Spinal Alteration of Motion Segment Integrity Using the Sixth Edition

Abstract

Abstract Spinal impairment evaluation includes determination of the presence or absence of alteration of motion segment integrity (AOMSI). The diagnosis-related estimate (DRE) method is the principal methodology used to evaluate spinal AOMSI impairment in the fourth and fifth editions of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides). In the AMA Guides, Sixth Edition, impairment ratings are calculated using the diagnosis-based impairment (DBI) method that uses five impairment classes determined by diagnoses and specific criteria, adjusted by consideration of non-key factors and grade modifiers. This article includes a correction of numbers in the AMA Guides, Sixth Edition, Figure 17-6. The following factors must be considered to determine if AOMSI is present: 1) flexion/extension radiographs are performed when the individual is at maximum medical improvement and are technically adequate; 2) the proper methodology is used in obtaining measurements of translation and angular motion; 3) normal translation and angular-motion thresholds consistent with the literature are used in determining AOMSI. Imaging modalities such as videofluoroscopy, digital fluoroscopy, and upright/motion magnetic resonance imaging cannot be used to establish an AOMSI permanent impairment using the AMA Guides. A number of technical factors can affect the image quality associated with measurements of AOMSI, including film centering, artifacts, poor edge resolution, endplate normal variations and spurring, and use of analog rather than digital radiography.