The author's observations are based on many months of experience in the hospital of the Swiss Traumatic Surgical Insurance Association. Variations from the normal forms of the skeletal system are not unusual in the hands and feet. They occur as supernumerary elements or as fusions of normally independent skeletal segments. Other varieties occur in relation to form, size and type of individual bones, either by partial malformations or by variations in normal positions.
The interpretation of roentgenograms with accessory bone elements following trauma may be difficult. These elements may be mistaken for fractures or arthritic changes. Likewise, the reverse may be true. When judging traumatic surgical cases, a mistake may have serious financial and social consequences. For that reason, correct differential diagnosis is necessary. The complexity of the problem is well known. While these varieties were considered at one time to be "sports of nature," there may be a connection,