E5415. Caution This is a Rigid Spine! What Radiologists Need to Know
  1. Maryam Golshan Momeni; University of California, Irvine
  2. Peter Pham; University of California, Irvine
  3. Arash Anavim; University of California, Irvine
  4. Lawrence Wang; University of California, Irvine
  5. Joseph Burns; University of California, Irvine
The rigid spine (as differentiated from rigid spine syndrome, a congenital muscular dystrophy disorder), is defined as a disease or condition where there is bridging ossification or other fusion of spinal segments. Possible etiologies for this segmental bridging or fusion include diffuse idiopathic skeletal hyperostosis (DISH), ankylosing spondylitis (AS), and degenerative spondylosis, as well as surgical fusion of the spine. Due to the altered biomechanics, the stability of the rigid spine is inherently compromised, rendering the patient susceptible to fractures even in the case of a minor trauma. The most common mechanism of injury in this group is hyperextension injury. When patients with a known or suspected rigid spine exhibit new back pain or suspected spinal trauma, a CT spine scan is the initial diagnostic step. Additionally, it is imperative to maintain a low threshold for obtaining a noncontrast-enhanced spine MRI in these cases, as MRI can unveil occult fractures in these sometime osteopenic patients, evaluate epidural hematomas, and assess for potential spinal cord injuries. Unfortunately, delayed fracture diagnosis frequently arises due to inadequate imaging, unfamiliarity with fracture patterns within rigid spines, and a lack of heightened suspicion. This delay can lead to significant morbidity and even mortality. The radiologist's pivotal role lies in identifying distinct imaging characteristics of various rigid spine types, detecting fractures on both CT and MRI scans, and fully describing the injury's extent.

Educational Goals / Teaching Points
By the end of this exhibit, the participant should be familiar with the specific imaging features of different types of rigid spine, the different and most common mechanisms of injury and injury patterns related to the altered biomechanics of rigid spine, the necessary exams to improve patient outcome, and recognizing factors causing delays in diagnosis and how to prevent them and therefore optimize patient care.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
A survey of literature on important imaging findings of rigid spine and the pattern of most common injuries was performed. CT and MRI of the spine derived from our institutional database are being assembled to create this presentation.

Familiarity with the rigid spine and the mechanisms and patterns of injury, will improve the accuracy of image interpretation, more comprehensively characterizing injury extent. Additionally, utilization of different imaging modalities to evaluate for the possibility of surgical intervention will be discussed. By recognizing the characteristic fracture patterns and relevant features in patients with rigid spine presenting with back pain or after trauma, radiologists can avoid a missed and/or delayed diagnosis of an injured rigid spine.