Atlantoaxial Region Research Articles

One-year multidrug treatment for tuberculosis of the cervical spine in children.

To review the clinical and radiological features and treatment outcome in 22 children who underwent one-year antitubercular multidrug treatment for tuberculosis of the cervical spine. Records of 13 boys and 9 girls aged 2 to 12 (mean, 9.1) years who underwent one-year antitubercular multidrug treatment for tuberculosis of the cervical spine were reviewed. Tuberculosis involved the atlantoaxial region (C1-C2) in 7 patients, mid-cervical region (C3-C7) in 8, cervicodorsal region (C6-T3) in 3, contiguous multilevels in 2, and non-contiguous multifocal areas in 2. The mean number of vertebrae involved was 2.8 (range, 1-8). The mean symptom duration was 2.5 (range, 0.25-6) months. Three patients had neurological deficits. Antitubercular multidrug treatment included an intensive phase for 2 months and a continuation phase for 10 months, using isoniazid, rifampicin, pyrazinamide, and ethambutol. At a mean of 2.25 (range, 0.5-5) years after treatment, no patient had recurrence, pain, or dynamic instability. Full range of movement was achieved after a mean of 2.7 (range, 1-4) months in all but 3 patients. In the 3 patients with neurological deficits, recovery was achieved after a mean of 8 (range, 5-14) weeks. Soft tissue swelling resolved after a mean of 11 (range, 8-12) weeks. Remineralisation of vertebrae occurred after a mean of 2 (range, 2-6) months. Spontaneous vertebral fusion occurred in only 6 of 22 patients after a mean of 36 (range, 18-72) months. Three patients developed kyphotic deformity. Antitubercular multidrug treatment is a viable option for children with tuberculosis of the cervical spine, even in the presence of neurological deficits. Development of deformity is not common; interbody fusion is usually delayed. Patients with contiguous multilevel involvement with vertebral erosion or collapse should be closely monitored for development of late deformity.

Treatment of C2 Vertebral Body and Dens Tumors with Intraoperative Transoral or Transpedicular Vertebroplasty and Occipitocervical Posterior Fixation

Introduction Metastatic spinal tumors of the atlantoaxial region are quite uncommon thus surgical treatment is difficult and challenging procedure. The origin of these metastatic tumors are mainly breast, lung, and prostate neoplasms, or part of hematopoietic disorders such as myeloma multiplex, lymphoma. Clinical management of the C2 metastatic lesions includes open surgery, radiotherapy, vertebroplasty, and external immobilization. The aim of our study was to evaluate the safety and efficacy of simultaneous intraoperative transoral or transpedicular vertebroplasty combined with posterior fixation in case of C2 vertebral metastatic disease. Patients and Methods We enrolled five patients with osteolytic C2 vertebral metastasis. The origin of the metastatic tumors was breast cancer in two cases, lung cancer in two cases, and multiple myeloma in one case. In three cases, we made purely posterior approach by dorsal open C2 biopsy and transpedicular vertebroplasty followed by posterior occipitocervical fixation. In the other two cases, patients underwent transoral C2 biopsy and vertebroplasty and dorsal occipitocervical fixation in the same session. The patients were followed with regular fluoroscopy, MRI, CT scans, and neurological examinations immediately after the operation and thereafter at 6 months. The HALO fixation device was removed after the first postoperative CT examination. Results During our 8 to 19 months (average 13 months) follow-up period, we had no surgical or neurological complications with respect to this combined approach. The incidence of postoperative cervical pain was lower, compared with the preoperative pain. Preoperative VAS was 7 (6–8), while postoperative VAS was 3.5 (2–5). On postoperative neurological and radiological follow-up, no surgical or neurological complications developed with respect to this combined approach of the atlantoaxial region of the spine. The average volume of PMMA injected was 4 mL. We filled more than 60% of each patient's C2 vertebral body and dens. Conclusion In this small series of simultaneous intraoperative transoral or transpedicular vertebroplasty and dorsal occipitocervical fixation proved to be a safe and effective treatment for patients with osteolytic C2 metastatic tumors. These techniques may provide excellent pain relief and improvements in quality of life. The true value of these combined techniques should be evaluated in larger series.

The treatment of atlantoaxial instability with posterior hybrid fixation techniques

Objective To evaluate the indications, safety and clinical outcomes of hybrid internal fixation techniques in the treatment of atlantoaxial instability. Methods From June 2010 to June 2013, a retrospective study was done on 19 patients (7 males and 12 females, with age range of 15 to 57 years, mean 40±13 years) with atlantoaxial instability who had undergone the treatments of atlantoaxial fusion operations with hybrid fixation techniques. All of 19 patients suffered from neck pain or limitations of cervical motion. Among them, 5 cases presented only the neck pain while 14 cases combined with spinal cord compression systems, including different degrees of sensory and motor disorders and increased reflex. The atlantoodontoid interval was larger than 3 mm in 8/19 cases with an average of 6.4±3.0 mm (3-10 mm). The distance from lateral mass of atlas burst fracture was 7-9 mm (mean, 7.7±0.9). CT scan was used to evaluate the height of the lateral arch above bilateral axial vertebral arteries, with 4 cases < 4 mm unilaterally. The atlantoaxial fusion was achieved using hybrid fixation techniques, including transarticular screw, C1 lateral mass screw, C2 pedicle screw, C2 translaminar screw and C1 laminar hook. The neck pain that all patients suffered was measured by Visual analogue scale (VAS), and the degree of cervical spinal cord injury of 14 patients who had neural symptoms and dysfunction was evaluated by Japanese Orthopedic Association score (JOA) and the rate of the improved JOA score (RIS). Cervical X-ray and CT scan after operation were used to observe the internal fixations and bone fusion during the follow-up. Results All the 19 patients got 12 to 24 months' follow-up, 15.3±4.2 months at average. In 3 months follow-up time, all patients got relief from the neck pain, the VAS of neck pain decreased to 1.2±0.97 after 3 months and to 0.63±0.76 at last follow-up postoperatively, comparing to 4.5±1.54 preoperatively. The JOA score increased to 14.5±1.8 after 3 months and to 16.1±1.2 postoperatively, comparing to 12.2±1.9 preoperatively. In 12 to 24 months (15.3±4.2 on average) follow-up there was no failure of internal fixations, pseudarthrosis or instability. No spinal cord injury or vascular complications occurred. Conclusion The evaluation about the anatomical structure of atlantoaxial region by radiographic examinations is essential to the appropriate options of internal fixations. The individual surgical procedures usinghybrid fixation techniques are safe and effective. Key words: Atlanto-axial joint; Joint instability; Spinal fusion; Treatment outcome

Treatment of C-2 metastatic tumors with intraoperative transoral or transpedicular vertebroplasty and occipitocervical posterior fixation.

Metastatic spinal tumors of the atlantoaxial region are quite uncommon, and surgery is challenging. The aim in this study was to evaluate the safety and efficacy of transoral or transpedicular vertebroplasty combined with posterior fixation in C-2 metastatic disease. The authors collected from a hospital database all cases of C-2 metastatic tumor treated in the period from January 2009 to December 2012. Cases with histologically confirmed metastatic disease were included, but those with epidural tumorous propagation and signs of spinal cord compression were excluded. Five patients (3 females, 2 males) with osteolytic C-2 metastasis were eligible for this study. In 3 cases a purely posterior approach was taken to perform a dorsal open C-2 biopsy and transpedicular vertebroplasty followed by posterior occipitocervical fixation. In the other 2 cases a transoral C-2 biopsy and vertebroplasty were performed in combination with dorsal occipitocervical fixation during the same operative session. Patients were followed up with regular fluoroscopy, MRI, and CT studies as well as neurological examinations. During an average follow-up of 13 months (range 8-19 months), no surgical or neurological complications were associated with this combined approach. In all cases spinal stability and pain reduction were detected. The average pain score according to the visual analog scale was 3.5 after surgery (range 2-5); before surgery, the average score was 7 (range 6-8). The average volume of polymethylmethacrylate injected was 4 ml. The body and dens of the C-2 vertebra was filled more than 60% for each patient. In this small series, simultaneous intraoperative transoral or transpedicular vertebroplasty and dorsal occipitocervical fixation proved to be a safe and effective treatment for patients with osteolytic C-2 metastatic tumors. These techniques may provide excellent pain relief and improvements in quality of life. The true value of these combined techniques should be evaluated in larger series.

Operative technique for en bloc resection of upper cervical chordomas: extended transoral transmandibular approach and multilevel reconstruction.

Anterior exposure for cervical chordomas remains challenging because of the anatomical complexities and the restoration of the dimensional balance of the atlanto-axial region. In this report, we describe and analyze the transmandibular transoral approach and multilevel spinal reconstruction for upper cervical chordomas. We report two cases of cervical chordomas (C2 and C2-C4) that were treated by marginal en bloc resection with a transmandibular approach and anterior-posterior multilevel spinal reconstruction/fixation. Both patients showed clinical improvement. Postoperative imaging was negative for any residual tumor and revealed adequate reconstruction and stabilization. Marginal resection requires more extensive exposure to allow the surgeon access to the entire pathology, as an inadequate tumor margin is the main factor that negatively affects the prognosis. Anterior and posterior reconstruction provides a rigid reconstruction that protects the medulla and decreases axial pain by properly stabilizing the cervical spine.

Atlantoaxial epidural abscess secondary to grass awn migration in a dog

A two-year-old female Lucerne Hound was presented with a one-week history of signs of progressive neck pain, inappetence, apathy, and an elevated rectal temperature. Findings of magnetic resonance imaging (MRI) were consistent with a foreign body abscess in the epidural space at the level of the first and second cervical vertebrae. A left-sided dorso-lateral atlantoaxial approach was performed, revealing an epidural abscess containing a grass awn. The clinical signs resolved within three days of surgery and the dog made a full recovery. This case report shows that grass awns can migrate to the atlantoaxial region in dogs and MRI findings lead to a suspicion of caudo-cranial migration within the spinal canal.

Feasibility of atlantoaxial pedicle screws’ placement in children 6–8 years of age

The aims of this study were to evaluate the linear and angular dimensions of children's atlantoaxial pedicle using cadavers combined with axial computed tomography (CT) and to examine the feasibility of placing atlantoaxial pedicle screws (3.5 mm diameter) on the vertebrae of children 6-8 years of age. Fourteen cadaveric specimens, ranging in age from 6 to 8 years, were dissected to obtain their atlantoaxial vertebrae. We manually measured 12 linear anatomic parameters related to the atlantoaxial pedicle, its lateral mass, and the posterior arch under the vertebral artery groove. CT axial scanning of the atlantoaxial region was performed on 32 healthy children ranging in age from 6 to 8 years. The length of the atlantoaxial pedicles and the angle between the pedicle axis and the midline of the vertebral body were measured on the atlantoaxial transverse CT imaging. It is feasible to place a 3.5 mm screw in the atlantoaxial pedicle of children ranging in age from 6 to 8 years when the appropriate entry point and trajectory of the screw are chosen.

SAT0093 Quantification of Bone Marrow Edema by Using Magnetic Resonance Imaging for the Assessment of Neck Pain Only Marginally Reflects Clinical Evaluation in Patients with Rheumatoid Arthritis and Ankylosing Spondylitis

BackgroundDespite the differences in the pathogenesis of rheumatoid arthritis (RA) and ankylosing spondylitis (AS), neck pain is a frequent clinical symptom in both diseases that was recently shown to correlate...

Spinal Meningiomas: A Review

Meningiomas of the spinal axis have been identified from C1 to as distal as the sacrum. Their clinical presentation varies greatly based on their location. Meningiomas situated in the atlanto-axial region may present similarly to some meningiomas of the craniocervical junction, while some of the more distal spinal axis meningiomas are discovered as a result of chronic back pain. Surgical resection remains the mainstay of treatment, although advancements in radiosurgery have led to increased utilization as a primary or adjuvant therapy. Angiography also plays a critical role in surgical planning and may be utilized for preoperative embolization of hypervascular meningiomas.

Drainage of a ventral epidural atlantoaxial abscess via the transoral approach

We present a 28-year-old man with neck pain, fevers, elevated acute-phase reactant levels and progressive quadraparesis. He had a history of intravenous drug abuse. Contrast-enhanced cervical spine MRI revealed a heterogeneously enhancing mass in the anterior atlantoaxial region with spinal cord compression. The patient was taken emergently to the operating room for decompression. Although the transoral approach for access to the ventral atlantoaxial complex for resection of compressive inflammatory and neoplastic lesions is well described, reports of evacuation of infectious lesions via this route are limited. Thus, we report drainage of a ventral high cervical abscess via the transoral approach.

Developmental anatomy of the atlas and axis in childhood by computed tomography

The CT modality plays a central role in the diagnosis of cervical spine fractures. In childhood, radiolucent synchondroses between ossification centers can resemble fractures, and they can be the sites of fractures as well. Recognition of cervical spine fractures in children requires familiarity with normal developmental anatomy and common variants as they appear on CT scans. A convenience sample of 932 CT scans of the cervical spine accessible on the picture archiving and communications system (known as PACS) at a single children's hospital was examined. Scans were excluded from further analysis if they did not include the atlantoaxial region or were otherwise technically unsatisfactory; if the patient carried the diagnosis of a skeletal dysplasia; or if there were developmental lesions noted at other levels of the spine. No more than 1 scan per patient was analyzed. Synchondroses were graded as radiolucent, not totally radiolucent but still visible, or no longer visible. Their locations and symmetries were noted. The presence or absence of the tubercles of the transverse ligament was noted as well. After exclusions, 841 studies of the atlas and 835 studies of the axis were analyzed. The 3 common ossification centers of the atlas arose in the paired neural arches and the anterior arch, but in as many as 20% of cases the anterior arch developed from paired symmetrical ossification centers. The 5 common ossification centers of the axis arose in the paired neural arches, in the basal center, in the dentate center (from which most of the dentate process develops), and in the very apex of the dentate process. The appearance of each synchondrosis was noted at sequential ages. The tubercles for the transverse ligament generally did not appear until the ossification of the synchondroses of the atlas was far advanced. Anomalies of the atlas included anterior and posterior spina bifida, absence of sectors of the posterior arch, and anomalous ossification centers and synchondroses. Anomalies of the axis were much less common. What appeared possibly to be chronic, incompletely healed fractures of the atlas were discovered on review for this analysis in 6 cases. No fractures of the axis were discovered. There is substantial variation in the time course and pattern of development of the atlas, and anomalies are common. Some fractures of the atlas may escape recognition without manifest sequelae. Variation in the time course of the development of the axis is notable as well, but anomalies seem much less common.

A three-dimensional study of the atlantodental interval in a normal Chinese population using reformatted computed tomography

The atlantodental interval has been usually used for the evaluation of atlantoaxial instability. However, the asymmetry of the lateral atlantodental interval is occasionally found in healthy individuals. Controversy therefore exists as to the clinical significance of this asymmetry in patients after trauma. The purpose of this study was to determine the normal range of atlantodental intervals in normal individuals using reformatted computed tomography. In this study, C1-C2 vertebrae were imaged in 230 adult patients by a Lightspeed Vct CT (General Electric, CT, USA) with a slice thickness of 0.625 mm. After reformatting the original images, the anterior atlantodental interval (AADI) and lateral atlantodental interval (LADI) were measured. The AADI was found to be 1.83 ± 0.46 mm (0.9-3.4 mm) in males and 1.63 ± 0.43 mm (0.5-3.2 mm) in females. The AADI was significantly greater in males than in females (p < 0.05). The 95% confidence interval for AADI was 1.75-1.90 mm in males and 1.54-1.72 mm in females. No statistically significant differences were found between males and females in the left and right LADI, and LADI asymmetry. The left LADI was found to be 3.38 ± 0.87 mm (1.7-6.0 mm), and the right LADI was 3.42 ± 0.84 mm (1.7-5.9 mm) in males, while the left LADI was 3.30 ± 0.73 mm (1.5-5.3 mm) and the right LADI was 3.37 ± 0.92 mm (1.7-5.9 mm) in females. The 95% confidence interval for left LADI was 3.23-3.52 and 2.94-3.25 mm, and for right LADI was 3.27-3.56 and 3.18-3.56 mm in males and females, respectively. The mean asymmetry of LADI was 0.76 ± 0.66 mm (0.0-3.5 mm) in males and 0.73 ± 0.70 mm (0.0-3.7 mm) in females. The 95% confidence interval for LADI asymmetry was 0.65-0.87 mm in males and 0.59-0.88 mm in females. Most of the population was found to have an asymmetry ranging between 0.1 and 2.0 mm. The current study shows that LADI asymmetry is common in patients without any cervical spine abnormalities. LADI asymmetry may be a normal anatomic variant and there is no evidence to confirm that LADI asymmetry is a sensitive or specific indicator of traumatic atlantoaxial instability. Radiologists and clinicians should be aware of this normal range of asymmetry when interpreting CT scans of the atlantoaxial region.

Classification of Odontoid Destruction in Patients with Rheumatoid Arthritis Using Reconstructed Computed Tomography: Reference to Vertical Migration

To reveal the factors that determine the natural course of subluxation of occipital-cervical lesions in rheumatoid arthritis (RA). The atlanto-axial region is one of the most common locations for lesions in RA. Some cases progress from reducible atlanto-axial subluxation (AAS) to irreducible vertical migration, while others continue to exhibit reducible AAS. No study has revealed the factors that determine the natural course of subluxation. We focus on the odontoid as a key structure of the progression of occipito-cervical lesions and investigated this region in patients with RA using reconstructive computed tomography (CT) images, and analyzed factors in association with CT findings. Fifty-eight patients with RA and 40 age-matched controls, all women, were studied. Associated factors, including C-reactive protein, erythrocyte sedimentation rate, steroid usage, and the severity of local osteoporosis, were analyzed as measurements in association with odontoid destruction. The destruction of odontoid and atlanto-odontoid joint were common in patients with RA. The more destruction observed in the odontoid process, the greater is the degree of progression of vertical migration. Local osteoporosis is a significant factor in odontoid destruction, based on a cortico-cancellous index of 42% in cases of grade III odontoid destruction. The odontoid process is a key structure in the progression of occipito-cervical lesions in patients with RA.

Cervical arthropathy caused by gout: stabilisation without decompression

The cervical spine is a rare site where tophaceous gout has been identified. There are currently 15 described cases in the literature of gouty involvement of the cervical spine with only three cases involving only the atlanto-axial region. We add the fourth of such cases and only the second to be managed operatively.

Novel technique of reduction of a chronic atlantoaxial rotatory fixation using a temporary transverse transatlantal rod

Background context Chronic atlantoaxial rotatory fixation (AARF) is uncommon as acute AARF is easily reduced either spontaneously or by conservative methods. Various anterior and posterior surgical approaches for a chronic AARF have been reported because of the difficulty encountered in obtaining reduction. Purpose To describe a novel technique of reduction of a chronic AARF using a temporary transverse transatlantal rod. Study design Technical report. Methods A 13-year-old girl presented with an 8-month-old chronic AARF with typical torticollis and “cock-robin” posture of the head with a normal neurology. As closed reduction with skull traction for 2 weeks failed to reduce the deformity, the patient underwent C1–C2 fusion. C1 lateral mass and C2 pedicle screws were inserted under computer navigation. A temporary transverse rod across the atlas and axis was placed to secure a three-column fixation to derotate the subluxed atlas into anatomical alignment. Rods were then connected between the C1 lateral masses and the C2 pedicle screws and fusion obtained with autologous iliac crest grafts. Result Anatomic reduction of the atlantoaxial region was obtained without neural compromise, and satisfactory fusion was observed at 6-months follow-up. Conclusion A temporary transatlantal rod provides a secure anchor point for easy maneuverability for reduction of a chronic AARF and has the advantage of being used even in the absence of the posterior arch of the atlas.

Dorsal occipitocervical fusion--indications and results

This report will relate to our experience with the occipitocervical fusion with the y-plate, which we used in the treatment of 53 patients. 39 of the patients had rheumatoid arthritis. Other indications demanding surgery were posttraumatic conditions, degenerative and congenital lesions, osteomyelitis, tumor and psoriasis arthritis. Before surgery, all patients suffered from pain in the neck and/or in the back of the head. On a linear scale from 0 to 10, the pain was rated as 8.0 in average (range 4 to 10). 33 patients had an instability of the atlantoaxial region and 26 patients a basilar invagination of the odontoid. A cervical myelopathy was found in 23 cases. One surgeon fused the occiput to C2 in 30 cases, to C3-C5 in 14 cases and to C7-T2 in 9 cases. In 17 patients a resection of the odontoid had to be performed before fusion to adequately decompress the spinal cord. 31 of the patients could be controlled with a follow-up of at average 45.9 months. 16 patients had died. At the time of follow-up, the pain was rated as 2.1 in average (range 0 to 8). The myelopathy cleared up in all cases but 3.9 patients required further operations on the cervical spine. 5 patients developed an instability at the level(s) below the fusion and an enlargement of the fusion to these levels had been performed. The fusion rate was 98.1%. The results were satisfying in 25 (80.6%) and not satisfying in 5 patients (19.4%). These results show the effectiveness of the occipitocervical fusion with the y-plate in a wide range of applications. It offers advantages above other techniques.

Radiographic morphology of the cranial portion of the cervical vertebral column in Cavalier King Charles Spaniels and its relationship to syringomyelia

To compare radiographic morphology of the atlantoaxial region between Cavalier King Charles Spaniels (CKCSs) and dogs of other breeds and determine whether there was an association between radiographic morphology of the atlantoaxial region and syringomyelia in CKCSs. 65 CKCSs and 72 dogs of other breeds. The amount that the spinous process of the axis overlapped the dorsal arch of the atlas, the relative size of the spinous process of the axis, and the amount of widening of the atlantoaxial joint that occurred when the neck was moved from a neutral to a flexed position were measured on lateral radiographic projections of the atlantoaxial region. Magnetic resonance images were reviewed to identify CKCSs with syringomyelia. The amount of overlap of the atlas and axis and the relative size of the spinous process of the axis were significantly smaller in CKCSs than in dogs of other breeds. However, the amount of widening of the atlantoaxial joint that occurred when the neck was moved from a neutral to a flexed position was not significantly different between groups, and no association was detected between syringomyelia and excessive atlantoaxial joint space widening or between syringomyelia and an excessively small axial spinous process. Results suggested that radiographic morphology of the atlantoaxial region in CKCSs differs from morphology of that region in dogs of other breeds, but that these differences do not account for why some CKCSs develop syringomyelia and others do not.

Is mechanical deformation of the suboccipital vertebral artery during cervical spine rotation responsible for vertebrobasilar insufficiency?

The atlanto-axial region of the vertebral artery (VA) has traditionally been considered at risk for injury during cervical spine rotation, leading to compromised blood flow to the hindbrain and vertebrobasilar insufficiency or ischaemia (VBI). The anatomical relationships of the suboccipital VA (VA3) and related haemodynamic changes associated with cervical spine movements have been neglected, however. The present review aims to provide a new perspective on possible causes of reduced blood flow to the hindbrain, with particular reference to the functional anatomy of VA3 and related biomechanics of cervical spine rotation, to inform evidence-based practice. To support the hypothesis that it is VA3, not the VA in the atlanto-axial region, that is compressed or stretched during cervical spine rotation, current studies of blood flow changes in the VA distal to the region of rotation and possible arterial deformation were retrieved, using AMED, CINAHL, Embase, Pedro and PubMed, and reviewed. Possible sites for VA3 deformation, based on a re-examination of its anatomy and biomechanics, are described. However, no research reports of VA3 blood flow measurements associated with cervical spine rotation have been published to date. Five studies on blood flow changes in the intracranial VA after cervical spine rotation were reviewed. The subjects for four of these reports were young, healthy individuals, and the fifth included older patients and young non-patients. The analysis of these studies demonstrated that more rigorous control of variables is necessary before meaningful conclusions can be made. The paucity of studies of VA3 emphasises the need for research based on informed understanding of the anatomy and biomechanics of this area. This view on mechanical deformation of VA3 associated with cervical spine rotation as a possible cause of compromised blood flow to the hindbrain and VBI provides further argument for avoiding full-range or sustained cervical spine rotation in clinical practice.

The crowned dens syndrome. Evaluation with CT imaging

The purpose of this study was to verify the value of computed tomography (CT) in the diagnosis of the "crowned dens" syndrome, not only in crystal deposition diseases, but also in other rheumatic or nonrheumatic conditions. Thirty-eight patients (15 men and 23 women; mean age 55 years; age range 35-79) with neck pain were examined and divided into two groups: (1) patients already identified as rheumatic and referred for further investigation of the atlantoaxial region; (2) patients with symptoms confined to the cervical spine, with inconclusive radiographic findings. Unenhanced CT of the cervical spine (Tomoscan SR 7000 Philips, Eindhoven, Netherlands) was performed in all patients. There were 11 cases of rheumatoid arthritis (ten women and one man), two calcium pyrophosphate dihydrate crystal deposition disease (both women), one of systemic sclerosis (a woman), one of osteoarthritis (a man), one of seronegative arthritis (a man), four of neoplasm (one woman and three men) with suspected cervical involvement, one (a man) of haematological disease (lymphoma), one (a woman) of menopausal osteoporosis, ten (five men and five women) of recent or previous trauma with suspected involvement of the skull base and first cervical vertebrae and six of unknown painful cervical dysfunction (three men and three women). CT demonstrated calcific deposits around the dens in 12 patients (three men and nine women), in the transverse and alar ligaments, and in the anterior atlantooccipital membrane. CT revealed horseshoe- or crown-like calcification surrounding the odontoid process. In our series, other rheumatic diseases, especially rheumatoid arthritis, showed similar irregular calcifications of the atlantoaxial joint. Discussion. In calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, the spine may be the only site of involvement, generally asymptomatic. Crystals located in the transverse ligament of the atlas give rise to the crowned dens syndrome, usually in patients affected by severe degenerative lesions of the atlantoaxial joint and peripheral chondrocalcinosis. Symptoms may be absent, or a neurological compressive syndrome may develop. Symptoms tend to worsen with age. The diagnosis is not always easy, as the symptoms are similar to those of other diseases, such as meningitis, cervicobrachial pain, occipitotemporal headache, calcific tendinitis of the longus colli muscle, spondylodiscitis and retropharyngeal abscess. CT is the gold standard in identifying crowned dens syndrome, as it is able to depict the shape and site of calcification and any bone erosions. Radiography of other joints (wrist, knee, pubic symphysis) may help to ascertain whether the disease is due to calcium pyrophosphate dihydrate or hydroxyapatite crystals, and is therefore recommended for routine patient management. Magnetic resonance imaging (MRI) is indicated for the study of neurological complications.

Endoscopic transoral surgery for craniovertebral junction anomalies

Craniovertebral junction (CVJ) anomalies continue to be challenging for neurosurgeons because of the complex anatomy of this region. To date, microsurgical decompression via a transoral route is the standard treatment for anteriorly located compressive lesions of the cervicomedullary junction (CMJ). The results obtained by minimizing surgical trauma are fewer complications, shorter hospital stays, and reduced overall psychological burden. Endoscopic surgery is becoming a leading modality in minimally invasive neurosurgical treatment. The authors performed surgery in 11 patients with irreducible osseous dislocations resulting from CVJ abnormality during a 2-year period. Anterior CMJ decompression was achieved in all patients by performing neuroendoscopically controlled transoral excision of bone and soft tissues. The surgical technique and results will be discussed. The use of the endoscope offers several advantages in cases requiring a transoral approach to the lower clivus and atlantoaxial region. The use of minimally invasive endoscopic techniques has the potential to reduce the need for a wider cranial base opening and to decrease postoperative complications.