Prevalence and characteristics of fabella in the Indian population – A radiograph-based prospective cross-sectional study

Objectives Fabella is a sesamoid bone in the tendon of lateral head of gastrocnemius, whose prevalence data are based on Asian and Western population studies with no prevalence data reported in Indian population. The present study aimed to examine plain knee radiographs in the Indian population, document prevalence and characteristics of fabella, and analyze its variations with age and gender. The presence of fabella with posterolateral knee pain was also correlated. Material and Methods This was a prospective cross-sectional study with all consecutive patients undergoing bilateral knee radiographs included in the study. Prevalence and characteristics of fabella were documented; significance of its presence with respect to age, gender; and laterality was calculated; and relationship with the presence of posterolateral knee pain was analyzed. Results 968 consecutive patients were enrolled with mean age of the subjects being 50 ± 16 years. The prevalence of fabella was maximum in the age group 51–60 years (41%). Overall prevalence of fabella was 27.05%. Posterolateral knee pain was present in 16.9% subjects, out of which fabella was present in 35.7%. The size of the fabella, however, was significantly larger in patients with posterolateral knee pain. Conclusion The prevalence of fabella in our study was less than what is reported for the Asian population. The presence of fabella did not have a significant relationship with posterolateral knee pain; however, its size in such patients was significantly larger, highlighting its role in posterolateral corner pathologies.