Pyogenic osteomyelitis of the odontoid process: single stage decompression and fusion

STUDY DESIGN

A case report.

OBJECTIVES

To document our experience with single stage decompression and fixation in the treatment of pyogenic osteomyelitis of the odontoid process.

SUMMARY OF BACKGROUND DATA

Although several investigators have reported a handful of these unusual cases, up until now, there have been no studies concerning a single stage solution in the surgical treatment of this pathology.

METHODS

Three patients with osteomyelitis of the odontoid process caused by Staphylococcus aureus underwent surgical treatment in single sessions (transoral decompression combined with posterior fusion as the second step of the operation). Following surgery, the patients underwent a 6-week antibiotic course administered both intravenously and orally. Furthermore, we recommended the use of a hard cervical collar for 8 weeks together with isometric rehabilitation of the cervical muscles. Currently, follow-up results are available for two patients.

RESULTS

On examination at 3 months, 6 months, and 1 year after the surgery, both patients had completely recovered with no neurologic deficit. Plain radiographs showed complete posterior fusion after 6 and 12 months, respectively.

CONCLUSIONS

We emphasize the advantages of our method in comparison with nonoperative treatment or multisession surgery. The single stage surgical solution led to a shortening of hospitalization time with no need for halo bracing, to excellent results with respect to C-spine stability and to better compliance from the patients.

[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.

Anterior screw fixation in type II odontoid fractures: is there a difference in outcome between age groups?

OBJECTIVE

Optimal treatment of elderly patients with Type II odontoid fractures is controversial. Suggestions vary between conservative management and different types of early surgery. Recent data confirm that early surgery may be warranted because conservative treatment has a high rate of failure in the elderly.

METHODS

We performed a case-control study of 27 patients with Type II odontoid fracture who were treated with anterior odontoid double-screw fixation at our institution. The aim of the study was to determine whether patients aged 70 years or older have a less favorable outcome than younger patients with this operative technique. Cases were defined as patients with Type II odontoid fracture aged 70 years or older. All patients younger than 70 years served as controls.

RESULTS

There were 15 patients aged 70 years or older (Group 1) and 12 patients younger than 70 years of age (Group 2). Mean follow-up was 16.6 months. Mean interval between fracture and surgery was 10 days. All patients were treated with anterior odontoid screw fixation by use of two compression screws. Fusion rates were 73% in Group 1 and 75% in Group 2. Additional dorsal stabilization was performed in 13% of cases in Group 1 and 17% of cases in Group 2. Complications occurred in 20% of cases in Group 1 and 8% of cases in Group 2. The only death occurred in Group 1, leading to 7% mortality in this group. Neurological status at admission and after treatment was similar in both groups. Statistical analysis did not reveal significant differences between groups for the factors studied.

CONCLUSION

Outcome after anterior odontoid screw fixation is not affected by patient age. Slightly higher rates of medical complications did not reach statistical significance. Because conservative management of odontoid fractures in the elderly has a high rate of failure, anterior stabilization for Type II odontoid fractures can be recommended.

A new table-fixed retractor for anterior odontoid screw fixation: technical note

The authors describe a unique retraction device adapted for anterior odontoid screw placement. A rigidly fixed tubular retractor system obviates the need for dissecting the longus colli muscles as well as for excessive retraction of the trachea, esophagus, and recurrent laryngeal nerve. The proper trajectory for screw placement can be determined by fine manipulation of the retractor as determined by biplanar fluoroscopy. The retractor is then rigidly fixed in position. The tubular corridor permits the odontoid screw to be placed in the usual fashion.

A clinical case of endoscopically assisted anterior screw fixation for the type II odontoid fracture

STUDY DESIGN

A clinical case using a new surgical technique is reported.

OBJECTIVE

To report for the first time an endoscopically assisted anterior screw fixation for the Type II odontoid fracture.

SUMMARY OF BACKGROUND DATA

Recently, many endoscopically assisted surgeries have been performed for various spinal surgery because of its minimally invasive character. However, the anterior retropharyngeal approach to the upper cervical spine using endoscopy has not been reported.

METHODS

A 76-year-old man was operatively managed for a Type II odontoid fracture. The operation was performed under immobilization of cervical spine using a halo vest apparatus. A skin incision 2 cm long was made on the medial border of the right sternocleidomastoid muscle at the C5-C6 intervertebral level. Blunt dissection between the neurovascular bundle laterally and the trachea and esophagus medially was performed. A processed polyethylene syringe (volume, 10 mL) was used as the tubular retractor. This retractor kept the minimum but sufficient space for the screw fixation and avoided esophageal complication. Using a cannulated screw system, a cancellous screw was inserted from the anteroinferior edge of the C2 vertebral body to the tip of the odontoid process. The drilling and the screwing process was monitored by a two-dimensional image intensifier. The entry point was monitored by endoscopy to avoid soft tissue involvement as well.

RESULTS

The operation was completed without any soft tissue complications such as esophageal injury. The blood loss was 30 mL. The procedure resulted in nonunion, partially because of patient's old age or an entry point 2 mm above the anterior caudal margin of the C2 body retrospectively.

CONCLUSIONS

Although the reported odontoid fracture ended in nonunion, the authors believe their modification of the approach using an endoscope made anterior screw fixation for the odontoid fracture safer and less invasive than the original anterior retropharyngeal approach.

Posterior atlanto-axial fusion with the Olerud Cervical Fixation System for odontoid fractures and C1-C2 instability in rheumatoid arthritis

In posterior C1-C2 fusion, traditional wire fixation gives poor stability. The bone quality is often insufficient to provide the competent structural bone graft that is required, and the introduction of sublaminar wires is somewhat dangerous. The stability is markedly improved by adding transarticular screws, but the drawbacks of structural bone graft and sublaminar wires remain. The C1 claw of the Olerud Cervical Fixation System improves C1-C2 fixation without relying on structural bone graft or compromising the spinal canal. The aim of this study was to evaluate radiological healing and possible complications in a consecutive series of C1-C2 fusions from our department operated with the C1 claw device. Twenty-six patients (14 women) with a mean age of 73 (range 37-93) years were included. The diagnoses were odontoid fracture in 18 patients, rheumatoid instability in 6, and odontoid non-union and os odontoideum in 1 each. The patients were followed clinically and with plain radiographs for an average of 15 (range 3-27) months. There were no neurological or vascular complications, and no secondary displacements or reoperations in the series. Twenty patients followed for 6-27 months were radiographically healed. Six patients died from unrelated causes 1-38 months postoperatively. Three of these patients had no radiographs later than the postoperative control, one had a healed odontoid fracture but resorbed bone graft at 8 months, while the remaining two patients were not healed, but showed no signs of healing disturbance at the time of death. On the basis of the findings of this study, posterior C1-C2 fusion with the Olerud Cervical Fixation System seems promising. No serious complications related to the surgical procedure were encountered. The stability of the implant obviates the use of a solid bone block as a graft and still allows a high frequency of fusion healing.

Fatal instability following "odontoid sparing" transoral decompression of a periodontoid pseudotumour

Pseudotumour of the craniovertebral junction is an uncommon cause of high cervical myelopathy in the elderly. The anterior transoral approach is the preferred means of accessing these lesions. An "odontoid sparing" transoral approach, in which there is only minimal bone removal, is thought to preserve stability of the craniovertebral junction, obviating the need for posterior stabilisation. This report is of an 82 year old man who developed fatal atlanto-axial instability following an odontoid sparing transoral resection of a pseudotumour. This complication has not previously been described and its occurrence has important implications for the surgical management of this condition.

Biomechanical testing of posterior atlantoaxial fixation techniques

STUDY DESIGN

An in vitro biomechanical study of C1-C2 posterior fusion techniques was conducted using a cadaveric model.

OBJECTIVE

To investigate and compare the acute stability afforded by a novel rod-based construct that uses direct polyaxial screw fixation to C1 and C2 with contemporary transarticular screw and wire techniques.

SUMMARY AND BACKGROUND DATA

Acute stability of the atlantoaxial complex is required to achieve bony consolidation. Various forms of posterior wiring were the first standardized procedures advocated to achieve C1-C2 fixation, but because of insufficient construct stability, these techniques have been coupled with transarticular screw fixation. Significant technical difficulties, however, including the possibility of neurovascular compromise during implantation are associated with transarticular screw placement. A novel technique that uses direct polyaxial screw fixation to C1 and C2 and bilateral longitudinal rods was developed recently. However, there are no published reports detailing the biomechanical characteristics of this new construct.

METHODS

In this study, 10 fresh-frozen human cadaveric cervical spines with occiput (C0-C4) were used. Osteoligamentous specimens were tested in their intact condition after destabilization via odontoidectomy, and after two different Gallie wiring techniques. Each specimen was assigned to one of the two screw fixation groups. Five specimens were implanted with the polyaxial screw-rod construct and tested. The remaining five specimens were tested after application of bilateral C1-C2 transarticular screws with Gallie wiring (Magerl-Gallie technique). Pure-moment loading, up to 1.5 Nm in flexion and extension, right and left lateral bending and right and left axial rotation, was applied to the occiput, and relative intervertebral rotations were determined using stereophotogrammetry (motion analysis system). Range of motion data for all fixation scenarios were normalized to the destabilized case, and statistical analysis was performed using one-way analysis of variance with Fisher's least significant difference PLSD post hoc test for multiple comparisons.

RESULTS

The data indicate that destabilization via odontoidectomy significantly increased C1-C2 motion. Both screw techniques significantly decreased motion, as compared with both Gallie wiring methods in lateral bending and axial rotation (P < 0.02 for all) and tended toward reduced motion in flexion-extension. There was no statistically significant difference between the two screw techniques.

CONCLUSIONS

The results clearly indicate the screw-rod system's equivalence in reducing relative atlantoaxial motion in a severely destabilized upper cervical spine, as compared with the transarticular screw-wiring construct. These findings mirror the previously reported clinical results attained using this new screw-rod construct. Thus, the decision to use either screw construct should be based on safety considerations rather than acute stability.

Late recovery following spinal cord injury. Case report and review of the literature

The authors of this prospective, single-case study evaluated the potential for functional recovery from chronic spinal cord injury (SCI). The patient was motor complete with minimal and transient sensory perception in the left hemibody. His condition was classified as C-2 American Spinal Injury Association (ASIA) Grade A and he had experienced no substantial recovery in the first 5 years after traumatic SCI. Clinical experience and evidence from the scientific literature suggest that further recovery would not take place. When the study began in 1999, the patient was tetraplegic and unable to breathe without assisted ventilation; his condition classification persisted as C-2 ASIA Grade A. Magnetic resonance imaging revealed severe injury at the C-2 level that had left a central fluid-filled cyst surrounded by a narrow donutlike rim of white matter. Five years after the injury a program known as "activity-based recovery" was instituted. The hypothesis was that patterned neural activity might stimulate the central nervous system to become more functional, as it does during development. Over a 3-year period (5-8 years after injury), the patient's condition improved from ASIA Grade A to ASIA Grade C, an improvement of two ASIA grades. Motor scores improved from 0/100 to 20/100, and sensory scores rose from 5-7/112 to 58-77/112. Using electromyography, the authors documented voluntary control over important muscle groups, including the right hemidiaphragm (C3-5), extensor carpi radialis (C-6), and vastus medialis (L2-4). Reversal of osteoporosis and an increase in muscle mass was associated with this recovery. Moreover, spasticity decreased, the incidence of medical complications fell dramatically, and the incidence of infections and use of antibiotic medications was reduced by over 90%. These improvements occurred despite the fact that less than 25 mm2 of tissue (approximately 25%) of the outer cord (presumably white matter) had survived at the injury level. The primary novelty of this report is the demonstration that substantial recovery of function (two ASIA grades) is possible in a patient with severe C-2 ASIA Grade A injury, long after the initial SCI. Less severely injured (lower injury level, clinically incomplete lesions) individuals might achieve even more meaningful recovery. The role of patterned neural activity in regeneration and recovery of function after SCI therefore appears a fruitful area for future investigation.

[Management of odontoid fractures using anterior screw fixation: analysis of 15 cases]

A retrospective analysis of the results of 15 patients with odontoid fractures type II P and II N, according to Roy-Camille's classification is presented. They were operated on by an anterior approach and direct fixation of the odontoid process through a screw. There were 13 men and 2 women, the age ranging from 14 to 74 years. The follow up period was from 6 to 36 months (mean 20 months). There was only one complication related to the surgical technique: one screw was misplaced and it was necessary another surgery to replace it. There were no deaths in this series. There were no screw breakdown and the fusion rate was 94%. We propose, based on this study, that the classification of Roy-Camille for odontoid fractures should be always used, since it proposes one surgical approach for each type of fracture. The results of this series show that this technique is useful and has advantages over another modalities of treatment. The correct diagnosis of the type of fracture and an appropriate selection of patients are the main elements to achieve good results.

[Primary osteosynthesis of the odontoid process: a multicenter study]

PURPOSE OF THE STUDY

Direct osteosynthesis is a method of choice for the treatment of odontoid process fractures. It is based on insertion, from the anterior approach, of one or two screws from the C2 body into the apex of the odontoid across the fracture line. The tensile action of screws results in compression of fragments and stabilization of the fracture. The aim of the study was to evaluate a group of patients treated by this method and to compare our results with those reported in the foreign literature.

MATERIAL

A total of 99 patients were treated by direct osteosynthesis of the odontoid in the departments involved in the study between 1994 and 2001.

METHODS

Patients indicated for this surgery were those with fractures of type II according to Anderson and D'Alonzo and those with type III fractures but only when the fracture line went across the articulation surfaces of C1-C2, when closed reduction was not possible or the patients were not indicated for halo fixation. Direct osteosynthesis was not applied to fractures with comminution at the base of the odontoid, irreducible fractures, odontoid fractures combined with dislocated fractures of the atlas or pathological fractures. Severe kyphosis of the cervical spine or a large thoracic cage was also regarded as a contraindication.

RESULTS

All the 99 patients were followed up from 3 up to 102 months, with an average of 28.5 months; only in seven patients, the follow-up period was shorter than 6 months. The most frequent subjective complaint was a painful operation wound. This usually resolved within two weeks of surgery. Except for four patients, alle were satisfied with the outcome. Type II fractures were diagnosed in 84 and type III fractures in 15 cases. A total of 174 screws were inserted into the odontoid processes of 99 patients. A single screw was used in 25 and two screws in 73 patients. In one case, three screws had to be inserted. Screw lenght ranged from 36 to 44 mm, diameter was 40.9 mm. Three months after surgery, X-ray examination, both in flexion and extension, did not reveal any instability in any of the patients. No morphological change in the C2-C3 intervertebral space was observed Of 92 (92.9%) paitents under longterm follow-up, 84 (91.3%) showed complete healing of the fracture, three died and five patients eventually developed pseudoarthrosis, which was due to a broken screw in three of them. This condition was treated by dorsal fixation of C1-C2 according to Magerl or by one of the dorsal cerclage techniques. The group was free of any perioperative complications related to the anterior approach or injury to nerve structures by screws.

DISCUSSION

The most frequent subjective complaint was a painful operation wound. Treatment of odontoid fractures varies according to the type of injury, bone quality and also practice at each department. Type II injuries are highly unstable and, because of the small fracture surface, their healing ability is much lower than in type III fractures. Previously, most of the patients with odontoid injuries were treated conservatively by immobilization in a plaster cast or a brace or, later, by a halo device. In the long term, however, they showed a high proportion of pseudoarthroses (10 to 100%). Direct osteosynthesis of the odontoid by screws permits the maintenance of rotation of the C1-C2 mobile segment. We followed the scheme of indications used abroad but did not perform osteosynthesis to correct pseudoarthrosis. The number of osteosyntheses healed (91.3%) was also in agreement with the literature data. Earlier, we used two screws for all types of fractures. Recently, we have preferred insertion of a single screw in type II and III fractures in narrow odontoids. In the later, there is no danger of rotational dislocation during screw insertion; to insert one screw from the centre of the C2 base is easy and speeds up the procedure. However, in displaced type II and type II T fractures, two screws are a necessity. Similarly to other authors, we recorded a slight limitation of cervical spine rotation in patients at long-term follow-up, particularly in elderly subjects with advanced osteochondrosis. No complications leading to deterioration of the patient's state were recorded.

CONCLUSIONS

Direct osteosynthesis is a method of choice for most of the type II and indicated cases of type III fractures of the odontoid process of the axis. This surgical procedure facilitates restoration of anatomical conditions of the spine and its immediate stability. Consequently, patients can be readily mobilized and rehabilitated.

Combined anterior and posterior approach for managing basilar invagination associated with type I Chiari malformation

Ventral brainstem compression is common in patients with basilar invagination associated with type I Chiari malformation. The aim of this study was to investigate the reliability of a combined one-session anterior-posterior surgical approach for these patients. Nine patients underwent transoral odontoidectomy, posterior foramen magnum decompression, occipitocervical fixation, and bone grafting. All but two patients had ventral and dorsal operations in one surgical sitting. One of these two individuals had previously undergone posterior decompressive surgery at another hospital, but his condition had deteriorated rapidly afterward. The mean follow-up time was 19 months (range, 14-30 months). There was no mortality and no significant morbidity in this series. All but one of the patients showed significant improvement in their symptoms. Chiari malformations have a surprisingly high association with basilar invagination, and patients may have symptoms in both conditions. If there is a marked anterior compression, anterior transoral and posterior decompression, fusion, and instrumentation is an optimal strategy for treating patients with basilar invagination associated with type I Chiari malformation.

Magnetic resonance imaging confirmation of resolution of periodontoid pannus formation following C1/C2 posterior transarticular screw fixation

Chronic odontoid fractures are considered unstable spinal lesions. Chronic instability in this region leads to the development of an inflammatory pannus, which can progress resulting in spinal cord compression radiographically and a myelopathy syndrome clinically. In this report we document three cases of reversal of pannus after C1/C2 transarticular screw fixation of an unstable odontoid fracture. Three patients were identified with chronic odontoid fractures and spinal cord compression due to periodontoid pannus formation. All patients presented with a progressive myelopathy syndrome. All patients underwent preoperative and postoperative magnetic resonance imaging (MRI) of the craniovertebral junction. C1/C2 transarticular screw fixation was performed for stabilization of C1/C2. Postoperatively there were no complications. Postoperative MRI at 6 months demonstrated resolution of the ventral pannus. Moreover, all patients exhibited improvement of preoperative neurological deficits. MRI is the imaging technique of choice for diagnosis and follow-up of patients with chronic odontoid fractures and ventral pannus. C1/C2 transarticular screw fixation provides a viable method for spinal stabilization in this region. In addition, stabilization can result in resolution of inflammatory pannus formation secondary to instability of the C1/C2 articulation.

Toxic epidermal necrolysis after phenytoin usage in a brain trauma patient

Toxic epidermal necrolysis is a drug-induced, rare, but life-threatening skin eruption. The main differential diagnoses are drug-induced erythema (hypersensitivity syndrome), acute graft-versus-host disease, staphylococcal scalded skin syndrome, and toxic shock syndrome. Because the therapy for toxic epidermal necrolysis and acute graft-versus-host disease differs largely from the others, it is necessary to make an accurate diagnosis. In addition to a detailed medical history, skin biopsy is mandatory because the skin eruptions are not always unequivocal. Discontinuation of the causing agent is crucial, and treatment in specialized intensive care units or burn units is supportive. Currently there is no specific treatment for toxic epidermal necrolysis. Advantages from corticosteroids, plasmapheresis, intravenous immunoglobulin, cyclophosphamide, cyclosporin, and N-acetylcysteine still remain to be established by controlled trials, or have failed to prove a benefit (thalidomide). The patient presented here demonstrates the difficulties in diagnosing toxic epidermal necrolysis in a critically ill patient. A short overview of the pathogenesis and the management of toxic epidermal necrolysis is provided.

Retro-odontoid pseudotumor in diffuse idiopathic skeletal hyperostosis

STUDY DESIGN

A rare case of retro-odontoid pseudotumor combined with diffuse idiopathic skeletal hyperostosis is presented.

OBJECTIVE

To discuss the pathomechanism of retro-odontoid pseudotumor in diffuse idiopathic skeletal hyperostosis.

SUMMARY OF BACKGROUND DATA

Reports describing craniovertebral manifestations of diffuse idiopathic skeletal hyperostosis are quite rare. Only two cases of an atlantoaxial subluxation and one case of an odontoid fracture have been reported. Myelopathy resulting from retro-odontoid pseudotumor combined with diffuse idiopathic skeletal hyperostosis has not been reported previously.

METHODS

A 74-year-old man presented with spastic tetraparesis caused by a retro-odontoid pseudotumor combined with diffuse idiopathic skeletal hyperostosis. Transoral removal of the extradural mass combined with a dorsal atlantoaxial fusion was performed using a titanium frame with sublaminar cable wiring.

RESULTS

Yellowish amorphous material extruded from between the odontoid process and the arch of C1 when the anterior capsule had been incised. The retro-odontoid mass was very firmly attached to the hypertrophied ligaments. The mass therefore had to be sharply dissected away to expose the dura. The histologic appearance of the mass consisted of poorly cell-degenerated ligament, fibrocartilage, and fibrin. There was a focal proliferation of small vessels, but no significant inflammatory component and no evidence of neoplasia. The ligaments appeared fibrillated, disintegrated, and fragmented. After surgery, the patient's neurologic function improved.

CONCLUSIONS

This is the first reported case of a retro-odontoid pseudotumor combined with diffuse idiopathic skeletal hyperostosis. The secondary transfer of mechanical stress to the atlantoaxial segment was presented as a pathomechanism underlying the formation of this retro-odontoid pseudotumor.

Biomechanical comparison of four anterior atlantoaxial plate systems

OBJECT

The optimum fixation method to achieve atlantoaxial fusion after resection of the odontoid process remains a matter of discussion. Anterior atlantoaxial plate fixation has been described by Harms as a fixation procedure to be performed after transoral odontoid resection. In recent biomechanical and clinical studies investigators have shown that this procedure is a good alternative to established posterior atlantoaxial fixation techniques, but they have also indicated the biomechanical disadvantages of the Harms plate design. Therefore, three new anterior atlantoaxial plate designs were developed. The purpose of this study was to compare these three newly designed plate systems biomechanically with that used in Harms anterior atlantoaxial plate fixation.

METHODS

Twenty-four human craniocervical cadaveric specimens were tested in flexion, extension, axial rotation, and lateral bending in a nonconstrained testing apparatus by using a nondestructive stiffness method. Three-dimensional displacement of C 1-2 was measured with an optical measurement system. Six different groups were examined: 1) control (24 specimens); 2) unstable (after odontoidectomy and dissection of the atlantoaxial ligaments; 24 specimens); 3) Harms (anterior atlantoaxial plate fixation according to Harms; six specimens); 4) subarticular atlantoaxial plate (SAAP; six specimens); 5) transpedicular atlantoaxial plate (TAAP; six specimens); and 6) subarticular atlantoaxial locking plate (SAALP; six specimens). Stiffness, range of motion, and neutral and elastic zones were determined. Compared with the Harms plate, stiffness was significantly higher when methods for placing the SAAP, TAAP, and SAALP devices were used (p < 0.05). Angular displacement of SAALPs was less than that demonstrated in any other group (p < 0.05). Stiffness values in any direction were significantly greater for the SAALP-fixed specimens than for the TAAP, SAAP, Harms, control, or unstable specimens (p < 0.05).

CONCLUSIONS

Experimentally, the SAAP, TAAP, and Harms plate achieved less stable fixation than the SAALP. Therefore, if transoral odontoid resection is performed, SAALP-fixed spines will provide significantly improved stability compared with previous fixation devices and methods. This may be a necessary prerequisite for a fast and uneventful osseous fusion even without additional posterior stabilization.

Endoscopic endonasal approach to the ventral cranio-cervical junction: anatomical study

OBJECTIVE

In order to develop an endoscopic endonasal approach to the ventral cranio-cervical junction and odontoid process under the concept of a minimally invasive surgical strategy, a cadaver study was performed.

METHODS

Sixteen artery-injected adult head specimens were used. Endonasal endoscopic approach was made through one- or two-nostril routes following the Jho's endonasal paraseptal technique. Rod-lens endoscopes, which were 2.7 or 4 mm in diameter, 18 cm in length with 0-, 30-, and 70-degree lenses, were used.

RESULTS

Surgical landmarks leading to the craniocervical junction were the inferior margin of the middle turbinate, nasopharynx and Eustachian tube. The nasopharynx was readily identified following the inferior margin of the middle turbinate. The line drawn between the Eustachian tubes indicated the juncture between the clivus and atlas. With a midline mucosal incision, the ventral cranio-cervical junction was exposed. Odontoid resection was performed with removal of the anterior arch of the atlas. Clival resection can be performed as much rostral as required. Maneuverability of the surgical instruments was better with a two-nostril technique than with a one-nostril. Although the entire midline clivus was accessible rostrally, C-2 was the caudal limit through this endonasal route. A suturing device needed to be developed for mucosal or dural closure for live operations.

CONCLUSION

This cadaver study demonstrates that an endoscopic endonasal approach to the ventral cranio-cervical junction and odontoid process can be a valid alternative to the conventional transoral approach.

Os odontoideum

DIAGNOSIS

STANDARDS

There is insufficient evidence to support diagnostic standards.

GUIDELINES

There is insufficient evidence to support diagnostic guidelines.

OPTIONS

Plain x-rays of the cervical spine (anteroposterior, open-mouth odontoid, and lateral) and plain dynamic lateral x-rays performed in flexion and extension are recommended. Tomography (computed or plain) and/or magnetic resonance imaging of the craniocervical junction may be considered.

MANAGEMENT

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

Patients with os odontoideum, either with or without C1--C2 instability, who have neither symptoms nor neurological signs may be managed with clinical and radiographic surveillance. Patients with os odontoideum, particularly with neurological symptoms and/or signs, and C1--C2 instability may be managed with posterior C1--C2 internal fixation and fusion. Postoperative halo immobilization as an adjunct to posterior internal fixation and fusion is recommended unless successful C1--C2 transarticular screw fixation and fusion can be accomplished. Occipitocervical fusion with or without C1 laminectomy may be considered in patients with os odontoideum who have irreducible cervicomedullary compression and/or evidence of associated occipitoatlantal instability. Transoral decompression may be considered in patients with os odontoideum who have irreducible ventral cervicomedullary compression.

Isolated fractures of the axis in adults

FRACTURES OF THE ODONTOID:

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

Type II odontoid fractures in patients 50 years and older should be considered for surgical stabilization and fusion.

OPTIONS

Type I, Type II, and Type III fractures may be managed initially with external cervical immobilization. Type II and Type III odontoid fractures should be considered for surgical fixation in cases of dens displacement of 5 mm or more, comminution of the odontoid fracture (Type IIA), and/or inability to achieve or maintain fracture alignment with external immobilization. TRAUMATIC SPONDYLOLISTHESIS OF THE AXIS (HANGMAN'S FRACTURE):

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

Traumatic spondylolisthesis of the axis may be managed initially with external immobilization in most cases. Surgical stabilization should be considered in cases of severe angulation of C2 on C3 (Francis Grade II and IV, Effendi Type II), disruption of the C2--C3 disc space (Francis Grade V, Effendi Type III), or inability to establish or maintain alignment with external immobilization. FRACTURES OF THE AXIS BODY (MISCELLANEOUS FRACTURES):

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

External immobilization is recommended for treatment of isolated fractures of the axis body.

Management of combination fractures of the atlas and axis in adults

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

Treatment of atlas-axis combination fractures based primarily on the specific characteristics of the axis fracture is recommended. External immobilization of most C1--C2 combination fractures is recommended. C1--Type II odontoid combination fractures with an atlantodens interval of 5 mm or more and C1--hangman's combination fractures with C2--C3 angulation of 11 degrees or more should be considered for surgical stabilization and fusion. In some cases, the surgical technique must be modified as a result of loss of the integrity of the ring of the atlas.

[Problems in the selection of surgical approach for the treatment of non-traumatic deformities of the craniocervical junction]

Developmental abnormalities or inflammatory disorders provoke deformations and instability of the craniocervical junction. The most dangerous results of these lesions are: sudden brainstem compression or cervical myelopathy. The authors propose the guidelines for surgical management of non-traumatic deformities caused by: a) rheumatoid arthritis of the spine, b) congenital anatomic changes of the occipit and odontoid. Main goals of surgical treatment are decompression and stabilization. The choice of surgical approach and method depends on pathology. It is very important to estimate individual anatomic changes and mobility--possibility of reduction. The authors discuss surgical methods actually used for fusion and decompression of the occipitocervical junction.

C1-C2 pedicle screw fixation with rigid cantilever beam construct: case report and technical note

OBJECTIVE AND IMPORTANCE

Transarticular screw fixation of the C1-C2 complex provides immediate rigid fixation of the unstable spine. The technique is not feasible in a certain proportion of patients because of the position of the vertebral artery or the patient's body habitus.

CLINICAL PRESENTATION

The authors describe a rigid screw technique for the surgical treatment of a woman who was excluded as a candidate for C1-C2 transarticular screw fixation.

TECHNIQUE

C1-C2 pedicle screw fixation was achieved using a fixed moment arm cantilever beam system. This system provided immediate rigid fixation of the C1-C2 complex in a patient who was not a candidate for transarticular screw fixation.

CONCLUSION

This technique is technically more forgiving than posterior transarticular screw fixation and may be applied to a broader spectrum of patients.