Epidemiological Investigation Of The Fabella And The Association Between The Fabella Degeneration And Osteoarthritis Grade In The Same Knee Joint

Objective: The purpose of this study is to examine radiographs prevalence and degeneration grade of fabella in Chinese subjects,and analyze the correlation between fabella degeneration and knee osteoarthritis grades.Materials and Methods: Bilateral or unilateral antero-posterior and lateral knee radiographs of 1150 patients(462 male subjects with 517 knees and 688 female subjects with 842 knees)were randomly selected from the clinical and inpatient database and retrospectively evaluated.Each knee plain films were examined knee osteoarthritis by Kellgren-Lawrence scoring system.The degeneration of fabella was scored by our evaluation system in each lateral knee radiographs.Results: The overall prevalence of the fabella was 48.57% in 1359 knees.There was no significantly difference between the prevalence of fabella in left and right knees,with 48.78% in left side and 48.36% in right side,respectively(?2=0.025,P=0.87437).There was no significantly difference between the prevalence of fabella in male and female,with 45.26% in male and 50.59% in female,respectively(?2=3.647,P=0.05617).The prevalence of fabella was increased among different age groups,with 8.18% in ?20 years age group,36.40% in 21-35 years age group,47.87% in the 36-50 years age group,58.17% in the 51-65 years age group and 79.28% in the ?66 years age group(?2=213.868,P=0).The degeneration of fabella was significantly different among different age groups(?2=208.954,p=0),the degenerated fabella was 0 in 13 subjects in ?20 years age group,18 in 91 subjects in 21-35 years age group,86 in 202 subjects in 36-50 years age group,113 in 178 subjects in the 51-65 years age group,160 in 186 subjects in the ?66 years age group.Age is significantly correlated with the degenerate of fabella(r=0.5288,P<0.001).The degeneration of fabella was correlated with the knee osteoarthritis grades(r=0.6892,p<0.001).Conclusions: Prevalence of fabella in Chinese was 48.57% with a female privilege and no lateral difference.The prevalence of fabella was increased with age increasing.The degeneration of fabella was correlated with ages and also the knee osteoarthritis grades.