Distraction, Compression, and Extension Reduction of Basilar Invagination and Atlantoaxial Dislocation

Abstract

BACKGROUND: The management of basilar invagination (BI) and atlantoaxial dislocation (AAD) is a challenge. OBJECTIVE: To describe a new innovative method to reduce BI and AAD through a single-stage posterior approach. METHODS: Thirty-five patients had irreducible BI and AAD (May 2010 to April 2012). In all patients, reduction of AAD and BI was achieved by using an innovative method of distraction and spacer placement, followed by compression and extension. A C1 lateral mass/C2 translaminar screw was performed in cases where the C1 arch was not assimilated, and occipito-C2 translaminar screw fixation was performed in cases where the C1 arch was assimilated. RESULTS: Thirty-two of 35 (94%) patients improved clinically and 2 patients had stable symptoms (mean Nurick postoperative score = 1.4; preoperative score = 3.7). AAD reduced completely in 33/35 patients and >50% in 2. BI improved significantly in all patients. Solid bone fusion was demonstrated in 24 patients with at least 1-year follow-up (range, 12-39 months; mean, 19.75 + 7.09 months). The duration of surgery was 80 to 190 minutes, and blood loss was 90 to 500 mL (mean, 170 ± 35 mL). There was 1 death because of cardiac etiology and 1 morbidity (wound infection). CONCLUSION: Distractive compressive extension and reduction of BI and AAD seems to be an effective and safe method of treatment. It is different from the earlier described techniques, because it is the first procedure that uses a spacer not, only for distraction, but also as a pivot to perform extension to reduce the AAD.

Computed tomography, magnetic resonance imaging and a novel surgical approach of atlanto-axial instability with incongruence in dogs

“…The main characteristic of incongruence is represented by the disruption of this relationship, which was assessed in this study in CT multiplanar images of all affected patients. The combined diagnostic approach described herein, which included both CT and MRI, is consistent with the described approach recently described in veterinary research and used in human medicine for complete evaluation of the cranio-spinal junction [8,14,16,25].…”

Surgical management of adult reducible atlantoaxial dislocation, basilar invagination and chiari malformation with syringomyelia

“…Recently, several reports (4,8,24,28) have claimed that posterior fixation is an effective method to treat AAD and …”

“…According to these reports, occipitocervical fusion and C1 and C2 fusion are two main fixations. Chandra et al (4) reported that using an innovative method of distraction and spacer placement followed by compression and extension can reduce AAD and BI. Goel et al (15) used of the plate and screw method (C1/2 fusion) of fixation in the treatment of 160 patients with atlantoaxial instability and achieved good outcomes with low incidence of complications.…”

“…However, anterior transoral odontoid resection, combined with posterior decompression, instrumentation and craniocervical fusion in situ have a risk of predisposing the patient to cerebrospinal fluid leakage and neurological deficits (5,20). For these reasons, a posterior approach to fixation has gained popularity and been demonstrated to be effective over other fixation (1,4,16,17). More recently, it has been shown that distraction at the C1/C2 joints leads to a possibility of reduction of BI even in irreducible cases (10,12,22).…”

Technique for direct posterior reduction in irreducible atlantoaxial dislocation: Multi-planar realignment of C1–2

“…Often these dislocations are irreducible and may have additional non-correctable rotational and lateral components. The recent trend has shifted from traditional transoral decompression and posterior fusion to a direct posterior release of facets and reduction of dislocation [2][3][4][5][6][7][8]. Correction of all the components of dislocation and fixation in realigned position is desirable.…”