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C1-C2 posterior cervical fusion: long-term evaluation of results and efficacy.

Posterior wiring techniques are the most commonly used methods of achieving C1-C2 arthrodesis. Recently, transarticular screw fixation and interlaminar clamping have been advocated to achieve more secure fixation. A retrospective review of patients undergoing C1-C2 fusion for nonneoplastic disease was undertaken at the University of Toronto Hospital, with the aim of determining the long-term outcome of the selected procedures. Thirty-two patients underwent 36 procedures from 1986 to 1992, with a mean follow-up of 4.7 +/- 2.2 years (range, 2.0-8.0 yr). The most common disease processes were odontoid fracture (18 patients), transverse atlantal ligament injury (5 patients), os odontoideum (5 patients), and rheumatoid C1-C2 instability (3 patients). Thirty-one Gallie fusions, one Brooks-Jenkins fusion, two transarticular screw fusions, and two Halifax clamp applications were performed. Six (19%) of Gallie/Brooks-Jenkins fusions failed. These occurred with os odontoideum (three patients), Type II odontoid fracture (two patients), and transverse atlantal ligament injury (one patient). All transarticular screw and Halifax clamp procedures resulted in successful fusions. Two procedures (6%) resulted in new neurological deficit; both of these patients underwent posterior wiring for os odontoideum. This study suggests that Type II odontoid fractures may be successfully managed by a posterior wiring technique alone. Rheumatoid C1-C2 instability may be managed by posterior wiring supplemented with halo immobilization. Transarticular screw fixation has several potential advantages as a technique for C1-C2 arthrodesis and, in particular, may be appropriate for os odontoideum that had a high failure rate (75%) with conventional posterior wiring, even when this was supplemented with halo bracing.

Adolescent↗

Hydatid cyst of the craniocervical junction: case report.

OBJECTIVE AND IMPORTANCE: Although rare in developed countries, hydatid disease is a serious parasitic infection in endemic areas. Spinal disease most commonly involves the thoracic region, and involvement of the upper cervical spine is extremely rare. In this report, a case of hydatid disease involving the craniocervical junction is presented, along with a review of the literature. CLINICAL PRESENTATION: A 44-year-old man presented with the complaint of neck pain. The results of his physical and neurological examinations were within normal ranges, except for pain exacerbated by neck motion and spasm of the cervical musculature. Magnetic resonance imaging demonstrated a cystic lesion involving the odontoid process and body of C1 and C2, with thin and regular cyst walls and cyst contents similar in intensity to that of cerebrospinal fluid. The results of serological tests performed with the suspected diagnosis of hydatid disease were positive. INTERVENTION: The patient initially underwent surgery to provide stabilization of the craniocervical junction, using autogenous bone graft and sublaminar wiring from the occiput to C3 via a posterior approach. The cyst was approached via a transoral route, using a U-shaped pharyngeal incision. There were no neurological deficits after surgery. Postoperative magnetic resonance imaging scans confirmed complete excision of the cyst, and the patient was discharged on the 12th postoperative day. He received six cycles of albendazole treatment, each consisting of 28 days with an intervening drug-free period of 2 weeks. Magnetic resonance imaging scans performed 1 year after surgery revealed the patient was still disease-free. CONCLUSION: Hydatid disease should be considered in the differential diagnosis of spinal cord compression, especially in endemic areas. Although the chance of obtaining a cure is unlikely, radical surgery coupled with antihelminthic therapy seems to provide long-lasting relief.

Adult↗

[Surgical treatment of atlanto-axial subluxation by transoropharyngeal approach. Report of a case].

A case of atlanto-axial subluxation in a 17 year old boy with rheumatic disease is reported. The subluxation could not be reduced by cervical traction. Posterior fixation with acrilic and wire was unable to prevent the appearance of signs of spinal cord compression. The odontoid process was removed through a transoral approach leading to neurologic recovery. Treatment of atlanto-axial subluxation is discussed, emphasis being given to the indications for anterior descompression.

Adolescent↗

Spinal compression due to atlantal vertebral malformation in two African lions (Panthera leo).

Two young (14-mo-old and 6-mo-old), unrelated, male African lions (Panthera leo) were presented to the Veterinary Teaching Hospitals of Oklahoma State University and Kansas State University with progressive ambulatory difficulty. In both cases, limited neurologic evaluation demonstrated pelvic limb paresis and ataxia with conscious proprioceptive deficits. Spinal imaging showed nearly identical lesions in both cases. Radiography and myelography demonstrated cervical stenosis secondary to atlantal (C1) malformation producing a dorsoventral deformity of the laminar arch with atlantoaxial spinal cord compression between the ventrally displaced laminar arch of the atlas and the underlying odontoid process of C2. Computed tomography of the atlanto-axial junction confirmed cervical stenosis and cord compression, showing flattening of the spinal cord between the laminar arch of C1 and the dens of C2. Decompressive surgery consisting of dorsal laminectomy of C1 was performed. Each lion demonstrated progressive improvement of neurologic status to recovery of normal ambulation after surgical intervention. Neurologic disease in large captive felids is rare; atlanto-axial spondylomyelopathy has not been reported previously.

Animals↗

Occipitocervical stabilization for myelopathy in patients with rheumatoid arthritis. Implications of not bone-grafting.

BACKGROUND: Approximately 0.9 percent of the white adult population of the United States and 1.1 percent of the adult population in Europe are affected by seropositive rheumatoid arthritis. As many as 10 percent of those patients may need an operation for atlantoaxial subluxation. Severe instability, especially when associated with vertical subluxation of the odontoid process, can result in progressive cervical myelopathy. Typically, occipitocervical fixation has been performed for these patients with use of autograft bone to achieve long-term stability through a solid fusion. Harvesting the bone graft increases the operative risk to the patient and may result in increased morbidity. In our experience, patients who have had no clear radiographic evidence of fusion following use of occipitocervical instrumentation seemed to have done as well as those who have had obvious fusion. One assumption is that the clinical improvement might be attributable simply to stabilization of the joint rather than to osseous fusion. A longitudinal study was performed on patients with rheumatoid arthritis who required an operation because of craniocervical or upper cervical instability. METHODS: The results of clinical, radiographic, functional, and self-evaluations were studied to determine the efficacy of treatment and to compare the outcomes of bone-grafting with those of procedures done without bone-grafting in a group of 150 patients who underwent posterior occipitocervical stabilization with use of a contoured metal implant (a Ransford loop) that was affixed by sublaminar wires. Internal fixation was performed in 120 patients without bone-grafting and in thirty patients with use of autogenous bone-grafting. Preoperatively, 23 percent (thirty-five) of the 150 patients had mild neurological involvement (class II, according to the system of Ranawat et al.), 45 percent (sixty-eight) had objective findings of weakness and long-tract signs but were able to walk (class III-A), and 29 percent (forty-three) were quadriparetic and unable to walk (class III-B). The age of the patients at the time of the operation ranged from twelve to eighty-three years (mean, sixty-two years). RESULTS: There were significant improvements in postoperative Ranawat classes at all time-periods (range, p < 0.00005 to p = 0.0066) and in patient ratings of neck pain (range, p < 0.00005 to p = 0.0044) compared with preoperative scores. With the numbers available, there were no significant differences between the patients managed with a graft and those managed without grafting with respect to survival after the operation, Ranawat class, head or neck-pain rating, presence of subaxial abnormalities, radiographic craniovertebral motion, or vertical subluxation. Overall mortality at one month was 10 percent (fifteen of 150), although this value varied directly with the degree of preoperative disability. A second cervical spine operation was required in 11 percent (sixteen) of the 150 patients. CONCLUSIONS: While patients who have rheumatoid disease with anterior atlantoaxial subluxation should be treated with posterior atlantoaxial arthrodesis with use of bone-grafting and internal fixation, we believe that those who present with vertical instability and multi-level involvement can be treated with posterior occipitocervical stabilization with use of a contoured occipitocervical loop and sublaminar wire fixation without bone-grafting. Furthermore, we believe that the use of preoperative traction, bone cement, or a postoperative halo vest is unnecessary. Avoiding the harvesting of autogenous bone for grafting reduced the morbidity of this operation without compromising the outcome in these already sick patients.

Adolescent↗

Spinal instrumentation for unstable C1-2 injury.

Seventeen patients with unstable C1-2 injuries were treated between 1990 and 1997. Various methods of instrumentation surgery were performed in 16 patients, excluding a case of atlantoaxial rotatory fixation. Posterior stabilization was carried out in 14 cases using Halifax interlaminar clamp, Sof'wire or Danek cable, or more recently, transarticular screws. Transodontoid anterior screw fixation was performed in four cases of odontoid process fractures, with posterior instrumentation in two cases because of malunion. Rigid internal fixation by instrumentation surgery for the unstable C1-2 injury avoids long-term application of a Halo brace and facilitates early rehabilitation. However, the procedure is technically demanding with the risk of neural and vascular injuries, particularly with posterior screw fixation. Sagittal reconstruction of thin-sliced computed tomography scans at the C1-2 region, neuronavigator, and intraoperative fluoroscopy are essential to allow preoperative surgical planning and intraoperative guidance.

Adolescent↗

Pre- and postoperative MR imaging of the craniocervical junction in rheumatoid arthritis.

Ten patients with severe chronic rheumatoid arthritis with atlantoaxial subluxation were examined with conventional radiography and MR imaging of the cervical spine before and at an average of 6 months after posterior occipitocervical fusion. Periodontoid pannus formation was revealed by MR preoperatively in nine patients, all with mobile horizontal atlantoaxial subluxation. Compression of the medulla and/or upper cervical cord, due to subluxation and periodontoid pannus bulging into the spinal canal, was seen in seven patients. After the stabilizing surgery the periodontoid pannus had decreased in size in all patients with preoperative pannus. This reduction in the pannus seems to be the result of the atlantoaxial immobility achieved by the posterior fusion. Postoperatively, three patients had some remaining compression of the medulla and/or cord secondary to immobile subluxation, while the pannus posterior to the odontoid process had disappeared. Artifacts from the surgical stainless steel fixation material were confined to the posterior part of the neck on short TR/short TE MR images and did not interfere with the evaluation of the periodontoid region and the anterior part of the medulla/cervical cord. We found that flexion and extension lateral radiographs, combined with sagittal short TR/short TE MR images in the neutral position, enable preoperative evaluation of patients with rheumatoid arthritis in the cervical spine. Postoperative MR should be performed only if there are residual or new symptoms.

Aged↗

Pathogenesis, dynamics, and management of os odontoideum.

Os odontoideum is an uncommon craniovertebral junction (CVJ) abnormality that exists as a separate ossicle apart from a hypoplastic dens. It usually moves with the clivus or the anterior arch of C-1 (dystopic) or rarely with the dens (orthotopic). Its genesis and natural history have been debated, and its proper treatment remains uncertain. Two hundred and sixty patients, with symptomatic os odontoideum, were evaluated by the author over a 20-year period; the author performed surgery in 134 of these patients. In a prospective study the author evaluated the early childhood history of trauma, the dynamic studies of motion, and the effects of traction by using pleuridirectional tomography, computerized tomography (CT), CT myelography and magnetic resonance (MR) imaging. Operative findings were documented. Early childhood trauma to the CVJ was recorded in 74 patients, in 30 of whom normal odontoid processes were documented at initial examination prior to the patient reaching age 4 years. Acute neurological deterioration following trauma occurred in 63 of 134 patients. Symptoms were insidious in 71 of 134 patients. In six patients, who presented with acute neurological deterioration after trauma and in whom an abnormal spinal cord signal in the cervicomedullary junction was demonstrated on MR imaging, normal CVJ motion dynamics were shown. Motion dynamics varied and were unique to each patient. Irreducible ventral CVJ disease causing cervicomedullary compromise occurred in 28 patients in whom a transpharyngeal ventral decompressive procedure was necessitated. During the transoral operation, the transverse portion of the cruciate ligament was found to be located anterior to the axis body. All patients required dorsal CVJ arthrodesis, which, in 46, was limited to the C1-2 segment. Instability at the C1-2 joints was always multidirectional, as demonstrated on preoperative neuroimaging studies as well as at operation. Sixteen patients presented after completed primary C1-2 dorsal fusion and with worsening deficits. They improved when the range of the fusion was extended to the occiput or if the ventrally located lesion was excised. Os odontoideum is associated with early childhood trauma and is an acquired phenomenon. The presence of abnormal motion dynamics necessitates surgical intervention as do associated neurological deficits. Asymptomatic patients in whom os odontoideum is incidentally discovered and in whom no abnormal motion dynamics are demonstrated should be followed closely.

Journal Article↗

Intraoperative magnetic resonance imaging-augmented transoral resection of axial disease.

OBJECT: Because transoral decompression of the cervicomedullary junction is compromised by a narrow surgical corridor, the adequacy of decompression/resection may be difficult to determine. This is problematic as spinal hardware may obscure postoperative radiological assessment, or the patient may require reoperation. The authors report three patients in whom high-field intraoperative magnetic resonance (MR) images were acquired at various stages during the transoral resection of C-2 lesions causing craniocervical junction compression. METHODS: In all three patients the lesions involved the cervicomedullary junction: one case each of plasmacytoma and metastatic breast carcinoma involving the odontoid process and C-2 vertebral body, and one case of basilar invagination with a Chiari type I malformation. All three patients presented with progressive myelopathy. Surgery-planning MR imaging studies, performed after the induction of anesthesia, demonstrated the lesion and its relationship to the planned surgical corridor. Transoral exposure was achieved through placement of a Crockard retractor system. In one case the soft palate was divided. Interdissection MR imaging revealed that adequate decompression had been achieved in all cases. In the two patients with carcinoma, posterior instrumentation was placed to achieve spinal stabilization. Planned suboccipital decompression and fixation was averted in the third case because MR imaging demonstrated that excellent decompression had been achieved. CONCLUSIONS: Intraoperatively acquired MR images were instrumental in determining the adequacy of surgical decompression. In one patient the MR images changed the planned surgical procedure. Importantly, the acquisition of intraoperative MR images did not adversely affect operative time or neurosurgical techniques, including the instrumentation procedure.

Aged↗

Symptomatic atlantoaxial instability in Down syndrome.

OBJECT: The aim of this study was to audit the treatment of symptomatic atlantoaxial instability in Down syndrome and to assess factors associated with fusion failure in this group of patients. METHODS: The authors reviewed the cases of 12 children with Down syndrome presenting with symptomatic atlantoaxial instability who underwent surgery for internal fixation and fusion. A review of clinical histories, radiological investigations, and details of operative interventions was also performed. The mode of presentation was acute spinal cord injury (five cases), progressive myelopathy (four cases), and neck pain or stiffness (three cases). The atlantodental interval ranged from 5 to 13 mm. The posterior atlantodental interval at the C-1 level was 9.5 mm (range 6-11 mm). In 10 patients an os odontoideum was present. Translocation of the odontoid process occurred in one patient, and occipitoatlantal instability was also identified in two cases. Twenty-four operations were performed in the 12 patients. A transoral odontoidectomy was required in four children. Successful fusion was demonstrated in seven patients at the first operation. Three of the five patients with acute cord injury made significant functional recovery and were left with no or mild disability. CONCLUSIONS: Additional bone abnormalities at the CVJ are common in the Down syndrome population. Young age at the time of fusion and multiple osseous anomalies pose a higher risk factor in fusion failure. The authors recommend an aggressive surgical approach for management of symptomatic cases of CVJ instability.

Adolescent↗

Bilateral sagittal split mandibular osteotomies as an adjunct to the transoral approach to the anterior craniovertebral junction. Technical note.

Transoral approaches are used to expose the craniovertebral junction anteriorly. In patients in whom there is limited mandibular excursion, the placement of retractors and/or surgical instruments is difficult, and midline "stairstep split mandibulotomy" has been advocated as an adjunctive procedure. Although effective, this approach requires external splitting of the lip as well as median glossotomy or a lateral mucosal incision. The purpose of this study was to show that bilateral sagittal split mandibular osteotomies (BSSMOs), which are used in orthognathic surgery, represent a safer and more effective alternative to the stairstep split mandibulotomy when performed as an adjunct to the transoral approach because all incisions are intraoral and the plane of retraction is rostrocaudal instead of lateral. Hospital records and radiographic files of four patients who underwent BSSMO/transoral approach for odontoidectomy between 1994 and 1997 were reviewed retrospectively. There were three women and one boy (mean age 37.8 years, range 11-68 years). Predisposing conditions included rheumatoid arthritis (two patients), Klippel-Feil syndrome (one patient), and congenital occipitocervical instability (one patient). Jaw mobility was limited in all patients. In addition, one patient had macroglossia, another micrognathia, and another retrognathia. The BSSMO provided excellent exposure for resection of the odontoid process, as verified on follow-up magnetic resonance imaging or computerized tomography studies obtained in all patients. All mandibles were rigidly fixed by placing anterior mandibular border titanium plates and unicortical screws, and there was no incidence of nonunion or of lingual or inferior alveolar nerve injuries. The mean follow-up period was 26 months. The BSSMO is an excellent, less invasive adjunct to the transoral approach in patients with limited jaw mobility.

Adolescent↗

Transoral resection of axial lesions augmented by intraoperative magnetic resonance imaging. Report of three cases.

Transoral decompression of the cervicomedullary junction may be compromised by a narrow corridor in which surgery is performed, and thus the adequacy of surgical decompression/resection may be difficult to determine. This is problematic as the presence of spinal instrumentation may obscure the accuracy of postoperative radiological assessment, or the patient may require reoperation. The authors describe three patients in whom high-field intraoperative magnetic resonance (MR) images were acquired at various stages during the transoral resection of C-2 disease that had caused craniocervical junction compression. All three patients harbored different lesions involving the cervicomedullary junction: one each of plasmacytoma and metastatic breast carcinoma involving the odontoid process and C-2 vertebral body, and basilar invagination with a Chiari I malformation. All patients presented with progressive myelopathy. Surgical planning MR imaging studies performed after the induction of anesthesia demonstrated the lesion and its relationship to the planned surgical corridor. Transoral exposure was achieved through placement of a Crockard retractor system. In one case the soft palate was divided. Interdissection MR imaging revealed that adequate decompression had been achieved in all cases. The two patients with carcinoma required placement of posterior instrumentation for stabilization. Planned suboccipital decompression and placement of instrumentation were averted in the third case as the intraoperative MR images demonstrated that excellent decompression had been achieved. Intraoperatively acquired MR images were instrumental in determining the adequacy of the decompressive surgery. In one of the three cases, examination of the images led the authors to change the planned surgical procedure. Importantly, the acquisition of intraoperative MR images did not adversely affect operating time or neurosurgical techniques, including instrumentation requirements.

Aged↗

Posterior atlantoaxial dislocation without fracture. Case report.

Posterior dislocation of the atlas onto the axis without related fracture of the odontoid process is a very rare traumatic condition of which five cases have been previously reported. The authors present a sixth case in which management was different from the others. The patient was successfully treated by open reduction of the dislocation and C1-2 transarticular screw fixation. The rarity of the lesion, the differences in diagnostic studies, and the successful treatment by safe intraoperative reduction and fixation are factors of interest in this case.

Atlanto-Axial Joint↗

Anomalous vertebral artery at the craniovertebral junction in a patient with Down syndrome. Case report.

The authors report a case of a patient with Down syndrome in whom the abnormal course of the right vertebral artery (VA) at the craniovertebral junction (CVJ) was accurately demonstrated on three-dimensional (3D) computerized tomography (CT) angiography. The patient was a 5-year-old boy, who developed severe myelopathy. Bone abnormalities were also present at the CVJ, including atlantoaxial and occipitoatlantal instabilities, a hypoplastic odontoid process, and ossiculum terminale. Three-dimensional CT angiography revealed that the right VA was duplicated after emerging from the C-2 transverse foramen. One half of the duplication, an artery that was as large as the left VA, turned posteromedially and entered the spinal canal between C-1 and C-2. The other half, a very small artery, ran as usual and passed through the C-1 transverse foramen. The authors performed an occipitocervical posterior fusion and a C-1 laminectomy. Intraoperatively the course of the anomalous VA was identified on Doppler ultrasonography, and the surgical approach and bone excision were undertaken carefully to avoid VA injury. Postoperatively, resolution of myelopathy was marked. In the surgical treatment of patients with Down syndrome, surgeons should consider the possibility that a VA anomaly is present at the CVJ. With preoperative 3D CT angiography, the anomalous VA can be identified precisely and the possible risk of intraoperative VA injury predetermined.

Angiography↗

Multiple fractures of the axis.

Multiple fractures of the axis are not common lesions. A retrospective study was performed to identify the different fracture patterns and to analyze the incidence of these injuries and their long-term behavior. The medical records of 674 consecutive patients with fractures of the cervical spine were reviewed. Nine (1%) of 674 patients (6 men and 3 women) had multiple fractures of the axis. Mean patient age was 48 years. The most common lesion was a combination of traumatic spondylolisthesis with either an odontoid process or a teardrop fracture of the axis body. All patients were treated conservatively with an excellent or good outcome at mean 12-year follow-up (range: 2-18 years). Computed tomography was the imaging modality of choice for the correct diagnosis of these rare lesions.

Adult↗

[One-stage operative treatment of atlanto-axial instability with stenosis of lower cervical level of spinal canal].

To cure patients suffering from atlanto-axial instability following old fracture of odontoid process concomitant with stenosis of lower end of cervical spinal canal, a new operative method was designed. It included atlanto-axial fusion by Gallie technique and resection of right half of the laminae of C3-C7 spine at one stage. A female of 63 years old was treated. She was admitted with neck pain and numbness of the upper and lower limbs. A history of neck injury was noted in enquiry. In physical examination showed the sensation of pain of the upper limbs was decreased and the muscle power of the upper and lower limbs ranged from III degree to IV degree. The X-ray film and MRI suggested that there was instability of the atlanto-axial joint with stenosis of 4th-6th cervical spinal canal. The operation was satisfactory. After operation, the patient was followed up for 11 months. The physical examination indicated that sensation of the upper limbs had recovered to normal and the muscle power of the upper limbs reached IV degree and that the lower limbs reached V degree and X-ray showed bony fusion of the atlanto-axial joint. The conclusions were: 1. The stability of atlanto-axial joint was reconstructed with expanding of the spinal canal at the same time. 2. The duration, risk and cost of the therapy were reduced, and maintenance of the stability of the cervical spine throughout whole period of treatment was recommended.

Atlanto-Axial Joint↗

Traumatic induced total myelomalacia of the cervical spinal cord associated with a space-occupying subdural hematoma.

We report the case of a 20-year-old male driver who suffered from a trauma to the cervical vertebral column in a head-on collision with a tree. The injuries included subluxation of the 2nd and 3rd cervical vertebrae and fracture of the odontoid process of the axis with ventrally directed displacement of the proximal fragment and dorsally directed displacement of the distal fragment. Already at admission to hospital a space-occupying spinal subdural hematoma was diagnosed. Clinically, paraplegia was diagnosed with progressive loss of consciousness. Pneumonia led to death 40 days after the accident. Autopsy disclosed a total myelomalacia of the cervical spinal cord obviously resulting from an ischemia caused by a traumatic lesion of the dorsal truncus arteriosus spinalis as well as a compression by the spinal subdural hematoma.

Adult↗

[Halo-traction efficacy in surgery on the cervical spine].

The paper deals with the use of a halo-apparatus in lesions and diseases of the cervical vertebra. The halo-apparatus was used in 70 patients. It was most commonly employed in lesions of the upper cervical vertebra, such as fractures of the odontoid process and C2 vertebral arches. Analyzing the clinical findings showed halo-traction to be highly effective.

Adolescent↗