The fabella has been rarely considered a possible cause of knee dysfunction. We report five cases of knee disorders caused by fabella. The first case was a 15-year-old female who complained of posterolateral pain and tenderness of the knee. Roentgenograms revealed the fabella with no obvious abnormalities. After failure of conservative treatment, the patient had gradual relief of symptoms following fabellectomy.
The second case was a 22 year old male with similar symptoms to the first case. These two were diagnosed as the fabellar syndrome.
The third case was a 60 year old male who complained of tenderness and extension pain in the fabellar region. On roentgenogram, a bipartated fabella was revealed.
Two other cases were in 77 and 78-year-old females who both suffered from tenderness and extension pain behind the knee. In both cases, roentgenograms showed large and degenerated fabella and severe lateral femorotibial osteoarthritis. They were diagnosed as fabello femoral osteoarthritis.
