Figure 1. Anteroposterior radiographic view of middle finger.
Figure 2. Lateral view of the same finger.
A 64-year-old woman presents with right hand pain after a fall taken 2 days earlier. The patient notes that the distal interphalangeal (DIP) joint of the right ring finger took the brunt of the fall. She reports pain and swelling at the DIP joint but no deformity is noted and she is able to fully extend the joint. Radiographs of the right ring finger are taken (Figures 1 and 2).
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Diagnosis of distal phalanx fracture is confirmed by history, physical examination, and radiography. The radiographs in this case show a displaced intra-articular dorsal base fracture of the distal phalanx. Distal phalanx fractures are the most common type of phalanx fractures.1 In the case of a base fracture, the mechanism can be shearing caused by axial load or avulsion due to tensile force.1
The vast majority of phalangeal fractures can be treated nonoperatively, even when there is some displacement. Dorsal base fractures in which the joint is congruent and the fracture pattern is stable can be treated with distal interphalangeal joint (DIP) immobilization. If the distal phalanx is subluxated from the middle phalanx and the fracture involves greater than 30% to 40% of the articular surface, open or closed reduction with percutaneous fixation is generally required. The terminal extensor tendon attaches to the dorsal base of the distal phalanx and acts to extend the DIP joint. Fractures of the dorsal base can cause an extension lag if there is disruption in the terminal extensor mechanism.1,2
The patient in this case has full extension at the DIP joint with an intact terminal extensor mechanism. The patient was treated with an aluminum and foam finger splint to the DIP joint to keep the joint congruent and in full extension.
1. Ahn L, Blomberg J. Phalanx fractures. OrthoBullets. Updated September 10, 2021. Accessed June 8, 2022. https://www.orthobullets.com/hand/6114/phalanx-fractureshttps://www.orthobullets.com/hand/6114/phalanx-fractures
2. Henry M. Fractures and dislocations of the hand. In: Bucholz RE, Heckman JD, Court-Brown C, ed. Rockwood and Green’s Fractures in Adults, 6th ed. Lippincott Williams & Wilkins; 2006:782-785.