Fractured hand x-ray. Colored X-ray of a 24 year old who has fractured the third metacarpal bone. The metacarpals are the five long cylindrical bones that run from the base of each finger to the wrist. Metacarpal bones are covered by thick connective tissue and are formed from the knuckles. Fractured metacarpal bones are common, usually resulting from a blow to the knuckles or a fall.