Examination. Physical examination may reveal the presence of swelling/tenderness in the posterolateral aspect of the knee. Palpation of the fabella may suggest the presence of a firm nodule in the left posterolateral popliteal fossa, medial to the tendon of the biceps femoris, and approximately 1 cm in diameter.

How do I know if I have a fabella bone?

Medical professionals search for the fabella bone by palpating at the back of the knee and checking for swelling or tenderness in the surrounding area. If they believe the fabella is indeed the reason, an ultrasound or magnetic resonance imaging (MRI) is used to confirm their diagnosis.

Do all people have a fabella?

Not all people have fabellae, however, and there is likely a genetic component controlling the ability to form one – but for those who can form a fabella, this increased mechanical forces might drive their formation.