The rupture of the insertion of the flexor digitorum profundus tendon is very uncommon, apart cases due to polyarthritis. Most cases are soccer, football or rugby players; the ring finger is the most affected. The traumatic agent is the sudden extension while the finger is holding an object and the flexor digitorum profundus is strongly contracted: the tendon retracts and the stump can be found either at the distal pulley, at the bifurcation of the superficialis tendon, or in the palm of the hand. Because of retraction, the trophic balance of the tendon is compromised: and this is very important in cases of delayed diagnosis, such as happens in 75% of cases. As a result, the treatment can be difficult and sometimes arthrodesis of the distal interphalangeal joint is the only possible therapy.