Flexor digitorum profundus avulsions with associated distal phalanx fractures. A report of four cases and review of the literature.

A review of the current literature reveals that avulsions of the flexor digitorum profundus tendon, with a separate and concomitant intraarticular fracture of the distal phalanx, is an uncommon and easily misdiagnosed injury that has been infrequently described. This report encompasses a review of four patients with such an injury, and includes treatment recommendations for this complex injurious pattern. A classification system for flexor digitorum profundus avulsions is reviewed and it is proposed that the avulsion of the flexor digitorum profundus tendon with concomitant and separate intraarticular fracture of the distal phalanx, be added to the classification as a Type IV injury.