New Simple 3-Dimensional Computed Tomogram Classification Leading to Successful Conservative Treatment in 51 Atlanto-Axial Rotatory Fixation Children.

OBJECTIVE: to present a new and easy classification of atlanto-axial rotatory fixation (AARF) and to investigate the efficiency of conservative treatment of AARF. BACKGROUND: Although there is a precise definition and diagnostic classification of AARF, there is still significant difficulty in measuring the atlas and axis angles because all of the atlas or axis cannot be seen in a certain 2-dimensional computed tomogram image. In addition, some recent case reports showed that long-term conservative treatment can reduce pediatric AARFs, even that are severe or chronic. METHODS: Fifty-one children with AARF were analyzed retrospectively with new 3-dimensional computed tomogram (3DCT)-based AARF classification; the mean age was 72.7 ± 35.2 months (19-139 months). In the new AARF classification, type 1 was defined as that when the C1C2 angle is not 0° on midline and type 2 as that when the C1C2 angle is 0° on the midline. RESULTS: All 7 children with AARF type 1 were treated successfully only with Halter tractions. Twenty among 44 children with type 2 did not show any difference in improvement compared with not-treated 24 children with type 2. CONCLUSION: The first new AARF classification based on 3DCT appears to be easy to use and even the most severe children with AARF may be managed only with conservative treatment such as long-term Halter traction.