Review Question - QID 4362

The radiograph depicts a bony mallet injury with volar subluxation of the distal phalanx after splinting of the DIP joint in extension, which is an indication for reduction and pinning.  

A mallet deformity is caused by disruption of the terminal extensor tendon distal to DIP joint. Occasionally, a bony avulsion of the distal phalanx is noted on radiographs. "Bony" mallet fingers will rarely require surgical fixation. It is important to attempt to splint a bony mallet injury and get a new radiograph prior to making the decision for operative treatment. Indications for surgical management of this condition include volar subluxation of the distal phalanx even after DIP splinting.

Stern et al. found a higher long-term complication rate with surgical treatment of mallet injuries. He also noted 15 degrees more DIP flexion at follow-up in the splinting group compared to the surgical group.

Pegoli et al. describe an extension block technique for treatment of this injury with good results. Their indications for surgery included the presence of a large bone fragment, and palmar subluxation or the loss of joint congruity of the distal interphalangeal joint.

Theivendran et al. review the surgical treatment of DIP joint fractures and state that 30% articular involvement is an indication for operative treatment.

Figure A shows a lateral radiograph with a large intra-articular bony avulsion fragment and volar subluxation of the distal phalanx.

Incorrect Answers:
Answer 2,3,4: This patient meets the indications for ORIF and nonoperative modalities would not be appropriate.
Answer 5: A DIP fusion in a young patient would not be appropriate.