1. Late spontaneous rupture of the extensor pollicis longus tendon following Colles's fracture is a rare complication, and one that is not often recognized. This Paper adds five cases to those previously reported in the literature.
2. The rupture is, in all probability, due to aseptic necrosis of the tendon. following injury to its blood supply.
3. The history and physical signs are very characteristic.
4. Return of function without operation cannot be expected. With operation, a good to excellent return of function may be expected.
5. Stress has been laid upon the dual function of the oblique pull of the extensor pollicis iongus tendon. and a method of repair has been suggested to accomplish this functional restoration.