Full Length ArticleProgressive halo-vest traction preceding posterior occipitocervical instrumented fusion for irreducible atlantoaxial dislocation and basilar invagination

•Halo-traction was safe and effective in reduction of IAAD and BI.•Cervical spine was fixed at extension position while maintaining traction.•50% reduction of deformity could be achieved by preoperative Halo traction.

ObjectivesSurgical treatment of irreducible atlantoaxial dislocation (IAAD) with basilar invagination (BI) is associated with high rates of severe complications, including mortality. This retrospective study investigated the safety and efficacy of progressive halo-vest traction for IAAD with BI prior to posterior occipitocervical instrumented fusion.Patients and methodsBetween 2009 and 2013, 39 patients with IAAD with BI underwent preoperative reduction by progressive halo-vest traction for 20.82 ± 4.21 days. Instrumented fusion was then performed through a posterior approach. Clinical outcomes were based on pain scale and Japanese Orthopedic Association (JOA) scores. Radiographic analysis evaluated changes in atlantodental distance, McGregor's line violation, spinal canal width at the craniocervical junction, cervicomedullary angle, C2-C7 lordosis angle, and the occiput-C2 angle.ResultsFollow-ups ranged from 48 to 96 months. Both atlantodental distance and BI significantly improved in all patients. The rates of complete anatomical reduction were 85% for IAAD, and 95% for BI. Most of the patients reported satisfactory pain relief and improvement in daily activity; the mean JOA scores at baseline and last follow-up were 9.10 and 15.92, respectively. Although complications occurred in 10 patients (25.64%), all of which healed uneventfully. The bony fusion rate was 100%.ConclusionProgressive halo-vest traction before surgery is safe and effective for reduction of IAAD with BI. The technique we describe is a promising method for treatment of complex craniocervical junction deformity.