Tag: Facet joint

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Posterior Reduction of Fixed Atlantoaxial Dislocation and Basilar Invagination by Atlantoaxial Facet Joint Release and Fixation

Posterior Reduction of Fixed Atlantoaxial Dislocation and Basilar Invagination by Atlantoaxial Facet Joint Release and Fixation- A Modified Technique With 174 Cases

Neurosurgery 78:391–400, 2016

Treatment of fixed atlantoaxial dislocation (AAD) with basilar invagination (BI) is challenging.

OBJECTIVE: To introduce a modified technique to reduce fixed AAD and BI through a posterior approach.

METHODS: From 2007 to 2013, 174 patients with fixed AAD and BI underwent surgical reduction by posterior atlantoaxial facet joint release and fixation technique.

RESULTS: There was 1 death in the series, and 3 patients were lost to follow-up. The follow-up period ranged from 12 to 52 months (mean: 35.2 months) for the remaining 170 patients. Neurological improvement was observed in 168 of 170 patients (98.8%), and was stable in 1 (0.06%) and exacerbated in 1 (0.06%), with the Japanese Orthopedic Association scores increasing from 11.4 preoperatively to 15.8 postoperatively (P , .01). Radiologically, complete or .90% reduction was attained in 107 patients (62.9%), 60% to 90% reduction was attained in 51 patients (30%), and ,50% reduction was attained in 12 patients (7.1%), who underwent additional transoral decompression. Complete decompression was demonstrated in all 170 patients. Solid bony fusion was demonstrated in 167 patients at follow-up (98.2%).

CONCLUSION: This series showed the safety and efficacy of the posterior C1-2 facet joint release and reduction technique for the treatment of AAD and BI. Most fixed AAD and BI cases are reducible via this method. In most cases, this method avoids transoral odontoidectomy and cervical traction. Compared with the occiput-C2 screw method, this short-segment C1-2 technique exerts less antireduction shearing force, guarantees longer bone purchase, and provides more immediate stabilization.

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Orientation of the facet joints in degenerative rotatory lumbar scoliosis

Orientation of the facet joints in degenerative rotatory lumbar scoliosis- an MR study on 52 patients

Acta Neurochir (2016) 158:473–479

Because of a degenerative component, degenerative rotatory scoliosis seems different from congenital and idiopathic subtypes of the disease. This study aims to examine the orientation of facet joints, as a known cause of degeneration, in patients with degenerative rotatory scoliosis.

Methods Lumbar magnetic resonance (MR) images and plain radiographs of 52 symptomatic patients (mean age, 50.17 years) with degenerative rotatory lumbar scoliosis (mean curve, 19.22 degrees) and 50 healthy individuals were reviewed. Facet joint angles in rotated segments and the minimum neural foramen width at all lumbar levels were measured by three observers and the average was recorded.

Results The maximum vertebral rotation was most frequent at L4-L5 (75 %), and the majority was of type I (84.6 %) according to the Nash-Moe classification. At all lumbar spinal levels the mean facet joint angles were significantly higher on the side of rotation (L2-L3, 57.92 degrees; L3-L4, 45.00 degrees; L4-L5, 43.88 degrees) compared to those on the contralateral side (L2-L3, 20.42 degrees; L3-L4, 15.48 degrees; L4-L5, 13.12 degrees) and in controls (L2-L3, 30.21 degrees; L3- L4, 40.81 degrees; L4-L5, 45.20 degrees) (p<0.001 for all comparisons). The mean facet joint angle increased significantly from L4-L5 to L2-L3 in cases and reversely in controls. The mean minimum neural foramen width was 1.29 ± 0.85 mm on the side of rotation, 5.50 ± 1.09 mm on the contralateral side, and 6.78± 1.75 mm in controls (p<0.001).

Conclusions Substantial asymmetries and abnormal orientations in facet joints were documented in patients with degenerative rotatory lumbar scoliosis. Such asymmetries may adversely affect neural foramen width.

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Surgical consideration of cervical dumbbell tumors

Surgical consideration of cervical dumbbell tumors

Acta Neurochir (2013) 155:1907–1910

Nineteen patients with cervical dumbbell tumors treated surgically were analyzed retrospectively.

Methods Surgical strategies for dumbbell tumor were discussed from the perspective of safe, less-invasive surgery.

Results Patients included 6 men and 13 women, with a mean age at the time of surgery of 48.3 years (range, 25–70 years). Underlying pathologies included 16 schwannomas, 2 neurofibromas, and 1 double tumor (schwannoma and meningioma). According to Eden’s classification, one patient was classified as Type 1, 5 as Type 2, 8 as Type 3, and 5 as Type 4. In 13 cases, tumors were excised through the posterior approach alone, compared to five cases using the anterior approach. One case was excised using combined anterior and posterior approaches. Facetectomy was not performed in 18 cases. In one case, the facet joint on one side had already destroyed and needed instrumentation. Tumors were totally excised in all cases. Postoperatively, the patients did not display any further neurological deficit, with the exception of transient radiculopathy in two patients. Major surgical complications and cerebrospinal fluid leakage were not seen. Tumor recurrence and spinal segmental instability were not found during follow-up period (mean, 41.6 months).

Conclusions Dumbbell tumor surgery requires sufficient debulking of the epidural and paravertebral mass, using intraoperative nerve stimulation and Doppler ultrasonography to detect the vertebral artery. When using a posterior approach, recapping laminoplasty using an ultrasonic bone curette is very useful to remove tumor without sacrificing facet joints.

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