Rupture of the extensor pollicis longus tendon occurs occasionally following a fracture of the distal end of the radius. Rupture is probably due to damage to the tendon at time of fracture by the sharp edges of the fracture fragments with further attrition of tendon strength by aseptic necrosis of a section of the tendon.
The loss of tendon substance due to degeneration may be sufficiently great to necessitate tendon transfer. The extensor indicis proprius tendon can be used for transfer without loss of strength in the index finger, and it has adequate power to produce apparently normal extension of the thumb. Satisfactory transfer can be obtained by the use of pullout wise sutures according to the technique described by Bunnell.