Radiological examination of the prevalence and localization of the fabella bone in our population

The fabella is a sesamoid bone located usually on the lateral head of the gastrocnemius muscle, articulating with the posterior surface of the lateral femoral condyle. The prevalence of the fabella sesamoid bone varies between 10-30% in the population and is generally found bilaterally. The aim of this study is to investigate the prevalence of the fabella bone in the Turkish population, its distribution based on gender and age groups, lateralization characteristics, and size. For this study, the radiographic images and patient records of 1000 individuals (2000 knee images) who applied to the Radiology Department of Gaziosmanpaşa University Health Practice and Research Center between November 2016 and May 2021 for knee joint radiography were retrospectively examined. The fabella was identified in 15.8% of the total individuals. When examined by gender, it was observed in 14.9% of females and 17.8% of males, with no significant difference between genders. The highest prevalence was observed in middle-aged individuals, and the incidence of fabella increased with advancing age. While 42% were identified bilaterally, 58% were identified unilaterally. The fabella was generally located unilaterally on the right and left sides. When examining its location in the knee joint, the majority were located on the lateral side. When looking at the dimensions of the fabella, it was observed that the superior-inferior (SI) diameter of the fabella on the left side was larger than that on the right side. An increase in the SI diameter of the left-sided fabella with age was determined (p<0.05). However, there was no vii statistically significant relationship between the anterior-posterior (AP) diameter of the right and left sides and age. Our study highlights the importance of considering the presence of the fabella bone in the approach to the knee joint. Keywords: Fabella; Sesamoid; Radiography; Knee Joint