145 - Cervical and Cervicothoracic Deformity Correction: Posterior-Based Osteotomies

Abstract

Adult cervical deformity (ACD) can have a substantial impact on patient health, with moderate to severe deformity often causing significant disability and decline in functional status. The cervical spine has a much higher degree of mobility and flexibility relative to the thoracic and lumbar spine, contributing to the technical challenges of cervical deformity correction. Patients with ACD comprise a heterogeneous population, and as a result the surgical correction strategy should consider a variety of patient- and surgeon-independent factors. Important preoperative considerations include radiographic cervical alignment measurements, such as cervical sagittal vertical axis, cervical lordosis, and T1 slope, as well as the rigidity of the deformity. These specific parameters can be evaluated through physical examination, standing scoliosis x-rays, and dynamic flexion-extension films. Additionally, magnetic resonance imaging and computed tomography imaging are helpful for further evaluating the abnormal anatomy, bony fusion status, and presence of nerve root and spinal cord compression. When considering surgical intervention, soft tissue releases and osteotomies play a crucial role in cervical deformity correction, and can readily be classified using the Ames Cervical Osteotomy Grade. Most rigid cervical deformities can be addressed through a posterior approach, supplemented by anterior releases. Posterior-based osteotomies vary from low-grade osteotomies such as Smith-Petersen osteotomies to high-grade open and closed wedge pedicle subtraction osteotomies. This chapter focuses on the technical approaches to posterior-based osteotomies, their role in cervical deformity correction, and associated complications.