Cory Calendine MD on Instagram: "Normal or Abnormal Knee Xray? . Some knee findings that can appear “abnormal” are actually common anatomical variants that rarely cause problems: Fabella: a small sesamoid bone found in approximately 30-40% of people, located within the lateral head of the gastrocnemius muscle behind the knee. On X-rays, this bean-shaped bone can be mistaken for a fracture fragment or loose body. Despite its intimidating appearance to the untrained eye, the fabella is a normal an