Surgical treatment of bony mallet fingers is frequently recommended, but the evidence is sparse. This randomized clinical trial aimed to compare nonoperative splinting versus extension-block pinning of bony mallet fingers with involvement of more than one-third of the joint surface but without primary joint subluxation. Thirty-two patients were randomized and 28 fulfilled the protocol. At 6 months follow-up, there were no significant differences in active extension lag in the distal interphalangeal joint (the primary outcome) or in patient-reported function and pain scores. Flexion and active range of motion in the distal interphalangeal joint and finger-to-palm distance were better in the splinting group, but three patients developed secondary subluxation. We conclude from this study, that splinting these injuries is safe and efficient in restoring joint motion, but splinting does not sufficiently prevent secondary subluxation of the joint. Radiographic follow-up during splinting appears to be necessary. Level of evidence: I.
Keywords: Randomized controlled trial; extension block Kirschner wire; mallet finger; mallet fracture; splint.