilateral variation of the course of the vertebral artery due to the narrowed posterior atlanto-occipital interspace. Surprisingly, complete agenesis of the rectus capitis posterior minor (RCPmi) and the obliques capitis superior (OCS) muscles was also observed in the plastinated slices. Interestingly, the MDB, which normally originates in part from the RCPmi muscle, was observed to originate from a superior bifurcation within an aspect of the nuchal ligament. Therefore, the observed changes involving the MDB complex appear to be an effective compensation to the suboccipital malformations.

RESUMEN: La articulación atlanto-occipital está compuesta por las caras articulares superiores de las masas laterales del atlas (C1) y los cóndilos occipitales. La fusión atlanto-occipital congénita (FAO) implica la unión ósea de la base del occipucio (C0) y el atlas (C1). La FAO u occipitalización/asimilación del atlas representa una malformación de la unión craneovertebral (MUCV) que puede presentar otras malformaciones craneales o espinales. La FAO puede ser asintomática o los pacientes pueden experimentar síntomas de compresión neural así como movimiento limitado del cuello. El complejo del puente miodural (PMD) es una estructura fibrosa densa que conecta el músculo suboccipital y su fascia relacionada con la duramadre espinal cervical, pasando a través de los espacios intermedios atlanto-occipital posterior y atlanto-axial. No se sabe si la occipitilización del atlas puede inducir cambios estructurales en el complejo PMD y en la musculatura suboccipital. Se observó en la región suboccipital de un espécimen cadavérico, cabeza y cuello de un varón chino de 87 años con una malformación congénita de FAO con los cambios resultantes en el complejo PMD. Se examinaron múltiples cortes obtenidos de la muestra de cabeza y cuello después de ser tratados con el método de plastinación P45, con especial atención a la región suboccipital y la MUCV. Las malformaciones congénitas por fusión atlanto-occipital se definen como la fusión parcial o completa de la base del occipucio (C0) con el atlas (C1). En el presente caso de MUCV se observó la fusión unilateral del cóndilo occipital izquierdo con la masa lateral izquierda de C1, así como fusión posterior central del margen posterior del foramen magnum con el arco posterior de C1. También se observó una variación unilateral del curso de la arteria vertebral por el estrechamiento del espacio interatlanto-occipital posterior. Se observó además agenesia completa de los músculos Rectus capitis posterior minor (RCPmi) y oblicuos capitis superior (OCS) en los cortes plastinados. Curiosamente, se observó que el MDB, que normalmente se origina en parte del músculo RCPmi, se origina en una bifurcación superior dentro de un aspecto del ligamento nucal. Por lo tanto, los cambios observados en el complejo PMD parecen ser una compensación de las malformaciones suboccipitales.

Feasibility of full-endoscopic posterolateral odontoidectomy / 西安交通大学学报(医学版)

【Objective】 To investigate the feasibility of full-endoscopic posterolateral odontoidectomy through morphological analysis and cadaver specimen surgery. 【Methods】 We collected the DICOM data of 20 normal cervical CT patients （10 males and 10 females） from the PACS Image Library of our hospital. The Mimics software was used for cervical CT reconstruction and anatomical measurements were made to measure the maximum sagittal diameter， coronal diameter and height of the odontoid process. The C1 lateral mass could provide the maximum working height and width of endoscopic operation with a diameter of 7 mm， as well as the angle between the anchor point of C1 lateral mass and the notch on both sides of the odontoid process. The feasibility of endoscopic surgery was analyzed based on the measured data. The fresh frozen corpse was used for the operation in prone position under the guidance of C-arm. Kirschner wire was anchored at the midpoint of the lower surface of the C1 lateral mass. Part of the C1 lateral mass was removed by the grinding drill and endoscopic tools， and then the odontoid process and adjacent ligaments were removed. 【Results】 The maximum sagittal diameter， coronal diameter and height of the odontoid process were （11.73±0.74）mm， （10.97±0.71）mm and （14.51±0.91）mm， respectively. The working height and width of the C1 lateral mass were （13.53±0.57）mm and （10.00±1.27）mm， respectively. The angle between the anchor point and the double-edge notch of the odontoid process was （28.3±3.1）°， with no statistical difference between the male and female patients （P>0.05）. All the measurements met the requirements of 7 mm endoscopic implantation and surgical operation， and the space for swing could be provided for complete or partial removal of the odontoid process to meet the requirements of ventral spinal decompression. In cadaver surgery， a fully endoscopic posterolateral approach enabled complete removal of the odontoid process by grinding part of the C1 lateral mass. Postoperative cervical CT confirmed that the odontoid process had been completely resected， and there were no signs of dural sac or vertebral artery injury. 【Conclusion】 The odontoid process can be completely resected through a posterolateral endoscopic approach via the lateral mass approach of C1， providing a new surgical method for clinical odontoidectomy to decompress the spinal cord in craniovertebral junction.

Beethoven´s illnesses and a craniovertebral junction variant? / As doenças de Beethoven e variante da junção craniovertebral?

Ludwig van Beethoven, the great composer, born 250 years ago, had several health problems and a progressive hearing loss. Gastrointestinal symptoms prevailed among his physical complaints, but there were also frequent headaches, eye pain, and polyarthralgia. Likewise, there are many reports about his alcohol intake and frequent walks. There were also peculiar behavioral and awkward physical aspects of the famous composer. All may take part as a determinant for the communicative aspects of his music. Spite Beethoven's corporal structure could be considered just a developmental variant, it can also be congenitally related to many bone-nervous abnormalities such as craniovertebral junction malformation with interference in the Genius' health. In reality, it is almost impossible to cover Beethoven's entire health problem with just one underlying disease. Most likely, he had comorbidities, one of which, although not fatal, was that related to abnormalities in the development of the skull and cervical spine worsened by a baseline autoimmune disorders that injured joints, and maybe even the VIII cranial nerve and inner ear.

Ludwig van Beethoven, o grande compositor, nascido há 250 anos, teve vários problemas de saúde e uma perda auditiva progressiva. Os sintomas gastrointestinais prevaleceram entre suas queixas físicas, mas também houve frequentes episódios de cefaleia, dores nos olhos e poliartralgia. Da mesma forma, há muitos relatos sobre sua ingestão de álcool e caminhadas frequentes. Havia também aspectos físicos peculiares e estranhos do famoso compositor. Todos podem tomar parte como um determinante para os aspectos comunicativos de sua música. Apesar da estrutura corporal de Beethoven poder ser considerada apenas uma variante de desenvolvimento, pode também estar relacionada a algumas anormalidades ósseo- neural, tais como a malformação da junção craniovertebral com interferência na saúde do Gênio. Na realidade, é quase impossível cobrir todo o problema de saúde de Beethoven com apenas uma doença subjacente. Muito provavelmente, ele tinha comorbidades, uma das quais, embora não fatal, era aquela relacionada a anormalidades no desenvolvimento do crânio e da coluna cervical agravadas por uma desordem auto-imune de base que lesionava as articulações, e talvez até o VIII nervo craniano e o ouvido interno.

Craniometric parameters for the evaluation of platybasia and basilar invagination on magnetic resonance imaging: a reproducibility study / Parâmetros craniométricos para platibasia e invaginação basilar na ressonância magnética: estudo de reprodutibilidade

Abstract Objective: The present study aims to perform a reproducibility study of the clivus-canal angle (CCA), Welcker's basal angle (WBA), and the distance from the odontoid process to Chamberlain's line (DOCL) on magnetic resonance imaging (MRI). Materials and Methods: Two medical students and two radiologists respectively evaluated 100 and 50 consecutive MRI scans of adult skulls, selected randomly. Each examiner, working independently and blinded to the previous results, performed readings for each patient on two different occasions. Measurements were performed in T1-weighted sequences acquired in the midsagittal plane. The levels of intraobserver reproducibility and interobserver agreement were evaluated by calculating the intraclass correlation coefficients (ICCs) and the corresponding 95% confidence intervals. Results: The mean values obtained by the examiners were 150° for the CCA, 130° for the WBA, and 2.5 mm for the DOCL. The ICC for interobserver agreement was 0.980, 0.935, and 0.967, for the CCA, WBA, and DOCL, respectively, for the students, compared with 0.977, 0.941, and 0.982, respectively, for the radiologists, and 0.980, 0.992, and 0.990, respectively, for all of the examiners together. In the analysis of intraobserver agreement, the ICC ranged from 0.929 to 0.959 for the CCA, from 0.918 to 0.964 for the WBA, and from 0.918 to 0.981 for the DOCL. Conclusion: The measurement of the CCA, WBA, and DOCL appears to show excellent intraobserver reproducibility and interobserver agreement on MRI.

Resumo Objetivo: Realizar um estudo de reprodutibilidade do ângulo clivocanal (ACC), ângulo basal de Welcker (ABW) e distância do odontoide à linha de Chamberlain (DOLC) em ressonância magnética (RM). Materiais e Métodos: Quatro examinadores, dois graduandos de medicina e dois radiologistas, avaliaram, respectivamente, 100 e 50 indivíduos adultos submetidos a RM de crânio, consecutiva e aleatoriamente. Cada um realizou duas leituras para cada paciente em diferentes ocasiões, de forma cega e independente. As análises de concordância intraobservador e interobservador foram realizadas pelo coeficiente de correlação intraclasse (CCI), com intervalo de confiança de 95%. Resultados: As medidas médias, considerando todos os examinadores, foram: ACC = 150°, ABW = 130°, DOLC = 2,5 mm. A análise interobservador entre os estudantes revelou CCI de 0,980, 0,935 e 0,967 para ACC, ABW e DOLC, respectivamente, e para os radiologistas, CCI de 0,977, 0,941 e 0,982, respectivamente. A análise interobservador entre estudantes e radiologistas revelou CCI de 0,980, 0,992 e 0,990, respectivamente. Em relação à análise intraobservador, as medidas do ACC tiveram CCI variando entre 0,929 e 0,959, ABW entre 0,918 e 0,964 e DOLC entre 0,918 e 0,981. Conclusão: ACC, ABW e DOLC obtiveram excelentes reprodutibilidades intraobservador e interobservador na RM.

Observational outcome in surgery for Chiari malformation patients

Chiari malformation is the commonest anomaly of the craniovertebral junction involving both the skeletal as well as the neural structures. It is congenital anomaly of the hindbrain characterised by downward elongation of the brain stem and cerebellum into the cervical portion of spinal cord. Most common presenting symptoms was pain in the nape of neck with sub-occipital headache and weakness. If not intervened early in these cases they may progress to quadriparesis and respiratory failure. This study includes authors experience of 30 surgical corrections of Chiari malformation performed at civil hospital Ahmedabad from 2017 to 2019. The age and sex of the patient, the presence of syrinx, the type of surgical procedure and the clinical outcome were determined post-operatively and on follow up. Cerebro spinal fluid leak and collection were observed in patient who undergone duroplasty only with no leakage in patient undergone syringo-subarachnoid shunt. Overall, tingling/numbness had best improvement showed improvement in 13 out of 16 patients. Power showed improvement in 20 out of 27 patients and pain showed improvement in 18 patients. Wasting, clawing and cerebellar signs and bony deformity showed no improvement in any of the above procedures. Authors can conclude for Chiari malformation decompression with or without duroplasty with additional procedure with post-operative physiotherapy and analgesia is the suitable treatment.

An observation on risk of infection in treatment of craniovertebral junction disorders by transoral approach operation / 中国修复重建外科杂志

Objective: To study the changes of bacterial flora after a series of preoperative oral disinfection and the postoperative recovery of patients with craniovertebral junction disorders who were treated with transoral approach operations. And to provide a theoretical basis for the prevention of postoperative complications such as infection. Methods: The clinical data of 20 cases with craniovertebral junction disorders and treated with transoral approach operations between October 2009 and May 2010 were analyzed. There were 8 males and 12 females, aged 2-66 years (median, 34.5 years). According to the classification of American Spinal Injury Association (ASIA)，there were 4 cases of grade B, 8 of grade C, 6 of grade D, and 2 of grade E. The Japanese Orthopedic Association (JOA) score was 10.3±3.0. The mucosa samples of the posterior pharyngeal wall were sent for bacteria culture. These samples were collected by sterile cotton swabs at four crucial points including 3 days before operation/before gargling (T1), 3 days after continuous gargling by chlorhexidine acetate/after anesthesia intubation on the day of operation (T2), after intraoperative cleaning and washing of the mouth (T3), and after intraoperative iodophor immersion for 5-10 minutes (T4). The microflora was stained by means of smear and further counted after an investigation by microscope. The ASIA classification and the JOA scores were applied to evaluate the postoperative nerve function of the patients. A regular reexamination of cervical vertebra with X-ray film, CT, and MRI was conducted after operation to evaluate the reduction of atlantoaxial dislocation, internal fixation position, bone graft fusion, inflammatory lesion, and tumor resection in the craniovertebral junction. Results: After a series of oral disinfection, the mucosa of the posterior pharyngeal wall of all the patients was in a sterile state, which was considered as type Ⅰ incision. All these 20 patients were treated with successful operations, without any intraoperative injury in vertebral artery and spinal cord, or any postoperative complications such as plate loosening, incision infection, or intracranial infection. All the patients were followed up 3-23 months, with an average of 5.15 months. The symptoms such as neck pain, limb numbness and weakness, neural symptoms, etc. were improved to different degrees after operation. The JOA score was improved to 13.4±1.9 at 3 months after operation, showing significant difference when compared with preoperative score ( t=8.677, P=0.000); and the atlantoaxial joints had been fused. At last follow-up, the ASIA grades were improved when compared with those before operation. Conclusion: It is safe and effective to cut the posterior pharyngeal muscle layer and implant internal fixation by means of transoral approach in the treatment of craniovertebral junction disorders.

An application of posterior cervical and transoral approaches to treating primary malignant osseous tumors in craniovertebral junction / 中国修复重建外科杂志

Objective: To investigate the surgical method for primary malignant osseous tumors in the craniovertebral junction (CVJ) and its effectiveness. Methods: The clinical data of 7 patients with primary malignant osseous spinal tumors in CVJ, which collected between September 2010 and April 2019, were retrospectively analyzed. There were 5 males and 2 females, aged 23 to 75 years (median, 56 years). All patients were diagnosed as chordoma in 4 cases, plasmacytoma in 2 cases, and fibrosarcoma in 1 case. The disease duration ranged from 0.7 to 36.0 months, with an average of 12.2 months. Lesion location: 1 case of C 0, 1, 3 cases of C 2, 1 case of C 1, 2, 1 case of C 2, 3, and 1 case of C 0-2. Preoperative visual analogue scale (VAS) score was 6.7±2.1, the Japanese Orthopaedic Association (JOA) score was 15.6±2.4. According to American Society of Spinal Cord Injury (ASIA) grading system, there was 1 case of grade C, 1 case of grade D, and 5 cases of grade E. According to Enneking stage of spinal malignant tumor, there was 1 case of stage ⅠB, 2 cases of stage ⅡB, and 4 cases of stage Ⅲ. According to Weinstein-Boriani-Biagini (WBB) stage, there was 1 case of 5-8/A-D, 1 case of 4-9/A-D, 1 case of 6-7/B-D, 1 case of 6-7/A-D, 2 cases of 1-12/A-D, and 1 case of 3-10/A-D. All these patients were treated with tumor extended resection, bone graft fusion, and internal fixation via posterior cervical approach, as well as tumor (stage Ⅰ or stage Ⅱ) boundary resection via transoral or submandibular approach. Meanwhile, anterior reconstructive fusion was procedured with bone grafting Cage needed to place the internal fixation. Results: The operation time was 307-695 minutes (mean, 489.57 minutes), and the intraoperative blood loss was 400-2 000 mL (mean, 1 107.14 mL). There was no intraoperative injury in vertebral artery and spinal cord or any related postoperative complications, including incision infection, intracranial infection, and pulmonary infection. All the patients were followed up 3-57 months (mean, 21 months). Postoperative X-ray film and CT showed that the internal fixation screw was firm and in a satisfactory position, and the bone graft was fused at 3-6 months after operation. Symptoms such as neck pain, limb numbness, and fatigue relieved to different degrees after operation. At 3 months after operation, the VAS score improved to 1.7±0.8 ( t=7.638, P=0.000); while the JOA score improved to 16.1±1.5, but no significant difference was found when compared with preoperative score ( t=1.549, P=0.172). According to ASIA grading system, 1 patient with grade C had upgraded to grade D after operation, while the remaining patients had no change. There were 4 cases of recurrence after operation, in which those patients were with high malignancy of tumors before the first surgery. Their tumors also affected a wide range of slope or surrounding soft tissues and could not be completely removed. Among the 4 cases, 1 patient underwent transoral tumor removal operation again, while the other 3 cases gave up further treatment. There was no recurrence among the remaining 3 cases. Conclusion: Primary malignant osseous tumors in the CVJ can be completely exercised via means of trabsoral or submandibular approach. Meanwhile the anterior reconstruction can be achieved by placing special Cage specimen. These two methods together with postoperative adjuvant treatments such as radiotherapy and chemotherapy can improve the survival time of patients and reduce tumor recurrence.

Bilateral Accessory C1 and C2 Facet Joints; Clinical, Neuroradiological and Peroperative Findings in an Adult with Quadriparesis

Objectives Accessory C1 and C2 facet joints are very rare. Only few cases were reported in the literature.We report a case of bilateral accessory facets in an adult with special attention to clinical, neuroradiological, as well as peroperative findings. Case report A 37-year-old male presented with progressive quadriparesis. Radiology revealed bilateral posterior accessory C1 and C2 facet joints compressing the spinal cord with craniovertebral junction (CVJ) instability. Both accessory C1 and C2 facets with the posterior arch of the C1 were removed. Lateral mass screws and plates fixation at the C1 and C2 level, as well as fusion, were performed. Postoperatively, the patient recovered well. Conclusion In accessory C1 and C2 facet joints, when symptomatic, neuroradiological findings can guide to the proper diagnosis, to pathological understanding, and, ultimately, to management strategy.

Morphometric Study Of Dry Human Occipital Bone And Its Clinical Relevance

Background: Anomalies of craniovertebral junction (CVJ) are of interest both to an anatomist as well as to theclinicians because many of these deformities produce clinical symptoms. The stability of this CVJ dependslargely on the morphometric parameters of the occipital condyles (OCs). Most of the surgical approaches suchas, the lateral trans-jugular approach, trans-tubercular approach and transcondylar approach require resectionof the condyles.Materials and methods: The measurements of 30 occipital condyle length, width, height, Size and the anteriorand posterior intercondylar distances, Distance between the anterior tip of OC & Basion, Distance between theposterior tip of OC & Opisthion, Anterior intercondylar distance (AID), Posterior intercondylar distance (PID),non-metric parameters including Shape was done.Results: Mean length, width and height of the occipital condyle were found to be 23.2, 12.39 and 9.16 mm on theright and 23.43, 12.31 and 8.95 mm on the left respectively. The anterior and posterior intercondylar distanceswere 21.28 and 40.61 mm respectively.Conclusion: The occipital condyles are integral part of neck and base of the skull. In the present study an effortwas made to measure various parameters related to occipital condyle. The data may be used as a morphometricdata base for posterior and lateral approaches to the craniovertebral junction by neurosurgeons andorthopaedicians

Basilar invagination associated with chiari malformation type I: A literature review

Basilar invagination (BI) and Chiari malformation type I (CM-I) are very important anomalies that introduce instability and compression in the occipitocervical transition region and have complex clinical characteristics. These anomalies vary according to the affected structures. The present study revises current knowledge regarding the anatomy, anatomo-physiology, clinical manifestations, and radiological findings of these entities and the associated surgical treatment approaches. A bibliographic survey was performed through a search in the Medline, PubMed, SciELO, Science and LILACS databases. When associated, these craniovertebral malformations result in neurological deficits due to neural parenchyma compression; however, the presence of microtraumas due to repetitive lesions caused by the bulb and cervical marrow instability has been highlighted as a determinant dysfunction. Surgical treatment is controversial and has many technical variations. Surgery is also challenging due to the complex anatomical characteristics and biomechanics of this region. Nevertheless, advances have been achieved in our understanding of related mechanisms, and compression and atlantoaxial instability are considered key elements when selecting the surgical approach.

Comparison of Occipital Condyle Morphometry in Various Populations with Respect to Skull Base Surgery

Background: The craniovertebral junction is made up of the occiput, upper two cervical vertebrae. Occipital condyle is one the landmarks on the skull base. Morphometric values of these condyles in a specific population is to be known by surgeons to deal with pathologies affecting the cranial base without disturbing the neurovascular structures by doing appropriate condylectomy and to ensure occipito-cervical fusion in case of instability. Methods: The study was performed by comparing the morphometric values of occipital condyles with other populations (Greek, Turkish, Korean, Chinese, American, European and Indian). The data regarding the morphometric values of occipital condyles was taken from our previously published article with a sample of hundred occipital condyles of unsexed dry human skulls of unknown age and compared with the studies of other population. The measurements compared were the length, breadth and thickness of the occipital condyle, intercondylar distance in anterior, middle and posterior parts of the occipital condyles, the angle of the occipital condyle to the sagittal plane and coronal planes and shape of the occipital condyles. Results: Most of the morphometric values of OC in South Indian were lesser than the other populations like breadth, thickness,anterior intercondylar distance, posterior intercondylar distance, angle of the occipital condyle to the sagittal plane. Conclusion: This information has to borne in mind while performing surgical procedures like occipito-cervical screw fixation, condylar drilling in cranial base surgery in South Indian population.

Effect of occipitocervical fusion for treatment of craniovertebral junction deformity combined with atlantoaxial instability / 中国医师进修杂志

Objective To investigate the effect of occipitocervical fusion in patients with craniovertebral junction deformity combined with atlantoaxial instability. Methods The clinical data of 59 patients with craniovertebral junction deformity combined with atlantoaxial instability from March 2013 to June 2017 were retrospectively analyzed. The patients were treated with occipitocervical fusion. The atlantoaxial distance (ADI), distance between the odontoid and Chamberlain line and cervicomedullary angle (CMA) were used to evaluate atlantoaxial dislocation, vertical displacement and spinal cord compression, and the Japan Orthopedic Association (JOA) score was used to evaluate the effect before operation and 7 days after operation. Results The operation time was 109 to 214 (148.5 ± 20.1) min, the transoperative bleeding was 55 to 210 (122.0 ± 16.7) ml, and no injury of spinal cord nerve and vertebral artery occurred during operation. The CMA and JOA score 7 d after operation were significantly higher than that before operation: (153.8 ± 5.4)° vs. (131.2 ± 7.1) ° and (12.7 ± 1.8) scores vs. (10.6 ± 1.4) scores, and the ADI and distance between the odontoid and Chamberlain line 7 d after operation were significantly lower than that before operation: (2.9 ± 0.7) mm vs. (8.3 ± 2.7) mm and (3.2 ± 1.4) mm vs. (8.2 ± 2.3) mm, and there were statistical difference (P＜0.05). One case (1.7%, 1/59) died of massive brainstem infarction 1 d after operation; 2 patients (3.4%, 2/59) had undergone a revision operation due to fusion failure 3 months after operation; other 56 patients in reduction, internal fixation and bone graft fusion. The patients were followed up for 6 to 38 (15.9 ± 7.2) months, and the symptom relief was in 56 cases. The rate of symptom relief was 94.9% (56/59). The JOA score at last follow-up was significantly higher than that before operation: (13.3 ± 1.8) scores vs. (10.6 ± 1.4) scores, and there was statistical difference (P＜0.05). Conclusions The occipitocervical fusion can effectively relieve spinal cord compression and atlantoaxial instability in patients with craniovertebral junction deformity combined with atlantoaxial instability.

Quantification of Pediatric Cervical Spine Growth at the Cranio-Vertebral Junction

OBJECTIVE: The purpose of this study was to investigate morphological change at the craniovertebral junction (CVJ) region using computed tomography. METHODS: A total of 238 patients were included in this study, and mean age was 47.8+/-21.3 months. Spinal canal diameter, Power's ratio, McRae line, antero-posterior C1 ring height, atlantoaxial joint space, C2 growth, epidural space from the dens (M-PB-C2) and longitudinal distance (basion to C2 lower margin, B-C2) were measured. The mean value of each parameter was assessed for individual age groups. The cohorts were then divided into three larger age groups : infancy (I) ( or = years). RESULTS: Spinal canal diameter increased with age; however, this value did not increase with statistical significance after VE age. A significant age-related difference was found for all C2 body and odontoid parameters (p<0.05). Mean McRae line was 8.5, 8, and 7.5 mm in the I, VE, and E groups, respectively. The M-PB-C2 line showed up-and-down dynamic change during early pediatric periods. CONCLUSION: Expansion of the spinal canal was restricted to the very early childhood period (less than 5 years) in the CVJ region; however, the C2 body and odontoid process increased continuously with age. The above results induced a dynamic change in the M-PB-C2 line. Although C2 longitudinal growth continued with age, the McRae line showed relatively little change.

Treatment of Syringomyelia due to Chiari Type I Malformation with Syringo-Subarachnoid-Peritoneal Shunt

Chiari type I malformation is a tonsillar herniation more than 3 mm from the level of foramen magnum, with or without concurrent syringomyelia. Different surgical treatments have been developed for syringomyelia secondary to Chiari's malformations: craniovertebral decompression with or without plugging of the obex, syringo-subarachnoid, syringo-peritoneal, and theco-peritoneal shunt placement. Shunt placement procedures are useful for neurologically symptomatic large-sized syrinx. In this paper, authors define the first successful treatment of a patient with syringomyelia due to Chiari type I malformation using a pre-defined new technique of syringo-subarachnoid-peritoneal shunt with T-tube system.

Basilar imagination : a rare cause of "top of basilar artery" syndrome.

"Top of Basilar Artery" Syndrome as the presentation of CVJ anomalies is extremely rare. The association between skeletal CVJ anomalies and vertebro-basilar insufficiency (VBI) is recognised and angiographic abnormalities of the vertebro-basilar arteries and their branches have been reported. Atlanto-axial dislocation (AAD) is the commonest skeletal cranio-vertebral junction (CVJ) anomaly in India, followed by occipitalisation of atlas and basilar invagination. They usually present with a progressive neurological deficit (70 - 94% cases) implicating the high cervical cord, lower brainstem, and cranial nerves. We report one such case with the even more rare presentation of "Top of Basilar Artery" Syndrome as the initial presentation of basilar invagination.

Traumatic Atlanto-occipital Dislocation (AOD)

OBJECTIVE: Traumatic atlanto-occipital dislocation (AOD) results from high energy trauma and is an uncommon and usually fatal injury due to an injury to the cervicomedullary junction. Recently, improved prehospital management, early diagnosis and effective treatment led to increasing reports of survival. This study of patients with AOD initial imaging modalities recognizes the clinical features and diagnostic considerations for a quick diagnosis. METHODS: In this article, five survived adult patients with traumatic AOD are presented and retrospectively reviewed. Diagnosis was made by lateral cervical spine x-ray, cervical computed tomography (CT), or magnetic resonance imaging(MRI). Treatment consisted of early immobilization, respiratory support, and subsequent occipitocervical fusion. RESULTS: Four patients were male and the other one was female. Three were diagnosed early and the others were delayed in confirmations. One was type I AOD and four were type II AOD. All patients were applied occipitocervical fusion. Two cases were worse; neurological states and the other three that showed no change. Lateral X-ray film of all patients in the prevertebral soft tissue swelling at the C2 level was noted. The mean thickness of prevertebral soft tissue C2 level was 17.88 mm(15.18 to 20.17mm). Two were in the normal range of dens-basion index(DBI), three showed abnormalities, and Power's ratio was abnormal in 3 patients. CONCLUSION: As for damages caused by a strong external force in patients with severe prevertebral soft tissue swelling at C2 level abnormaly, the doctor determines whether more should be carefully AOD and considers 3D CT or MRI to confirm AOD in these patients.

Traumatic Atlanto-occipital Dislocation (AOD)

OBJECTIVE: Traumatic atlanto-occipital dislocation (AOD) results from high energy trauma and is an uncommon and usually fatal injury due to an injury to the cervicomedullary junction. Recently, improved prehospital management, early diagnosis and effective treatment led to increasing reports of survival. This study of patients with AOD initial imaging modalities recognizes the clinical features and diagnostic considerations for a quick diagnosis. METHODS: In this article, five survived adult patients with traumatic AOD are presented and retrospectively reviewed. Diagnosis was made by lateral cervical spine x-ray, cervical computed tomography (CT), or magnetic resonance imaging(MRI). Treatment consisted of early immobilization, respiratory support, and subsequent occipitocervical fusion. RESULTS: Four patients were male and the other one was female. Three were diagnosed early and the others were delayed in confirmations. One was type I AOD and four were type II AOD. All patients were applied occipitocervical fusion. Two cases were worse; neurological states and the other three that showed no change. Lateral X-ray film of all patients in the prevertebral soft tissue swelling at the C2 level was noted. The mean thickness of prevertebral soft tissue C2 level was 17.88 mm(15.18 to 20.17mm). Two were in the normal range of dens-basion index(DBI), three showed abnormalities, and Power's ratio was abnormal in 3 patients. CONCLUSION: As for damages caused by a strong external force in patients with severe prevertebral soft tissue swelling at C2 level abnormaly, the doctor determines whether more should be carefully AOD and considers 3D CT or MRI to confirm AOD in these patients.

Robot-Assisted Transoral Odontoidectomy : Experiment in New Minimally Invasive Technology, a Cadaveric Study

OBJECTIVE: In the field of spinal surgery, a few laboratory results or clinical cases about robotic spinal surgery have been reported. In vivo trials and development of related surgical instruments for spinal surgery are required before its clinical application. We investigated the use of the da Vinci(R) Surgical System in spinal surgery at the craniovertebral junction in a human cadaver to demonstrate the efficacy and pitfalls of robotic surgery. METHODS: Dissection of pharyngeal wall to the exposure of C1 and odontoid process was performed with full robotic procedure. Although assistance of another surgeon was necessary for drilling and removal of odontoid process due to the lack of appropriate end-effectors, successful robotic procedures for dural sutures and exposing spinal cord proved its safety and dexterity. RESULTS: Robot-assisted odontoidectomy was successfully performed in a human cadaver using the da Vinci(R) Surgical System with few robotic arm collisions and minimal soft tissue damages. Da Vinci(R) Surgical System manifested more dexterous movement than human hands in the deep and narrow oral cavity. Furthermore, sutures with robotic procedure in the oral cavity demonstrated the advantage over conventional procedure. CONCLUSION: Presenting cadaveric study proved the probability of robot-assisted transoral approach. However, the development of robotic instruments specific to spinal surgery must first precede its clinical application.