Abstract
The classification of knee osteoarthritis allows assessment of disease severity and may be useful in guiding treatment decisions. One of the most widely used systems for this purpose is the Ahlbäck classification. This study aimed to compare the original description of the Ahlbäck classification with how it has been reported and cited by other authors in subsequent publications. We conducted a search in the PubMed, Embase, and Cochrane databases for articles containing exclusively the terms "knee", "osteoarthritis", "osteoarthrosis", and "Ahlbäck classification". After applying the inclusion and exclusion criteria, 64 articles remained. These articles were analyzed in two aspects: the description of the Ahlbäck classification (categorized as correct, partially correct, or incorrect) and the accuracy of the reference citation (correctly or incorrectly cited). Only 10 articles (15.6%) correctly described the Ahlbäck classification and cited the original source properly. In contrast, 37 publications (58.4%) contained errors both in the description of the classification and the citation. Conversely, 37 publications (58.4%) contained errors both in the description of the classification and in the bibliographic reference. The proportion of articles that accurately described and cited the Ahlbäck classification was markedly low, comprising only 15.6% of those included in this systematic review. Level of Evidence III; Systematic Review .