RELIABILITY OF OSEBOLD, MALONEY, AND THE ALLEN AND FERGUSON METHODS FOR MEASUREMENT OF PELVIC OBLIQUITY IN PATIENTS WITH ADOLESCENT IDIOPATHIC SCOLIOSIS

ABSTRACT Objective: To evaluate the inter- and intraobserver reliability of the Osebold, Maloney, and the Allen and Ferguson methods for evaluating pelvic obliquity in patients diagnosed with adolescent idiopathic scoliosis (AIS). Methods: A reliability study of three methods of pelvic obliquity assessment was conducted in 148 randomly selected patients with AIS. The methods used to measure pelvic obliquity were those of Osebold, Maloney and Allen and Ferguson. The inter- and intraobserver Intraclass Correlation Coefficient (ICC) was calculated for each method as a reliability measure. Results: The mean measured by each method was 2.42° for Osebold, 2.5° for Maloney, and 8.14° for Allen and Ferguson. There were no significant differences in the interobserver evaluations in the first two techniques. However, the Allen and Ferguson scales showed significant differences. The following methods were respectively: 0.918 [95% CI = 0.807 - 0.965]; 0.825 [95% CI = 0.727 - 0.905] and 0.805 [95% CI = 0.645 - 0.899]. In the interpatient evaluation, the following were, respectively: 0.937 [95% CI = 0.887 - 0.967]; 0.911 [95% CI = 0.860 - 0.942] and 0.751 [95% CI = 0.114 - 0.906]. The intraobserver agreement analysis (ICC) was excellent for the Osebold and Maloney scales, while the Allen and Ferguson scales exhibited a lower level of agreement. Conclusions: The three methods showed good or excellent reliability in evaluating pelvic obliquity in AIS. The Osebold method, however, presented the best performance in the intraobserver and interobserver analyses. Level of Evidence III; Cross-Sectional Study.