Spinal fixation. Part 1. Principles, basic hardware, and fixation techniques for the cervical spine.

Spinal fixation devices provide stability and restore anatomic alignment in the treatment of fractures, degenerative disease, infection, and tumors and correct congenital deformities such as those seen in scoliosis. The devices provide immediate stability but are not strong enough to withstand prolonged stress and eventually fail, in most cases, if bone fusion does not occur. Bone graft material is often used to promote fusion and to replace bone after resection. Internal fixation is used to maintain position and alignment and to prevent motion as the spine fuses. Plates and rods are attached to the vertebral body or posterior elements with wire, screws, and hooks. Screws and wire can also be used alone as a means of fixation. Surgical techniques and instrumentation have advanced in recent years, and radiologists are exposed to a myriad of devices. They need to be able to identify the various plates, screws, wiring techniques, and grafts used most commonly and to understand their function in the cervical spine for fusions and treatment of fractures and degenerative disease.