The results of delayed open reduction and internal fixation in chronic bony mallet finger injuries

The aim of this study was to evaluate the functional results of delayed open reduction and Kirschner wire (K-wire) fixation procedures in patients with delayed presentation of bony mallet finger.

Between February 2009 and November 2019, a total of 19 patients (15 males, 4 females; median age: 24.8 years; range, 14 to 47 years) who were diagnosed with a delayed bony mallet finger and treated with dorsal block pin, direct pinning, or the umbrella handle technique were retrospectively analyzed. The Crawford criteria were used to evaluate the outcomes. The degrees of range of motion (ROM) were measured by a goniometer.

The median time from injury to surgery was 41 (range, 28 to 90) days. The median DIP joint extension limitation was 7.63 (range, 0 to 40) degrees and the median ROM of the DIP joint was 66.3 (range, 20 to 90) degrees. There was no statistically significant difference in the postoperative ROM, compared to the uninjured side (p>0.05). The Crawford score was excellent in 11, good in four, fair in three, and poor in one patient. Bone union was achieved in all patients.

Delayed open reduction and K-wire fixation of chronic bony mallet finger injuries yield successful functional outcomes with low complication rates. Extension lag can be eliminated in most patients by making the joint surface anatomical. The most optimal method should be selected depending on the size of the fracture fragment.