Causes: How does a scaphoid fracture develop?
A scaphoid fracture most commonly results from a fall on an outstretched hand. When a scaphoid fracture is recognised on the first X-ray, treatment begins immediately. Since patients often assume that the injury is just a sprain it is often the case that they wait for it to heal on its own. In some instances, the wrist gets better however, in many cases the bone fails to heal. This can result in the scaphoid fracture developing into what surgeons call a non-union.
A non-union can occur in two ways i.e. a simple non-union, the two pieces of bone fail to heal together or the second type which is much more serious when the lower half of the fractured bone loses its blood supply and dies e.g. avascular necrosis. Only one small artery enters the bone, at the end that is closest to the thumb therefore, if the fracture tears the artery, the blood supply is lost. If a scaphoid fracture is left untreated, the bone is at risk of avascular necrosis.