Is the Fielding Classification System Enough for Managing Atlantoaxial Rotatory Dislocation?

Objective: To assess the Fielding classification system for management of atlantoaxial rotatory dislocation (AARD). Summary of Background Data: AARD is a rare condition that occurs more commonly in children than in adults. The classification system proposed by Fielding in 1977 is most frequently used for AARD, and this classification system was devised in the days before the advent of computed tomography. Methods: We discuss the efficacy of the Fielding classification system in this rare but significant disorder. Conclusions: The Fielding classification system should be modified on the basis of radiologic results to prevent some cases from being classified mistakenly as the more serious type and treated through nonoperative intervention.