Scoliosis in adult Type 1 Chiari malformation with syringomyelia patients: from pathogenesis to treatment.

The pathogenesis of type I Chiari malformation (CIM) is complex and remains unclear. The theory of posterior cranial fossa incompatibility has gained widespread acceptance in recent years. In the patients with CIM combined with syringomyelia, scoliosis is a common occurrence, with severe cases often leading to complications that necessitate surgical intervention. Scoliosis of various etiologies manifests as a three-dimensional structural spinal deformity. The etiology of scoliosis secondary to Chiari malformation is well-defined, and its imaging characteristics resemble those of idiopathic scoliosis. Vertebral rotation plays a critical role in the onset and progression of the deformity. However, spinal orthopaedic surgery in these patients is more challenging and hazardous due to the Chiari malformation and associated spinal cord abnormalities. Accurate preoperative assessment of scoliosis, Chiari malformation, and syringomyelia (SM), along with strategic planning of surgical approaches and fusion segment selection, is essential for improving patient outcomes and prognosis. In adults, CIM presents with more severe clinical manifestations compared to children, mainly including brainstem and cranial nerve compression, spinal-related syndromes, cerebellar injury syndromes, and hydrocephalus. Consequently, scoliosis deformities are often overlooked. Currently, there are limited reports on the efficacy of spinal correction surgery in adult patients with scoliosis associated with adult Type 1 Chiari malformation with syringomyelia (CIM-SM). Additionally, it remains uncertain whether and when syringomyelia should be addressed in these patients. This study aims to review previous research and explore whether intervention for Chiari malformation and syringomyelia should precede spinal orthopaedic surgery, as well as to evaluate the efficacy of spinal correction procedures.