- Fabella
- Sesamoid bone of lateral gastrocnemius
- Normal variant in 10-20% of patients
- Posterior to lateral femoral condyle
- More common in early teen years
- Friction of fabella on posterolateral femoral condyle
- Slow, insidious pain onset
- Sharp, intermittent pain at posterolateral knee
- Localized tenderness over fabella
- Best examined with fully extended knee