Review Question - QID 2893

Rupture of the central slip of the extensor tendon and subsequent subluxation of the lateral bands leads to a boutonnière deformity, which is characterized by PIP flexion and DIP extension. Central slip injuries can be caused by a laceration or traumatic avulsion. In the listed reference, Imatami et al treated a series of central slip injuries associated with attachment fractures successfully with ORIF. As stated by Tuttle et al, rupture of the terminal extensor tendon leads to a mallet finger. Sagittal band injury can lead to subluxation of the extensor tendon at the level of the MCP joint. Chronic volar plate injuries can lead to swan neck deformities. Avulsion of the FDP insertion leads to a jersey finger. Illustrations A and B are a clinical photograph and anatomic diagram of a boutonneire deformity.