• Neurospine
• /
• v.15 no.4
• /
• pp.323-328
• /
• 2018

The author reviews the various types of cervical fusion that are associated with instability of the craniovertebral junction. Assimilation of the atlas, C2-3 fusion, the Klippel-Feil abnormality, and pancervical fusion are amongst the more common types of bone abnormalities. It is conceptualised that these types of cervical fusion are not related to any kind of embryological dysgenesis or fault, but instead emerge due to longstanding muscle spasms of the neck in response to atlantoaxial instability. Such bone fusions could be secondary protective responses to longstanding atlantoaxial instability.

• Journal of Korean Neurosurgical Society
• /
• v.52 no.2
• /
• pp.120-125
• /
• 2012

Objective : To investigate the feasibility of C1 lateral mass screw and C2 pedicle screw with polyaxial screw and rod system supplemented with miniplate for interlaminar fusion to treat various atlantoaxial instabilities. Methods : After posterior atlantoaxial fixation with lateral mass screw in the atlas and pedicle screw in the axis, we used 2 miniplates to fixate interlaminar iliac bone graft instead of sublaminar wiring. We performed this procedure in thirteen patients who had atlantoaxial instabilities and retrospectively evaluated the bone fusion rate and complications. Results : By using this method, we have achieved excellent bone fusion comparing with the result of other methods without any complications related to this procedure. Conclusion : C1 lateral mass screw and C2 pedicle screw with polyaxial screw and rod system supplemented with miniplate for interlaminar fusion may be an efficient alternative method to treat various atlantoaxial instabilities.

• Journal of Korean Neurosurgical Society
• /
• v.52 no.1
• /
• pp.21-26
• /
• 2012

Objective : To evaluate a new posterior atlantoaxial fixation technique using a nitinol shape memory loop as a simple method that avoids the risk of vertebral artery or nerve injury. Methods : We retrospectively evaluated 14 patients with atlantoaxial instability who had undergone posterior C1-2 fusion using a nitinol shape memory loop. The success of fusion was determined clinically and radiologically. We reviewed patients' neurologic outcomes, neck disability index (NDI), solid bone fusion on cervical spine films, changes in posterior atlantodental interval (PADI), and surgical complications. Results : Solid bone fusion was documented radiologically in all cases, and PADI increased after surgery (p<0.05). All patients remained neurologically intact and showed improvement in NDI score (p<0.05). There were no surgical complications such as neural tissue or vertebral artery injury or instrument failure in the follow-up period. Conclusion : Posterior C1-2 fixation with a nitinol shape memory loop is a simple, less technically demanding method compared to the conventional technique and may avoid the instrument-related complications of posterior C1-2 screw and rod fixation. We introduce this technique as one of the treatment options for atlantoaxial instability.

• Journal of Korean Neurosurgical Society
• /
• v.55 no.5
• /
• pp.255-260
• /
• 2014

Objective : The purpose of this study was to compare the radiological and neurological outcomes between two atlantoaxial fusion method for atlantoaxial stabilization; C1 lateral mass-C2 pedicle screws (screw-rod constructs, SRC) versus C1-2 transarticular screws (TAS). Methods : Forty-one patients in whom atlantoaxial instability was treated with atlantoaxial fixation by SRC group (27 patients, from March 2005 to May 2011) or TAS group (14 patients, from May 2000 to December 2005) were retrospectively reviewed. Numeric rating scale (NRS) for pain assessment, Oswestry disability index (ODI), and Frankel grade were also checked for neurological outcome. In radiologic outcome assessment, proper screw position and fusion rate were checked. Perioperative parameters such as blood loss during operation, operation time, and radiation exposure time were also reviewed. Results : The improvement of NRS and ODI were not different between both groups significantly. Good to excellent response in Frankel grade is shown similarly in both groups. Proper screw position and fusion rate were also observed similarly between two groups. Total bleeding amount during operation is lesser in SRC group than TAS group, but not significantly (p=0.06). Operation time and X-ray exposure time were shorter in SRC group than in TAS group (all p<0.001). Conclusion : Both TAS and SRC could be selected as safe and effective treatment options for C1-2 instability. But the perioperative result, which is technical demanding and X-ray exposure might be expected better in SRC group compared to TAS group.

• Journal of Korean Neurosurgical Society
• /
• v.41 no.4
• /
• pp.248-251
• /
• 2007

Atlantoaxial rotatory dislocation [AARD] is an uncommon disorder of childhood in which clinical diagnosis is generally difficult and often made late. It is very rare in adults because of the unique biomechanical features of the atlantoaxial articulation. We report a case of post-traumatic AARD in an adult. Reduction was difficult to obtain by skull traction and gentle manipulation. Therefore, the patient was treated surgically by an open reduction, transpedicular screw fixation, and posterior C1-2 wiring with graft. The normal atlantoaxial relation was restored with disappearance of torticollis. Postoperatively, the patient remains neurologically intact and has radiographic documentation of fusion. Atlantoaxial transpedicular screw fixation can be one of the treatment options for the AARD.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.4
• /
• pp.580-585
• /
• 2000

The atlantoaxial rotatory fixation is a uncommon disease of deformity, occuring much more frequently in children than in adults. Despite of its benign clinical course, delayed recognition or improper management may cause persistent deformity or recurrence. We report three cases of typical atlantoaxial rotatory fixation. Successful reduction was achieved with posterior atlantoaxial fusion in one case and nonoperative treatment in others. We emphasize that it is necessary to perform dynamic CT scan to obtain correct diagnosis and to plan proper treatment for this disease entity.

• Journal of Korean Neurosurgical Society
• /
• v.42 no.5
• /
• pp.406-409
• /
• 2007

Craniovertebral junction (CVJ) tuberculosis is a rare disease, potentially causing severe instability and neurological deficits. The authors present a case of CVJ tuberculosis with atlantoaxial dislocation and retropharyngeal abscess in a 28-year-old man with neck pain and quadriparesis. Radiological evaluations showed a widespread extradural lesion around the clivus, C1, and C2. Two stage operations with transoral decompression and posterior occipitocervical fusion were performed. The pathological findings confirmed the diagnosis of tuberculosis. Treatment options in CVJ tuberculosis are controversial without well-defined guidelines. But radical operation (anterior decompression and posterior fusion and fixation) is necessary in patient with neurological deficit due to cord compression, extensive bone destruction, and instability or dislocation. The diagnosis and treatment options are discussed.

• Journal of Korean Neurosurgical Society
• /
• v.42 no.3
• /
• pp.179-183
• /
• 2007

Objective : Posterior arthrodesis in atlantoaxial instability has been performed using various posterior C1-2 wiring techniques. Recently, transarticular screw fixation (TASF) technique was introduced to achieve significant immediate stability of the C1-2 joint complex. The purpose of this study is to assess the clinical outcomes associated with posterior C1-2 TASF for the patient of atlantoaxial instability. Methods : We retrospectively reviewed data obtained from 17 patients who underwent C1-2 TASF and supplemented Posterior wiring technique (PWT) with graft between 1994 and 2005. There were 8 men and 9 women with a mean age of 43.5 years (range, 12-65 years). An average follow-up was 26 months (range, 15-108 months). Results : Successful fusions were achieved in 16 of 17 (94%). The pain was improved markedly (3 patients) or resolved completely (14 patients). There was no case of neurological deterioration, hypoglossal nerve injury, or vertebral artery injury. Progression of spinal deformity, screw pullout or breakage, and neurological or vascular complications did not occur. Conclusion : The C1-2 TASF with supplemental wiring provided a high fusion rate. Our result demonstrates that C1-2 TASF supplemented by PWT is a safe and effective procedure for atlantoaxial instability. Preoperative evaluation and planning is mandatory for optimal safety.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.1
• /
• pp.95-100
• /
• 2000

Objective : Posterior transarticular screw fixation is known to be one of the best surgical method for the atlantoaxial instability. We assessed the complication and operative risk in 15 patients. Patients and Methods : Between January 1997 and April 1998, 15 patients suffering from this condition were admitted to our institution. Atlantoaxial instability was caused by C1 or C2 fractures in 11, rheumatoid arthritis in 2, and os odontoideum in 2. This technique was used in the treatment of 13 patients and 2 patients was used in sublaminar wire fixation only. Bilateral C1-C2 screws were placed in 11 patients ; 2 patients had only one screw placed becauce of an anomalous vertebral artery and axial destruction. Follow-up period ranged from 5 to 20 months. Results : Most screws were positioned satisfactorily. One screw was malpositioned. No patients had neurological complications. Conclusion : Rigidly fixating C1-C2 instability with transarticular screws showed a significantly higher fusion rate than that achieved using wired grafts alone. The risk of screw malpositioning and catastrophic vascular or neural injury is small and can be minimized by assessing the position of the transverse foramen on preoperative computed tomographic scans and by correctly using intraoperative fluoroscopy and surgeon's precaution.

• Journal of Korean Neurosurgical Society
• /
• v.57 no.6
• /
• pp.460-464
• /
• 2015

Objective : Bilateral C1 lateral mass and C2 pedicle screw fixation (C1LM-C2P) is an ideal technique for correcting atlantoaxial instability (AAI). However, the inevitable situation of vertebral artery injury or unfavorable bone structure may necessitate the use of unilateral C1LM-C2P. This study compares the fusion rates of the C1 lateral mass and C2 pedicle screw in the unilateral and bilateral methods. Methods : Over five years, C1LM-C2P was performed in 25 patients with AAI in our institute. Preoperative studies including cervical X-ray, three-dimensional computed tomography (CT), CT angiogram, and magnetic resonance imaging were performed. To evaluate bony fusion, measurements of the atlanto-dental interval (ADI) and CT scans were performed in the preoperative period, immediate postoperative period, and postoperatively at 1, 3, 6, and 12 months. Results : Unilateral C1LM-C2P was performed in 11 patients (44%). The need to perform unilateral C1LM-C2P was due to anomalous course of the vertebral artery in eight patients (73%) and severe degenerative arthritis in three patients (27%). The mean ADI in the bilateral group was 2.09 mm in the immediate postoperative period and 1.75 mm in 12-months postoperatively. The mean ADI in the unilateral group was 1.82 mm in the immediate postoperative period and 1.91 mm in 12-months postoperatively. Comparison of ADI measurements showed no significant differences in either group (p=0.893), and the fusion rate was 100% in both groups. Conclusion : Although bilateral C1LM-C2P is effective for AAI from a biomechanical perspective, unilateral screw fixation is a useful alternative in patients with anatomical variations.