Posterior occipitoaxial fusion for atlantoaxial dislocation associated with occipitalized atlas

Abstract

Between 1989 and 1994, 50 patients suffering from congenital atlantoaxial dislocation with either an assimilated atlas or a thin or deficient posterior arch of the atlas were treated with occipitocervical fusion using the technique described by Jain and colleagues in 1993 with a few modifications. An artificial bridge created from the occipital bone along the margin of the foramen magnum was fused to the axis using sublaminar wiring and interposed strut and lateral onlay bone grafts. Ten patients (20%) also underwent atlantoaxial lateral joint fusion by intraarticular instillation of bone chips. In 22 patients (44%) with irreducible dislocation, posterior fusion was preceded by transoral odontoidectomy. In seven patients (14%) with ventral compression, who showed marked clinical improvement on traction despite radiological evidence of persisting atlantoaxial dislocation, occipitocervical fusion was performed without ventral decompression. Seven patients (14%) underwent a single-stage transoral odontoidectomy and posterior fusion. There was no perioperative mortality and the osseous fusion rate was 88%. Of the 43 patients available at follow-up examination (range 3-12 months), 31 patients (72.09%) improved, seven (16.28%) remained the same, and five (11.6%) deteriorated in comparison with their preoperative status. Hence, this technique achieves a stable occipitocervical arthrodesis without supplemental external orthoses and facilitates early postoperative mobilization.

Management of Pediatric Congenital Atlantoaxial Dislocation: A Report of 23 Cases from Northern India

“…Occipitalization of the atlas was the commonest, being present alone or in combination in 10 patients, which is much higher than the expected incidence (0.25–2.17%) in any given population [19]. This had a bearing on our management, and we had to resort to Jain’s technique [5, 6]of occipitocervical posterior fusion in such patients. Os odontoideum was an anomaly encountered in 8 of our patients, but its etiology remains blurred [20].…”

“…In our study, 23 children underwent comparatively simple procedures (Jain’s technique and modified Brooks’) for posterior stabilization. These methods were originally described for adults [5, 6, 7]and were successfully translated in children with various congenital osseous malformations in our series. The special attributes of these methods which permitted their use in children were the following: (1) a relatively small mass of bone is required for fixation, and (2) the devices (stainless steel wires 22 G) are not bulky and can be easily accommodated in the CV junction.…”

“…Thirteen children underwent posterior fusion by Jain’s technique [5, 6]. Ten children underwent fusion by a modification of Brooks’ technique [7].…”

“…Posterior stabilization was done by means of sublaminar wiring; we used either Jain’s technique of occipitocervical fusion [5, 6]or a modification of Brooks’ technique [7]in 13 and 10 patients, respectively. In Jain’s technique of occipitocervical fusion, an artificial arch (artificial C1 arch) was created in the occipital squama approximately 1 cm above the margin of the foramen magnum and used for fusion with C2 or the fused C2–3 vertebrae by means of sublaminar wires (stainless steel 22 G).…”

Posterior Instrumentation for Occipitocervical Fusion

“…Posterior surgical decompression remains invaluable for the treatment of these lesions in select cases, as well as the posteriorly situated lesions. Reduction surgery and internal fixation are chosen when positioning or traction alone are adequate for the realigning of the column, but irreducible deformities need additional decompressive surgery using an anterior/transoral or posterior approach depending on the site of compression [7,9,10]. …”