BACKGROUND: One-stage anterior release and posterior reduction is one of the most effective methods for irreducible @entity3029 . However, the criteria of appropriate tissue release for successful posterior reduction is yet to be confirmed. Hence, an assistant technique using the transoral approach to verify satisfactory release is required. To evaluate the efficacy of the modified technique of transoral release for irreducible @entity3029 (IAAD) with @entity1 underwent one-stage anterior release and posterior reduction. METHODS: Between January 2009 and June 2014, 23 consecutive @entity1 diagnosed with IAAD free from bony union between the C1-C2 facet joints on reconstructive computed tomography scan underwent one-stage anterior release and posterior reduction after no response to 2 weeks of skull traction. During transoral release, an elevator was used as a lever repeatedly to confirm a 3-5  mm bilateral joint space between the lateral masses of the atlas and @entity2270 . The release was accomplished since a 3-5  mm joint space was achieved. After anterior release, posterior reduction and instrumented fusion were subsequently performed. RESULTS: All @entity1 were observed for an average of 18 (range 6-50) months. Nineteen of 23 @entity1 achieved complete reduction while four had an incomplete reduction. Significant differences in pre- and postoperative JOA scores and cervicomedullary angle (CMA) were found. Twenty-one @entity1 presenting with @entity602 had a JOA score of 12.9 at final follow-up, improved from 7.8 before surgery. The mean CMA improved to 143.5   postoperatively from 101.8   preoperatively. Bony fusion was confirmed in all cases under radiologic assessment during follow-up; there were no instrument failures. CONCLUSION: The modified technique of transoral release provides appropriate criteria for anterior release, to achieve good posterior reduction without excessive tissue release or intraspinal manipulation, proving its value as an assistant technique in one-stage anterior release and posterior reduction for IAAD.

Modified technique of transoral release in one-stage anterior release and posterior reduction for irreducible XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity2270 :: ('MESH:C566610', 'Disease') :: ['axis'] @entity602 :: ('MESH:D013118', 'Disease') :: ['myelopathy'] @entity3029 :: ('MESH:D004204', 'Disease') :: ['atlantoaxial dislocation']
@entity3029 :: (MESH:D004204,Disease) :: ['atlantoaxial dislocation']
