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Minimally invasive atlantoaxial fixation with a polyaxial screw-rod construct: technical case report.

OBJECTIVE AND IMPORTANCE: Posterior C1-C2 fusion with polyaxial screw and rod fixation has become an accepted means of atlanto-axial stabilization. We describe a novel technique for minimally invasive placement of C1 lateral mass screws and C2 pedicle screws for polyaxial screw-rod stabilization. CLINICAL PRESENTATION: The patient presented with a history of chronic neck pain, as well as a 6-month history of weakness and paresthesias involving her left hand. An Os Odontoideum was present on computed tomographic imaging of the cervical spine. Significant instability was noted on flexion-extension imaging, and magnetic resonance imaging demonstrated mild T2 signal change within the spinal cord. TECHNIQUE: Under fluoroscopic guidance, serial dilators were passed through a 2.5 cm paramedian skin incision to allow placement of an expandable tubular retractor. The exposure was centered on the C2 lateral mass. After expansion of the retractor and further subperiosteal dissection, the C1 and C2 lateral masses were visible permitting placement of a polyaxial screw rod construct. This procedure was carried out bilaterally. CONCLUSION: Placement of C1 lateral mass and C2 pedicle screws using minimally invasive techniques is technically feasible.

Adult↗

Manifestations of Pott's disease in the head and neck.

Tuberculosis (TB) of the spine, or Pott's disease, is a rarely encountered clinical disorder in the United States today. However, Pott's disease should be strongly suspected in a person who presents with a destructive lesion of the spine involving adjacent vertebrae or a retropharyngeal mass which extends across the midline. The most common presenting signs and symptoms are pain and spinal deformity. The PPD skin test is usually positive, but unlike TB of the larynx, the chest roentgenogram is almost always negative. Diagnosis may be confirmed by needle aspiration or incisional biopsy and culture. The otolaryngologic literature has not previously addressed this clinical entity, thus, our experience with a patient with a retropharyngeal mass and quadriplegia diagnosed as Pott's disease will be presented. Subsequent medical therapy, stabilization, and odontoidectomy resulted in resolution of his neurological deficit. The incidence, pathogenesis, clinical features, and management of Pott's disease will be discussed.

Adult↗

[Inside-outside occipito-cervical fixation: technical report].

The clinical knowledgement of biomechanics of atlantoaxial complex have been proved that progressive instability has a mandatory occurrence after anterior decompression of the craniocervical junction. We report the occípitocervical fixation so called inside-outside technique, originally described by Pait et al. appliedin in two patients whom underwent odontoidectomy. The occipitalcervical fixation technique consist in the use of a titanium rod bended according with occipital cervical angle placed and fixed laterally over the cervical spine. The rod is fixed to the occipital bone by mean of placement a screw which flat portion is positioned onto the epidural space. In the cervical spine the rod is attached to transarticular screws placed at the superolateral quadrant of the articular mass. In the axis the screw is introduced through the pars interarticularis finishing at the axis body or the lateral mass of the atlas. This technique proved to be safe and easily applied in the patients whom underwent this surgical procedure.

Adult↗

Aberrant retropharyngeal internal carotid artery in a child with spondyloepimetaphyseal dysplasia and cleft palate.

In a patient with spondyloepimetaphyseal dysplasia and cleft palate, the course of the internal carotid artery was aberrant. Prompt identification of this anomaly is critical, because operative fatality can occur if the defect is unrecognized. This case illustrates the occurrence of this vascular anomaly and focuses on options for radiologic identification and evaluation of the defect.

Carotid Artery, Internal↗

Osteoarthrosis of the atlanto-axial joints. Long-term follow-up after treatment with arthrodesis.

We evaluated the results for fifteen patients in whom symptomatic osteoarthrosis of the atlanto-axial joints had been treated with an atlanto-axial or occipitocervical arthrodesis between 1973 and 1990. Thirteen patients had long-term follow-up (average duration, seven years and two months; range, four years and two months to nineteen years and two months). The two remaining patients had died: one, four days postoperatively, from a cardiopulmonary arrest, and the other, one year and eight months postoperatively, from complications related to bladder cancer. Preoperatively, all fifteen patients reported pain in the occipitocervical region that increased with any attempt at rotation of the neck and was unresponsive to immobilization with a collar and to analgesics. The average duration of the symptoms before the arthrodesis was three years. One patient had acute quadriparesis. All patients had radiographic evidence of oesteoarthrosis involving the lateral atlanto-axial articulations. Four patients had atlanto-axial instability with an average of five millimeters (range, three to ten millimeters) of motion at the anterior atlanto-odontoid interval. Six patients had an associated spontaneous subaxial fusion, which was secondary to osteoarthrosis in five; three of the five also had atlanto-axial instability. Fourteen patients were managed with a posterior arthrodesis and one, with an anterior transoral arthrodesis. The procedures were performed to relieve pain, to stabilize the atlanto-axial joints, and to restore neurological function. Of the fourteen patients who were followed, thirteen had a solid fusion and one had a stable pseudarthrosis. The patient who had quadriparesis recovered. At the latest follow-up evaluation, thirteen patients had an excellent result and one had a fair result as determined with use of a modification of the criteria of Robinson et al. There were no poor results. Atlanto-axial arthrodesis can effectively relieve occipitocervical pain and correct atlanto-axial instability secondary to osteoarthrosis.

Aged↗

Diagnosing basilar invagination in the rheumatoid patient. The reliability of radiographic criteria.

BACKGROUND: Basilar invagination can be difficult to diagnose with plain radiography in patients with rheumatoid arthritis. Although numerous radiographic criteria have been described, few studies have addressed the reliability of these parameters in the rheumatoid population. The purpose of the present study was to validate and compare the most widely accepted plain radiographic criteria for basilar invagination in this patient population. METHODS: Cervical radiographs of 131 rheumatoid patients were examined. Of these patients, sixty-seven (twenty-nine with basilar invagination and thirty-eight without it) were also evaluated with tomograms, magnetic resonance imaging, and/or sagittally reconstructed computed tomography scans to detect the presence of basilar invagination. Three observers who were blinded with regard to the diagnosis independently scored each radiograph as positive, negative, or indeterminate according to the established criteria for invagination proposed by Clark et al., McRae and Barnum, Chamberlain, McGregor, Redlund-Johnell and Pettersson, Ranawat et al., Fischgold and Metzger, and Wackenheim. Interobserver and intraobserver variability, sensitivity, specificity, total percentage of correct results, and negative and positive predictive values were determined for each criterion as well as for various combinations of the criteria. RESULTS: No single test had a sensitivity and a negative predictive value of greater than 90% as well as a reasonable specificity and a reasonable positive predictive value. The combination of the Clark station, the Redlund-Johnell criterion, and the Ranawat criterion, scored as positive for basilar invagination if any of the three were positive, proved to be better than any single criterion; the sensitivity of the combined criteria was 94%, and the negative predictive value was 91%. CONCLUSIONS: A screening test for basilar invagination should have a high sensitivity and a high negative predictive value, so that the disease will not be missed, and yet be specific, so that the disease will not be overdiagnosed. Our data suggest that none of the widely utilized plain radiographic criteria meet these goals. We recommend that measurements be made according to the methods described by Clark et al., Redlund-Johnell et al., and Ranawat et al. and, if any of these suggests basilar invagination, tomography or magnetic resonance imaging should be performed. Since approximately 6% of the cases of basilar invagination in rheumatoid patients would still be missed with this approach, tomography or magnetic resonance imaging should be performed on a rheumatoid patient whenever plain radiographs leave any doubt about the diagnosis of basilar invagination.

Adult↗

Stability analysis of craniovertebral junction fixation techniques.

BACKGROUND: Craniovertebral arthrodesis in the upper cervical spine is challenging because of the high degree of mobility afforded by this region. A novel method for achieving atlantoaxial fixation with use of polyaxial screws inserted bilaterally into the lateral masses of C1 and transpedicularly into C2 with longitudinal rod connection has recently been introduced. The question remains as to whether this technique provides adequate stability when extended cephalad to include the occiput. The purpose of this study was to determine the primary stability afforded by this novel construct and compare its stability with the current standard of bilateral longitudinal plates combined with C1-C2 transarticular screws. METHODS: We used ten fresh-frozen human cadaveric cervical spines (C0-C4). Pure moment loads were applied to the occiput, and C4 was constrained during the testing protocol. We evaluated four conditions: (1) intact, (2) destabilized by means of complete odontoidectomy, (3) stabilization with longitudinal plates with C1-C2 transarticular screw fixation, and (4) stabilization with a posterior rod system with C1 lateral mass screws and C2 pedicle screws. Rigid-body three-dimensional rotations were detected by stereophotogrammetry by means of a three-camera system with use of marker triads. The range of motion data (C0-C2) for each fixation scenario was calculated, and a statistical analysis was performed. RESULTS: Destabilization of the specimen significantly increased C0-C2 motion in both flexion-extension and lateral bending (p < 0.05). Both fixation constructs significantly reduced motion in the destabilized spine by over 90% for all motions tested (p < 0.05). No significant differences were detected between the two constructs in any of the three rotational planes. CONCLUSIONS: Both hardware systems provide equivalent construct stability in the immediate postoperative period when it is critical for the eventual success of a craniovertebral arthrodesis. On the basis of this work, we believe that the decision to use either construct should be determined by clinical rather than biomechanical concerns.

Aged↗

Pseudogout showing meningoencephalitic symptoms: crowned dens syndrome.

We report a 70-year-old man who presented symptoms resembling those of meningoencephalitis and who was subsequently diagnosed as having a crowned dens syndrome. The patient exhibited severe neck pains, headache, high fever and a pain in his knee joints together with symptoms of the central nervous system. The patient's cerebrospinal fluid was almost clear and showed no sign of viral infection. An analysis of the synovial fluid in the right knee joint revealed typical calcium pyrophosphate dehydrate crystal deposition and a diagnosis of pseudogout was therefore made. A tomographic examination of the neck showed periodontoid calcification. The patient was first treated with non-steroidal anti-inflammatory drug, but its effect was only minimal. On the other hand, the administration of corticosteroid resulted in a dramatic improvement in his condition.

Aged↗

Bilateral vertebral artery occlusion secondary to atlantoaxial dislocation with os odontoideum: implication for prophylactic cervical stabilization by fusion--case report.

A 27-year-old male presented with an unusual atlantoaxial dislocation associated with os odontoideum, after suffering sudden onset of significant neurological deterioration. Angiography demonstrated simultaneous occlusion of the bilateral vertebral arteries assumed responsible for the devastating neurological deficits. He initially underwent cervical immobilization with a Crutchfield tong for 2 months and subsequent posterior fusion using an iliac bone graft and wires. The neurological symptoms gradually subsided, and 5 years later good healing of the bone graft without instability and ample subarachnoid space around the spinal cord were radiologically confirmed. Early prophylactic stabilization of atlantoaxial dislocation due to os odontoideum is recommended to prevent a poor outcome. Careful angiographic evaluation of the vertebrobasilar circulation is important for management of patients with os odontoideum.

Adult↗

Pediatric cerebellar infarction caused by atlantoaxial subluxation--case report.

An 11-year-old girl developed cerebellar infarction presenting as a posterior fossa mass lesion after stretching and flexing her neck. Cerebral angiography demonstrated irregular narrowing of the right vertebral artery at the C2 level and x-rays of the upper cervical spine showed atlantoaxial subluxation with os odontoideum. She underwent surgical decompression with removal of infarcted tissue. The cerebellar infarction probably resulted from occlusion of the vertebral artery, followed by brain swelling due to recanalization.

Atlanto-Axial Joint↗

Retro-odontoid massive calcium pyrophosphate crystal deposition--case report.

An 86-year-old male presented with progressive myelopathy due to retro-odontoid massive deposits of calcium pyrophosphate dihydrate (CPPD) crystals. Magnetic resonance imaging revealed a non-enhanced isointense extradural mass on the T1-weighted image and heterogeneously intense mass on the T2-weighted image. Computed tomography showed typical punctate and linear calcifications within the mass. The mass was resected via a lateral approach resulting in marked improvement of the symptoms. Histological examination revealed birefringent rhomboid crystals consistent with CPPD. CPPD deposition should be considered in the differential diagnosis of retro-odontoid extradural mass because surgical therapy is beneficial even for elderly patients.

Aged↗