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[Securing the airway in children with the Morquio-Brailsford syndrome].

Mucopolysaccharidosis IVA (Morquio-Brailsford syndrome) results from an inborn deficiency of n-acetyl-galactosamine-6-sulphate sulphatase. Clinical features include skeletal deformities with hypoplasia or absence of the odontoid process of the axis. The resulting atlanto-axial subluxation compresses the spinal cord, resulting in cervical myelopathy. Without treatment, quadriplegia ensues sooner or later; consequently, surgical decompression and dorsal fusion of the cervical vertebrae is recommended, either prophylactically or therapeutically. Anaesthesiological management must focus on protection of the airway without compromising integrity of the cervical spinal cord; quadriplegia subsequent to positioning of the head under anaesthesia has been reported. We have performed fiberendoscopic nasotracheal intubation in a 23-month-old child presenting for neurosurgical treatment of cervical myelopathy resulting from Morquio-Brailsford syndrome. CASE REPORT. A 23-month-old girl (84 cm, 11 kg) with Morquio-Brailsford syndrome presented for surgical decompression and dorsal fusion of the cervical spine. Pre-anaesthetic examination revealed enamel defects, chronic bronchitis, and splenomegaly; the neck was immobilised with a collar. Radiological examinations (X-ray and NMR) revealed narrowing of the atlanto-occipital and atlanto-axial spaces (Fig. 1) and compression of the cervical spinal cord (Figs. 2 and 3). Pre-anaesthetic medication consisted of midazolam juice (4 mg). After establishing intravenous access, atropine (0.5 mg), midazolam (1 mg), and ketamine (10 mg) were administered. A 22 Fr nasopharyngeal airway (Wendl) was lubricated with local anaesthetic gel and introduced into the right nostril; oxygen was administered through a probe to the left nostril. The Wendl-airway was then removed, another 5 mg ketamine was administered, and a 3.5-mm flexible fiberendoscope--over which a 20 Fr armored tube was slipped--was introduced through the right nostril. With the child spontaneously breathing, the glottis was visualised and the fiberscope introduced into the trachea (Fig. 4); 1 mg midazolam and 35 mg ketamine was administered and the endotracheal tube was advanced through the nose into the trachea, utilizing the fiberscope as a guide. The distance between endotracheal tube and carina was assessed endoscopically, the fiberscope withdrawn, and the tube connected to the breathing system. Pulse oxymetric readings were 98% during induction of anaesthesia including endotracheal intubation. Anaesthesia was continued with enflurane, alfentanil, midazolam, and atracurium; 315 min after induction the trachea was extubated and the child discharged to the paediatric intensive care unit. The postsurgical course was uneventful, and the child resumed co-ordinated gait. DISCUSSION. Airway management in patients with mucopolysaccharidoses may be extremely difficult. Recommended methods such as blind nasal intubation are not feasible in small children. Anaesthetic management in children younger than 2 years with Morquio-Brailsford syndrome presenting for cervical spine surgery has not yet been described. Fiberoptically guided nasotracheal intubation is a means of airway management that does not require repositioning of the head and may be performed with the stabilising collar left in place (Fig. 4); preservation of cervical spinal cord integrity may hence be assumed. Analgosedation with ketamine and midazolam allows sufficient spontaneous breathing and--to some extent--maintenance of protective laryngeal reflexes. In conclusion, anaesthetic management of patients with Morquio-Brailsford syndrome is a challenge that is further increased by extending indications for surgical intervention to include infants. With respect to protecting the airway, fiberoptic nasotracheal intubation of the spontaneously breathing child is our method of choice.

Female↗

Synovial cyst at the C1-C2 junction and spondyloarthropathy.

A spinal synovial cyst is a rare extradural benign tumor generally located at the lumbar spine, arising at the facet joint capsule, and usually associated with degenerative changes. We describe a 64-year-old woman with a synovial cyst involving the quadrate ligament of the odontoid process, which caused neurologic signs. Her family history was positive for spondyloarthropathy. The radiologic investigations, preoperative differential diagnosis, and association of spondyloarthropathy with this rare benign foramen magnum tumor are of particular interest.

Cervical Vertebrae↗

Cervical spine involvement in rheumatoid arthritis: prevalence and relationship with overall disease severity.

Rheumatoid arthritis (RA) affects the cervical spine in 20-90% of patients in Western countries. We report the prevalence of cervical spine involvement in RA and its relationship with duration of disease, seropositivity, hand joint erosions and symptoms and signs suggestive of cervical spine involvement. 100 patients with RA criteria were included. Apart from clinical history and examination, study included X-rays of the cervical spine in AP, open mouth and lateral views and posteroanterior view of hands and rheumatoid factor estimation. All X-rays were read by a radiologist who was unaware of the clinical details. Cervical spine involvement was seen in 65% of patients. The commonest abnormality was erosions of the odontoid process (47%), followed by atlanto-axial dislocation and apophyseal joint involvement (24%). Only 5% of patients had abnormalities of spinous processes or vertebral bodies. Patients with abnormal cervical spine radiographs had higher prevalence of rheumatoid factor and erosions on hand radiographs. Severity of cervical spine changes was related to duration of disease (> 5 years). No correlation was seen between symptoms and radiological abnormalities except when neurological deficit was present. Patients with seropositivity, erosive disease and disease duration greater than five years should be screened for cervical spine disease.

Adolescent↗

[Integrated role of computerized tomography and magnetic resonance imaging in identifying the early changes in rheumatoid arthritis of the craniocervical junction].

Any cervical spine segment may be affected by rheumatoid arthritis, but destructive changes are most prominent at the craniocervical junction. Cervical involvement is a devastating complication of the disease, because of the risk of a range of neurological complications (paresthesia, cervical myelopathy, vertebro-basilar insufficiency), and even sudden death from medullary compression. However, the incidence of both cervical rheumatoid arthritis and its neurological complications are still debated, being respectively reported in 17-86% and 11-70% of the patients, according to the variability in neurological and radiologic classification systems adopted by the authors. To assess the incidence of cervical rheumatoid arthritis and the integrated role of different imaging techniques in its diagnosis, 38 consecutive patients (29 women and 9 men) with rheumatoid arthritis according to the American Rheumatism Association criteria were examined. The average age was 60 years (range: 27-70 years) with a mean disease duration of 6.6 years (range: 6 months-25 years). All the patients underwent conventional radiography of the cervical spine, unenhanced Computed Tomography (CT) of the craniocervical junction and unenhanced and Gadolinium-enhanced Magnetic Resonance Imaging (MRI) of the cervical spine. Cervical spine involvement was demonstrated in 25/38 (66%) patients 20 women and 5 men, with an average age of 57 years and a mean disease duration of 8.5 years. In 13 of them (mean disease duration: 12.7 years), the diagnosis was made with radiography which showed atlantoaxial and subaxial subluxations and/or erosions. Of the 12 patients with negative conventional radiography (mean disease duration: 2.5 years), 4 were identified with both CT and MRI (synovial pannus and erosions). 3 with MRI only (joint effusion/hypervascularized synovial pannus), and 5 exhibited questionable CT findings which were clarified only by MR demonstration of inflammatory tissue contiguous to suspicious irregularities of the cortical bone of the odontoid process. 52% (13/25) of cervical rheumatoid arthritis patients were identified with plain radiographs, 68% (17/25) with CT and 100% (25/25) with MRI. Our preliminary data show that a specific tool for the diagnosis is recommended even in the early disease phases since rheumatoid arthritis commonly affects the craniocervical junction. Studying the craniocervical region is clinically difficult, and diagnostic imaging assessment is essential. Conventional radiography allowed to detect more than half the patients with cervical rheumatoid arthritis, but only in advanced disease stages. On the contrary, MRI had the unique potential of direct and detailed synovial visualization, thus permitting the diagnosis of cervical involvement even in the early phases of the inflammatory process, when CT findings were still negative or questionable.

Adult↗

[A midline vertebral artery aneurysm operated via transoral transclival approach (author's transl)].

A detail of an unsuccessful trial of transoral transclival operation for an aneurysm arising from the left vertebral artery was reported. The patient was 66 years old male who had bronchial asthma and difficulty in phonation and swallowing. The angiograms showed that the aneurysm, 1.5X1.5X2.0 cm in size, was situated in the midline at the level of caudal one-third of the clivus. A transoral transclival operation was performed following preoperative tracheostomy and gastrostomy to improve his pulmonary and nutritional condition. A midline incision on the palate was followed by the removal of the posterior half of palatal bone. The upper part of incision on the retropharyngeal mucosa was placed approximately 1 cm off the midline to facilitate closure afterwords. A caudal 1/3 of the clivus, anterior arch of the atlas and a part of the odontoid process were removed. The aneurysm, fusiform in shape, was then collapsed by needle puncture after the left vertebral artery was trapped between the posterior inferior cerebellar artery and the vertebro-basilar junction. Closure of the dura with a fascial patch was incomplete due to an extensive incision and coagulation of the dura. Closure of the retropharyngeal mucosa around the orifice of the Eustachian tube was also incomplete in spite of the paramedian incision described above. Postoperative course was complicated by an frequent occurrence of the attack of bronchial asthma causing loss of gastic juice from the gastrostomy and resultant hypoproteinemia, although the recovery of lower cranial nerve palsy was good. There was no signs of infection until the 21st postoperative day when meningitis developed. The patient died in the 28th postoperative day. The importance of complete closure of the dura and retropharyngeal mucosa to prevent meningial infection was discussed. Since the mucosa around the orifice of Eustachian tube was extremely friable and the closure was almost impossible, the risk of meningial infection was considered to be high, especially when the intradural procedure was necessary through transoral high clivotomy.

Aged↗

Fractures and dislocations of the cervical spine in children.

Correct diagnosis of fractures and dislocations of the cervical spine in children requires an awareness of the pseudosubluxation and other normal variants noted in x-ray films of patients in this age group. Fractures of the odontoid process occur frequently and almost always can be treated by closed reduction and external fixation until union occurs. Fractures of the lower cervical spine are difficult to detect roentgenographically, and x-ray changes can belie the severity of soft tissue injury and cord trauma. Instability tends to persist in adolescent patients after cervical spine injury because of the combination of epiphyseal and posterior ligamentous disruption. Neoplastic, inflammatory, and congenital lesions render the cervical spine vulnerable to injury and can permit major damage to result from minor stress.

Adult↗

Variation in the posterior vertebral contour line at the level of C-2 on lateral cervical roentgenograms: a method for odontoid fracture detection.

As an aid to the assessment of alignment and lordosis, four contour lines can be drawn on the lateral radiograph of the cervical spine. One of these contour lines is the posterior vertebral contour line, in which a smooth, gentle curve, convex anteriorly, is formed by a line drawn along the posterior margins of the cervical vertebral bodies. It is unknown whether discontinuity in the posterior contour line at this level represents a pathologic process of the odontoid. We analyzed the posterior cortex of C-2 and the odontoid in 500 lateral cervical spine radiographs to determine the amount of step-off (deviation from the posterior contour line) seen in normal lateral cervical roentgenograms. Only 15% (n = 75) showed any step-off; none exceeded 3 mm. We recommend that patients presenting with a history of cervical spine trauma who have a step-off at the posterior contour line at the odontoid/C-2 level of > or =3 mm should have fine-cut tomography or multiplanar computed tomography scanning to further assess the odontoid process and rule out fracture.

Adolescent↗

Diagnostic value on signs of subluxation of cervical vertebrae with radiological examination.

OBJECTIVE: To investigate the relationship between radiographic signs of subluxation in the cervical vertebrae and their clinical diagnostic value. DESIGN: Controlled, clinical study. SETTING: Institute of Clinical Anatomy and Biomechanics and NanFang Hospital of the First Military Medical University, Guangzhou, China. SUBJECTS: Eighty-seven subjects with cervicodynia and 21 asymptomatic volunteers. INTERVENTIONS: Radiological signs of subluxation from anteroposterior, lateral, open-mouth and dynamic radiographs of the cervical vertebrae of the subjects were measured and analyzed. MAIN OUTCOME MEASURES: The right and left odontoid lateral mass interspace, divergence of the spinous processes, sign of double contour and position of odontoid process were studied. RESULTS: The bilateral odontoid lateral mass interspaces were asymmetrical in most cases, and the divergence of spinous processes, sign of double contour and position of odontoid process were also common. Cervical vertebrae C5, C4 and C6 showed no special variations. CONCLUSION: There was little evidence to support the contention that signs of subluxation in the cervical vertebrae are of diagnostic significance. Subluxation should be defined in two ways: as a purely roentgenological diagnosis and as a combination of roentgenological signs with clinical signs.

Adolescent↗

Quantitative three-dimensional anatomy of the subaxial cervical spine: implication for anterior spinal surgery.

Knowledge of the quantitative anatomy of the subaxial cervical vertebrae is essential to safely perform anterior cervical surgery and to ensure adequate decompression of neural structures. In spite of this, little has been published in the neurosurgical literature regarding the spatial relationship of the lower cervical vertebrae and the implications of this anatomy for anterior cervical surgery. We report the three-dimensional analysis of the mid- and lower cervical spine in 10 cadaver specimens for 50 disarticulated vertebrae and discuss the relevance of this analysis to surgery in this region. Measurements were made using real-time video analysis of images transferred from a Zeiss microscope equipped with an image splitter and a Sony charge-coupled device camera. Images were then transferred to an IBM personal computer-based image analysis system. Analysis of variance was used to test for significant differences among the C3-C7 vertebral measurements. Important relationships of the vertebral artery to the anteroposterior diameter of the vertebral bodies and its variations from C3 to C7 are discussed. The vertebral artery migrates posteriorly to anteriorly from C3 to C6 and posteriorly again at C7; the implications of these variations are discussed for decompression of the neural foramen. Another finding showing that the inter-Luschka distance increases from C3 to C7 is important for adequate lateral decompression in anterior cervical spinal surgery. The pedicle to the Luschka joint was measured at the different levels; the pedicle is lateral to the Luschka joint from C3 to C6 and medial to the joint at C7. This variation explains the lack of root decompression at some cervical levels, even when decompression extends to the Luschka joint bilaterally. We also report the measurements of the vertebral bodies and the spinal canal and compare the results with other published data. We think these measurements provide guidelines for operating on the anterior cervical spine, facilitate adequate decompression of the spinal cord and neural foramen, and increase the margin of safety of the surgeon.

Anthropometry↗

Os odontoideum associated with hypertrophic ossiculum terminale. Case report.

The authors report on the case of a 20-year-old man who presented with a transient tetraparesis. Neuroimaging studies demonstrated atlantoaxial dislocation and ventral compression of the rostral spinal cord caused by a quite rare association of os odontoideum and hypertrophic ossiculum terminale. The patient underwent removal of two free ossicula via a transoral approach and posterior fusion in which an autogenous bone graft was placed. The majority of cases of os odontoideum are believed to be an acquired form; however, controversy with regard to the congenital causes of os odontoideum remains. One hypothesis is that os odontoideum results from the failure of fusion and the hypertrophy of the proatlas, although considerable confusion surrounds this hypothesis because definitive classification of os odontoideum-to differentiate between similar anomalies-has not been established. This rare coincidence in the current case supports the belief that os odontoideum has a different embryological origin from ossiculum terminale, which is thought to be a proatlantal remnant.

Abnormalities, Multiple↗

[Post-traumatic os odontoideum].

This is a report about a 20-month-old child with acquired os odontoideum caused by a fall. Diagnosis of atlanto-axial instability was eventually made 29 months later after repeated trauma and transitory tetraparesis. Dorsal C1/2 fusion with an autogenic rib graft and plaster fixation for 8 weeks failed; an autogenic iliac bone graft plus external fixation for 12 weeks finally resulted in solid fusion.

Aged↗

The ISG viewing wand: an application to atlanto-axial cervical surgery using the Le Fort I maxillary osteotomy.

Surgical access to the clivus and upper cervical spine may be facilitated by a number of approaches. The Le Fort I maxillary osteotomy has been described to give improved access to the skull base for removal of tumours and treating vertebrobasilar aneurysms. We describe a case in which the combination of a particularly high translocation of the body of C2 and poor mouth opening had precluded a standard transoral approach by restricting access to the operative field. Anterior decompression of the body of C2 was therefore performed via a maxillary down-fracture with the aid of an interactive image guidance system, the ISG Viewing Wand. The ISG Viewing Wand is a new intra-operative 3 dimensional (3D) image guidance system which has now been used in over three hundred neurosurgical cases at Frenchay Hospital, Bristol. We briefly discuss the principles of the viewing wand and describe its unique application providing anatomical navigation in upper cervical spine surgery.

Aged↗

Reliability and reproducibility of dens fracture classification with use of plain radiography and reformatted computer-aided tomography.

BACKGROUND: The classification system of dens fractures by Anderson and D'Alonzo has been widely used in clinical studies. Of the three types of fractures, Type II and Type III are of particular importance because the distinction between them may affect treatment decisions. The purposes of this study were to assess whether this classification is reliable and reproducible and to determine whether computed tomography can improve its reliability and reproducibility. METHODS: Plain radiographs and spiral computed tomography images of dens fractures in eleven patients were assessed, and the fractures were assigned a classification of Type II or Type III at two readings, separated by six months, by two spine surgeons and three neuroradiologists. Kappa coefficients of agreement between the raters as well as the reproducibility of the classifications made by the individual raters were calculated independently for the fracture classifications based on the plain radiographs and those based on the reformatted computed tomography scans. RESULTS: The kappa coefficient for classifications based on plain radiographs was 0.30 and 0.25 (fair agreement) at the first and second readings, respectively. For classifications based on computed tomography scans, the corresponding kappa coefficients were 0.46 (moderate agreement) and 0.67 (substantial agreement). The kappa coefficients for intrarater reliability among the five raters averaged 0.56 (moderate agreement) when computed tomography scans were used and 0.28 (fair agreement) when plain radiographs were used. CONCLUSIONS: Substantial variation with regard to the classification of dens fractures was found within our group of raters. Greater agreement occurred when reformatted computed tomography scans rather than plain radiographs were used as the basis for classification. When classifying dens fractures according to the system of Anderson and D'Alonzo, one should consider using reformatted computed tomography scans and reaching a consensus with multiple raters.

Adolescent↗

Treatment of traumatic atlanto-occipital dislocation in chronic phase.

We report the case of 27-year-old woman who presented with mild neurological deficits with significant anterior dislocation of the atlanto-occipital junction in a chronic phase after initial conservative treatment in another hospital. The importance of early diagnosis and treatment for atlanto-occipital dislocation is emphasized. The dislocation could not be reduced sufficiently either by halo ring cervical traction or surgical procedure 5 months after the accident. Therefore, transoral odontoidectomy for decompression of the medulla, together with the posterior occipitocervical fusion with a titanium loop brace was performed. The patient's symptoms disappeared completely within a few months after the operation. Magnetic resonance imaging findings suggesting soft tissue damage is the key to an early diagnosis and subsequent stabilization of traumatic atlanto-occipital dislocation in the early phase. Transoral decompressive odontoidectomy combined with posterior fusion may be considered for the treatment of irreducible atlanto-occipital dislocation in a chronic phase.

Adult↗

[Subdental synchondrosis. Computed tomographic and histologic investigation on morphological aspects of fracture at the base of the dens in 36 human axis specimens].

BACKGROUND: During development of the axis, four different ossification centers are formed. The two cranial ossification centers are demarcated from the ossification center of the vertebral corpus by a subdental synchondrosis. During further development the subdental synchondrosis--which is thought to close spontaneously--might not close completely, which leads to the necessity for differentiating synchondrotic remnants from a fracture at the base of the dens (type II according to Anderson and D'Alonzo). RESULTS: To characterize the architecture of the axis with particular attention to the subdental synchondrosis, the axis was harvested from 36 age- and gender-matched patients covering the human aging process from adolescence to senescence. In all specimens bone mineral density (BMD) was measured by peripheral quantitative computed tomography (pQCT). Morphological analysis after undecalcified processing of all specimens revealed a persistency of the subdental synchondrosis in 87% of all patients. Histological characterization of the subdental synchondrosis showed a cartilaginous structure interspersed with focal mineralization. Furthermore, static histomorphometric analysis revealed that trabecular bone volume and cortical thickness were significantly reduced within the base of the axis as compared to the dens and the corpus, respectively. CONCLUSION: Taken together, these results provide evidence that the base of the axis is a structurally distinct region. Besides well-recognized biomechanical aspects, these results suggest that the structure of the base of the axis might contribute to the occurrence of fractures of the axis and offer an additional explanation for the observation of nonunion after type II dens fractures.

Adolescent↗