Controversies in the surgical management of congenital craniocervical junction disorders - A critical review

Introduction: Congenital disorders of the craniovertebral junction (CVJ) include a wide range of conditions, such as Chiari malformation (CM), basilar Invagination (BI), and atlantoaxial dislocation (AAD). The objective of this paper is to critically review the literature related to the management of congenital CVJ disorders focusing on: the significant developments in the past (from anterior open ventral decompression to modern CVJ realignment); the diagnosis of CVJ instability; the role of atlantoaxial fixation without posterior fossa decompression in patients with tonsillar herniation and no evidence of CVJ instability; use of C1-2 inter-articular spacers and use of C1-2 interarticular spacers with intra-operative manipulations to correct BI with AAD along with its deformity. Materials and Methods: We performed a review of articles showing up on PubMed database without time restriction. Articles were included according to the purpose of our review and selected by two authors (AFJ and PSC). Results: CVJ instability may be inferred when there is atlantoaxial abnormal motion seen on dynamic studies, facet joint subluxation or severe symptomatic CVJ kyphosis; routine fixation of patients with CM without clear CCJ instability, while based on an interesting hypothesis, still requires further studies; use of C1-2 inter-articular spacers for re-establishing CVJ alignment is probably the most effective surgery for posterior CVJ realignment and reduction of AAD and BI, potentially avoiding the need for an open or endoscopic anterior odontoidectomy (AO); current development of deformity correcting surgeries and the measurement of joint indices to plan surgery have provided new strategies for treatment. Conclusion: We present a critical review of important new concepts involved in the surgical treatment of CVJ congenital disease.