Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Apr;55(4):198-201.
doi: 10.11622/smedj.2014052.

Incidence and radiological characteristics of fabellae in an Asian population

Chee Ping Chew  1 , Kong Hwee Lee, Joyce Suang Bee Koh, Tet Sen Howe
Affiliations

Incidence and radiological characteristics of fabellae in an Asian population

Chee Ping Chew et al. Singapore Med J. 2014 Apr.

Abstract

Introduction: The fabella, a sesamoid bone sometimes found in the lateral head of the gastrocnemius muscle, often articulates directly with the lateral femoral condyle. This study aimed to determine the incidence of fabellae in an Asian population and to characterise the radiological features of the fabella.

Methods: Electronic radiographs and magnetic resonance imaging films of 80 consecutive patients who underwent knee arthroscopy between May 2005 and October 2009 were reviewed to determine the presence and characteristics of the fabella.

Results: The incidence of fabellae was 31.25% in our study cohort. The median length, thickness, width and distance of the fabella from the lateral femoral condyle were 7.06 mm, 4.89 mm, 6.12 mm and 33.19 mm, respectively. The fabella was consistently bony and located in the lateral head of the gastrocnemius, with 52% of the fabellae having an articulating facet. Fabellae in men were found to be larger than in women, although the difference was not statistically significant. The presence of an articulating groove was associated with increased size of the fabella, but not with the distance between the fabella and its insertion onto the lateral head of the gastrocnemius.

Conclusion: The incidence of fabellae in our population was lower than that in regional studies. They were consistently bony and not all had articulating grooves on the lateral femoral condyle. We found that the larger the fabella, the higher the chances of it having an articulating groove. By defining the radiological characteristics of the fabella, we provide objective parameters to help differentiate the fabella from other loose bodies or calcifications in the knee.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Sagittal MR image of the knee shows the measurement of the maximum length of the fabella (double-headed arrow).
Fig. 2
Fig. 2
Sagittal MR image of the knee shows the measurement of the maximum thickness of the fabella (double-headed arrow).
Fig. 3
Fig. 3
Axial MR image of the knee shows the measurement of the maximum width of the fabella (double-headed arrow).
Fig. 4
Fig. 4
MR image of the knee shows the measurement of the distance between the fabella and the insertion of the lateral head of the gastrocnemius onto the femur (double-headed arrow).
Fig. 5
Fig. 5
MR images of the knee show (a) concave and (b) flat contours of the articulating facet of the lateral femoral condyle of the femur.
See this image and copyright information in PMC

References

    1. Duncan W, Dahm DL. Clinical anatomy of the fabella. Clin Anat. 2003;16:448–9. - PubMed
    1. Crouch JE. Philadelphia: Lea & Febiger; 1969. Text-atlas of cat anatomy.
    1. Miller ME, Evans HE, Christensen GC. 2nd ed. Philadelphia: Saunders; 1979. Miller’s anatomy of the dog; pp. 205–15.
    1. Kaplan EB. The fabellofibular and short lateral ligaments of the knee joint. J Bone Joint Surg Am. 1961;43:169–79. - PubMed
    1. Sarin VK, Erickson GM, Giori NJ, Bergman AG, Carter DR. Coincident development of sesamoid bones and clues to their evolution. Anat Rec. 1999;257:174–80. - PubMed

LinkOut - more resources