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PubMed1989

[Indications and technic of transoral dens resection in craniocervical dysplasia].

Compressive lesions of the brain stem caused by ventrally or dorsally located bony malformations of the posterior skull base and the upper cervical spine show diffuse neurological signs and symptoms. They can imitate multiple sclerosis, cerebellar tumours, Ménière's disease and "Ménière-like" otological symptoms. Therefore, the otologist is involved in diagnosis and therapy of cranio-cervical dysplasia. At present dysplasia is differentiated into an anterior and posterior form of the disease. The most common lesion in the anterior form is brain stem compression by the high located dens axis. Therefore, transoral surgical removal of the dislocated odontoid process is the logical form of treatment and should be performed in patients with severe complaints. The technique used for the transoral resection of the odontoid process is described in detail. In 7 patients having the anterior type of the cranio-cervical dysplasia we performed a transoral resection of the elevated odontoid process. The results obtained were convincing with all patients. No intraoperative or postoperative complications were seen. Hearing impairment was not changed, neurological deficits and particularly vertigo improved. Follow-up examinations did not show any disturbances of head movements or remarkable dislocations of the kraniozervikal joints.

Adult↗
PubMed2000

Surgical treatment of muscular torticollis for patients above 6 years of age.

Eighteen patients with congenital muscular torticollis, aged 6-22 (average 11) years, underwent surgical releases of the contractive bands. There were 8 boys and 10 girls. Preoperative open mouth radiograph of the odontoid process in 16 patients showed asymmetry of articular facets of the axis and tilt of the odontoid process to the side of the torticollis. Sixteen patients received bipolar releases, the others received distal releases. After the operation, a neck collar was applied and an exercise program was started. At an average follow-up of 5 years and 7 months, there were excellent or good results in 10 patients. All of the patients except 2 showed improvement of the facial asymmetry and all except 1 had a satisfactory range of motion of the neck. One patient underwent a second operation due to recurrence. The follow-up radiographs showed improvement of the tilt of the odontoid process, but the asymmetry of the articular facets of the axis persisted. We suggest that bipolar release is the treatment of choice for congenital muscular torticollis in patients of more than 6 years of age. To determine the influence of a bipolar release on the functions of the cervical spine, longer follow-up intervals are needed.

Adolescent↗
PubMed2006

Anterior odontoid fixation using a 4.5-mm Herbert screw: The first report of 20 consecutive cases with odontoid fracture.

BACKGROUND: Anterior screw fixation provides the best anatomical and functional results for odontoid process fracture (type II and "shallow" type III) with intact transverse ligament. The purpose of this study is to evaluate the clinical results of the 4.5-mm-diameter cannulated Herbert screw in the anterior odontoid fixation. METHODS: From May 2003 to November 2005, 20 consecutive cases of types II and III odontoid process fractures were treated with anterior screw fixation using a 4.5-mm Herbert screw. The Herbert screw has double threads, with different pitches on the distal and proximal ends. It has no head, so it can be inserted through articular cartilage and buried below bone surface. RESULTS: There were 16 male and 4 female patients whose ages ranged from 15 to 76 years (mean, 43.7 years). The fracture type was type II-A in 4 patients, II-N in 9 patients, II-P in 5 patients, and III in 2 patients. The range of follow-up was 3 to 36 months (mean, 18.6 months). There were an overall bone fusion rate in 17 cases (85%), fibrous union in 1 (5%), and nonunion in 2 (10%). Overall, complication unrelated to hardware occurred in the one (postoperative dysphagia) without complication-related hardware failure. CONCLUSIONS: The Herbert screw is very useful in anterior fixation for types II and III odontoid process fractures. This series showed successful clinical results comparable with that of the 3.5-mm cannulated cancellous screw and distinct advantages over conventional screws in the aspect of biomechanical properties and less invasiveness.

Adolescent↗
PubMedDate not supplied

CT and myelogram findings of os odontoideum.

We reviewed the findings of CT and myelogram of cases of os odontoideum. The diagnosis was confirmed by conventional tomogram in all these cases. Four cases were further confirmed by trans-oral decompression. Cartilage was found between the os odontoideum and the odontoid process during operation in these 4 cases. Four of them had no history of trauma and 2 of them had an associated anomaly; one was Down's syndrome, and the other was barrel chest and congenital dislocation of hips. CT findings of os odontoideum in these cases were a constriction and/or a gap of bony structure between the os odontoideum and the odontoid process. Myelograms showed spinal stenosis as a result of atlanto-axial dislocation, or anterior extradural compression from overgrown cartilage and posteriorly dislocated tip of shortened odontoid process.

Adolescent↗
PubMed2005

Biomechanical evaluation of a bioresorbable odontoid screw.

OBJECT: The authors tested the ability of a resorbable cannulated lag screw composed of a polylactide copolymer to repair Type II odontoid fractures. The resorbable screw was evaluated for its ability to restore strength and stiffness to the fractured odontoid process compared with traditional titanium screws. METHODS: Type II odontoid fractures were created in 14 human cadaveric C-2 vertebrae by applying a posterolaterally directed load and piston displacement was measured. Seven of these specimens were repaired using metal screws and seven were repaired using resorbable screws. Specimens were reinjured using the same mechanism as the initial fracture. Values of ultimate strength and stiffness during failure were statistically compared between metal and resorbable screws and between initial fracture and reinjury. CONCLUSIONS: The stiffness and ultimate strength during initial fracture were significantly greater than those during reinjury in specimens repaired using resorbable screws or titanium screws (p < 0.001). The resorbable and titanium screws both restored 31% of the initial ultimate strength of the intact specimen (p = 0.95). The stiffness of the fractured odontoid process was restored to 15 and 23% of its initial value by repair with resorbable and metal screws, respectively (p = 0.07). The mode of failure in resorbable screws was usually breakage or bending, whereas that in metal screws was consistently cutout of the proximal shaft of the screw through the anterior C-2 vertebral body.

Absorbable Implants↗
PubMed1999

[Anterior screw fixation combined with posterior interlaminar fusion for fracture of axis: report of two cases].

Two cases of axis fracture are reported. Traffic accidents were the cause of injury in both cases. The odontoid process was dislocated anterolaterally with fracture of the lateral mass of the axis in both cases. In Case 1 good alignment of the atlas and axis could not be maintained even with a Halo-vest. The case 2 patient with spinal cord compression caused by dislocation of the axis was referred to our hospital 8 weeks after the accident. Both cases were surgically treated in a similar fashion. Because of the lateral mass fracture and lateral displacement of the atlas relative to the axis, posterior screw fixation with interlaminar fixation (Magerl) was thought to carry a risk of causing damage to the vertebral artery. Because of this, anterior screw fixation combined with posterior wiring was conducted. First, the odontoid process was fixed anteriorly by a screw because it was able to be placed back in good alignment while the patient was in the supine position. Then, the posterior C1-2 interlaminar wiring with iliac bone graft was added. Rigid fixation was obtained without any complication. Various kinds of fixation, such as posterior interlaminar wiring, odontoid screw fixation and Magerl's fixation, have been reported for the treatment of unstable axis fracture. Among them Magerl's method has been regarded as the most stable. When it is not applicable, combination of the first two methods can be an alternative way of treatment for this odontoid process fracture.

Accidents, Traffic↗
PubMed1978

Cervical-spine instability in children with Down syndrome (trisomy 21).

Eighty-five children with Down syndrome, between sixteen months and eighteen years old, were evaluated for instability of the cervical spine at the atlanto-axial joint. The mean atlas-odontoid process interval was three millimeters in flexion and two millimeters in extension. Ten patients (12 per cent) exhibited abnormal intervals (4.5 millimeters or more) during either flexion or extension. The configuration of the odontoid process was considered normal in eighty patients and abnormal in another five patients (6 per cent). The correlation between the thickness of the interval and the degree of ligament laxity was statistically significant, as was the correlation between ligament laxity and age. Of the ten patients with an increased atlas-odontoid process interval, neurological deficit (hyperreflexia and clonus) developed in only one after a one-year follow-up.

Adolescent↗
PubMed1997

Odontoid Fractures: Evaluation and Management.

Fractures of the odontoid process are uncommon injuries. Fracture displacement, compromised blood supply, comminution, and iatrogenic distraction have all been implicated in the reported high rates of nonunion. Plain radiography, polytomography, and computed tomography are all useful in delineating the fracture pattern. Magnetic resonance imaging has been recommended for evaluating associated ligamentous injuries and may be helpful in detecting occult cervical spine fractures. Type I fractures are avulsion fractures of the tip of the odontoid process. These rare injuries require only external immobilization with an orthosis if there is no associated ligamentous injury. Type II fractures occur at the junction of the odontoid process and the body of the axis. These are the most common odontoid fractures and are associated with a high incidence of nonunion. Nondisplaced fractures should be treated with halo immobilization for 8 to 12 weeks, with careful clinical and radiographic monitoring. Displaced fractures should be considered for operative treatment, either with atlantoaxial arthrodesis or anterior screw fixation. Type III fractures, which extend into the body of the axis through cancellous bone, are treated with closed reduction and halo immobilization.

Journal Article↗
PubMed1985

Medically reversible quadriparesis in tophaceous gout.

This case report presents a successful nonoperative outcome of a type II odontoid fracture secondary to severe tophaceous gout. The patient presented with spastic quadriparesis and tophaceous involvement of the odontoid process with fracture and C1-C2 instability. He refused surgery. However, his odontoid process stabilized with the used of a collar, and he regained almost normal strength plus independence in self-care and ambulation, demonstrating that an unstable type II odontoid fracture secondary to tophaceous gout can stabilize with conservative management.

Axis, Cervical Vertebra↗
PubMed1979

Cervical spine fusion in rheumatoid arthritis.

Spinal fusion for deformity of the cervical spine was done in thirty-three patients with rheumatoid arthritis. The average follow-up was three years. The deformities present were atlano-axial subluxation, superior migration of the odontoid process into the foramen magnum, and subaxial subluxation of the vertebral bodies. We devised a classification of the pain and the neural involvement in these patients and a new method of measuring superior migration. The surgical procedures for treating instability, intractable pain, or neural involvement, or a combination of the three, were: (1) a Gallie fusion of the first and second cervical vertebrae for atlanto-axial subluxation, (2) a fusion of the occiput and the second cervical vertebra for superior migration of the odontoid process, and (3) a posterior fusion for subaxial subluxation. The occiput was included in the fusion if superior migration of the odontoid process was demonstrated. The results show that four of five patients who had an anterior fusion had no improvement. Twenty-five patients had posterior fusion; in seventeen the condition was improved, in five there was improvement, and in three the condition was worse. Of nineteen patients with neural involvement, the condition was improved in eight, it was unchanged in seven, and it was made worse in two. There were three postoperative deaths and six additional unrelated deaths within two years of surgery. There were five pseudarthroses.

Adult↗
PubMed1989

[Traumatic dislocations/dislocation fractures of the cervical spine. Neurosurgical experiences in 42 surgical patients].

Neurosurgical results in 42 patients operated on for cervical spine dislocations or fracture-dislocations are described. The study shows that repositioning with the Crutchfield extension is almost always successful. Imbricated fractures must occasionally be repositioned surgically (2 cases). A strikingly large proportion of patients (50%) in whom decompression was carried out ventrally were found to be suffering from traumatic disc hernia in the lower cervical spine. This was often accompanied by laceration of the posterior longitudinal ligament. Operative stabilization of unstable fractures, especially pseudarthrosis, of the odontoid process was performed in the main by dorsal immobilization (blocking) at C1/C2 (pelvic bone chips/wiring), whereby the residual rotational limitation was only of moderate degree and well tolerated subjectively. Two patients in whom stabilization was achieved in this way developed secondary ossification of the old pseudarthrosis of the odontoid process. In 2 cases the operation was carried out by the transbuccal route, again with the use of pelvic bone chips. Operative stabilization below C2 was performed 15 times using the ventral approach only, namely 13 times by Cloward's method and twice by Caspar's method. A combined ventrodorsal approach was used a total of 13 times in patients with severely damaged dorsal ligaments; here we made use ventrally of autologous pelvic bone chips, dorsally of wire osteosynthesis. The results were in the main good in respect of repositioning, uniformly good in respect of stability. In the great majority of cases with medullary or radiculomedullary deficits, the operation resulted in complete healing or at least an improvement, namely in 75% of patients with lesions of the odontoid process and in 81% of those with lesions below C2. In the second part of the study, the advantages and disadvantages of the various methods are set out and discussed in the light of recent advances and in particular of operative experience with tumours in the region of the cervical spine.

Adult↗
PubMed1996

Computed tomographic scans of minimally displaced type II odontoid fractures.

OBJECTIVE: To determine the computed tomography (CT) appearance of minimally displaced type II odontoid fractures and the optimal protocols to evaluate these fractures by CT. MATERIALS AND METHODS: The CT scans of five patients with minimally displaced type II odontoid fractures and 71 patients without odontoid pathology were reviewed for signs of fracture. A phantom consisting of a cadaver specimen with a type II odontoid fracture was evaluated with several protocols on four CT scanners. The protocols differed in slice thickness and reconstruction algorithm. Helical scanning was also performed, and parasagittal and coronal reformations were created from each image set. MAIN RESULTS: Multiple cortical disruptions longer than 1 mm were demonstrated on the scans of all five patients with type II odontoid fractures. Only three of the 71 patients without odontoid fractures had multiple cortical disruptions, and none were longer than 1 mm. In the phantom study, thinner sections demonstrated cortical disruptions better than thicker sections. Similarly, images reconstructed with a bone reconstruction algorithm demonstrated the cortical disruptions better than images reconstructed with a soft-tissue reconstruction algorithm. Helical scans (1 mm thick) adequately demonstrated the reduced Type II odontoid fracture. Parasagittal and coronal reformations failed to demonstrate a fracture line through the base of the odontoid process on all image sets. CONCLUSIONS: Cortical disruptions greater than 1 mm and multiple cortical disruptions may be the only findings of odontoid fractures and should suggest the diagnosis. Evaluation of potential type II odontoid fractures is improved as CT section thickness is reduced (down to 1 mm) and is also improved by use of a bone reconstruction algorithm. The apparent absence of a fracture line through the base of the odontoid process on parasagittal or coronal reformations does not rule out the diagnosis.

Cadaver↗
PubMed1993

Evaluation of the craniocervical junction in Down syndrome: correlation of measurements obtained with radiography and MR imaging.

Measurement of the atlas-dens interval is the radiographic standard for identification of patients with Down syndrome at high risk for neurologic injury from spinal cord compression. In 17 pediatric patients with Down syndrome, measurements of the atlas-dens interval, distance between the clivus and posterior odontoid process, and width of the neural canal obtained with plain radiographs were compared to predict the width of the subarachnoid space on magnetic resonance (MR) images. In all patients, cervical radiography and craniocervical MR imaging were prospectively performed during lateral flexion and extension. The width of the subarachnoid space was measured with MR imaging. When the 95% confidence interval for correlation coefficients of regression was used, subarachnoid space width on MR images correlated with neural canal width on radiographs better than with either atlas-dens interval or clivus-posterior odontoid process distance (P = .05). Measurement of neural canal width is a better predictor of potential spinal cord compression than the atlas-dens interval or clivus-posterior odontoid process distance and should be emphasized in screening examinations performed with plain radiography.

Adolescent↗
PubMedDate not supplied

Perception and reality in a case of suspected cervical fracture.

The case of a 36-year-old female, who following a road accident, had a cervical whiplash, is discussed. A radiographic examination of the affected region was performed at the Emergency Department. It showed a transverse radiolucent line at the basal odontoid process of the axis. A definitive interpretation was not possible and fracture of the odontoid process of the axis was suggested as differential diagnosis. On coronal CT reconstruction the presence of this fracture was ruled out. The line seen on the film was actually the product of a psychophysiologic visual illusion known as "Mach band". The use of conventional radiography correlated with digital CT images shows that the practical application of Mach band theory allows a better differentiation between normal and pathologic anatomy.

Accidents, Traffic↗
PubMed2000

Use of calcitonin for the treatment of an odontoid fracture. Case report.

The authors report on the efficacy of nonsurgical treatment of an older patient with a fractured odontoid process. The patient, an 85-year-old woman, had multiple medical problems that put her at an increased surgery-related risk. Therefore, an alternative approach was elected, including immobilization with a Philadelphia collar and the provision of calcitonin nasal spray. Bone union and clinical recovery were achieved within 8 weeks of initiating the nasal calcitonin therapy (12 weeks postinjury). Considering the patient's age, comorbidities, and the severity of the fracture, the recovery period was unusually short. The authors believe that calcitonin played a pivotal role in the healing process of the fractured odontoid bone. There is no question that the fusion in this patient could be unrelated to the medical therapy. This description of one patient, as well as the lack of a large randomized study, precludes any scientific conclusions. Nevertheless, the authors believe that the development of a successful fusion in this high-risk patient should be reported as an observation that merits confirmation and study. The authors also discuss the physiological effects of calcitonin and the research and clinical experience with this hormone in different conditions affecting bone.

Administration, Intranasal↗
PubMed2001

Calcitonin and spinal fusion.

The authors report on the efficacy of nonsurgical treatment of an older patient with a fractured odontoid process. The patient, an 85-year-old woman, had multiple medical problems that put her at an increased surgery-related risk. Therefore, an alternative approach was elected, including immobilization with a Philadelphia collar and the provision of calcitonin nasal spray. Bone union and clinical recovery were achieved within 8 weeks of initiating the nasal calcitonin therapy (12 weeks postinjury). Considering the patient's age, comorbidities, and the severity of the fracture, the recovery period was unusually short. The authors believe that calcitonin played a pivotal role in the healing process of the fractured odontoid bone. There is no question that the fusion in this patient could be unrelated to the medical therapy. This description of one patient, as well as the lack of a large randomized study, precludes any scientific conclusions. Nevertheless, the authors believe that the development of a successful fusion in this high-risk patient should be reported as an observation that merits confirmation and study. The authors also discuss the physiological effects of calcitonin and the research and clinical experience with this hormone in different conditions affecting bone.

Administration, Intranasal↗
PubMed1993

Transoral-transpharyngeal approach to the upper cervical vertebrae.

The classical operative approaches to the cervical spine include the posterior one and the anterior exposure along the sternomastoid muscle. However, neither of these are helpful in exposing the upper cervical vertebrae, especially the odontoid process, atlas, and axis. We have used the transoral-transpharyngeal exposure for lesions of the odontoid process and upper (first to third) cervical vertebrae in six patients. The pathologic processes included rheumatoid disease and fracture of the cervical vertebrae, suspected tumor with compression of the spinal cord, basilar invagination, and compression of the medulla. In all six patients, the exposure was excellent, and postoperative morbidity was minimal. Tracheostomy was performed routinely in all these patients. In five patients, vertebral stabilization was performed as a secondary procedure a few days after the initial anterior decompressive surgery. The transoral-transpharyngeal approach appears to be relatively easy. It is associated with minimal complications and provides excellent exposure of the odontoid and upper cervical vertebrae for a microneurosurgical approach. Modifications of this approach include incision of the soft palate, excision of a portion of the hard palate, and, occasionally, transmandibular median labio-mandibulo-glossotomy (Trotter's) approach. Although the technique was described initially approximately 35 years ago, this neglected anatomic approach will facilitate cooperative efforts between head and neck surgeons and neurosurgeons.

Adult↗
PubMed2004

CT evaluation of the pattern of odontoid fractures in the elderly--relationship to upper cervical spine osteoarthritis.

Odontoid fractures are common in the elderly following minor falls. Almost all of them have osteoarthritis of the cervical spine below the axis vertebra. As a result, there is increased stress on the spared upper cervical spine, resulting in a higher incidence of injuries. As movement in the upper cervical spine involves participation of five joints, degeneration in any one particular joint may affect the biomechanics of loading of the upper cervical spine. We aimed to analyse the relationship of odontoid fractures to the pattern of upper cervical spine osteoarthritis in the elderly. We studied the CT-scan images of the cervical spine in 23 patients who were over the age of 70 years and had odontoid fractures. In each patient, the type of odontoid fracture and the characteristics of the degenerative changes in each joint were analysed. Twenty-one of 23 patients had Type-II odontoid fractures. The incidence of significant atlanto-odontoid degeneration in these individuals was very high (90.48%), with relative sparing of the lateral atlantoaxial joints. Osteoporosis was found in 13 of 23 patients at the dens-body junction and in seven of 23 patients at the odontoid process and body of the axis. With ageing, progressively more severe degenerative changes develop in the atlanto-odontoid joint. These eventually obliterate the joint space and fix the odontoid to the anterior arch of the atlas. In contrast, the lateral atlantoaxial joints are hardly affected by osteoarthritis. Thus, ultimately, atlantoaxial movements including atlantoaxial rotation are markedly limited by osteoarthritis of the atlanto-odontoid joint. However, there is still potential for movement in the lateral atlantoaxial joints, as they remain relatively free of degenerative change. The vulnerability of the atlantoaxial segment is further increased by markedly limited rotation below the axis vertebra due to severe facet-joint degeneration. As a consequence, a relatively low-energy trauma to the lateral part of the face, for instance by a fall, will induce forced atlantoaxial rotation. This, with the marked limitation of movement at the atlanto-odontoid joint, will produce a torque force at the base of the odontoid process leading to a Type II fracture.

Aged↗