busch fracture busch fracture in medicine a busch fracture is a type of fracture of the base of the distal phalanx of the fingers, produced by the removal of the bone insertion (avulsion) of the extensor tendon. without the appropriate treatment, the finger becomes a hammer finger. it would correspond to the group b of the albertoni classification. it is very common in motorcycle riders and soccer joggers, caused by hyperflexion when the tendon is exercising its maximum tension (the closed hand tightening the clutch lever or the brake lever). busch fracturefracture of the dorsal base of the distal falange by extensor tendon avulsion (busch fracture)specialtyorthopedic the busch fracture is named after friedrich busch (1844–1916), who described this type of fracture in the 1860s. busch's work was drawn on by albert hoffa in 1904, resulting in it sometimes being called a "busch-hoffa fracture". the mechanism of this injury can be described as an avulsion of the tendon fixed to the distal phalanx. avulsion of the part of the distal phalanx to which the tendon is attached, a finger fracture appearance: the last joint cannot be straightened. see mallet finger