[Subcutaneous rupture of the long thumb extensor tendon. Etiology, clinical aspects and therapy].

Subcutaneous ruptures of the extensor pollicis longus tendon are mostly due to an earlier wrist trauma and rarely caused by a degenerative systemic disease. The tendon usually ruptures close to the distal edge of the retinaculum extensorum where it is vulnerable in various respects and in addition exposed to increased mechanical strain. Functional loss of the extensor pollicis longus greatly impairs the function of the entire hand and requires surgical therapy. Transfer of the extensor indicis tendon has proven successful in 95% and thus appears to be the most appropriate therapeutic procedure.