An extra thumb has been labeled many different ways: ‘radial polydactyly, thumb polydactyly, split thumb, and duplicated thumb’. My preferred name is radial polydactyly as it tells you exactly the issue. The term ‘duplicated thumb’ is not ideal as the thumbs are both smaller than normal but ‘split thumb’ is not perfect either because the thumbs are usually more than 50% of the size of the opposite thumb.
Radial polydactyly is typically both a functional problem and an appearance issue. Surgery is recommended. However, surgery is not simply removing the extra thumb- it is a reconstructive procedure that can range from a moderately complex procedure to a very complex procedure. There is no ideal time for surgery but typically surgeons choose to operate between 1 and 2 years of age. Sometimes the thumbs are merged to make the best, combined thumb and sometimes the bigger, more mobile thumb is reconstructed to make it stable and straight. Surgery can involve soft tissues only but often also involves bone surgery. A second procedure is required in some patients as they get older.
In this case, an older child had the smaller, outer thumb removed with a stabilization and reconstruction of the larger thumb.