Unstable mallet fractures: a comparison between three different techniques in a multicenter study.

Abstract

Management of mallet fractures is still a matter of discussion throughout the literature. For some authors, mallet fractures involving more than 1/3 of the articular surface and palmar subluxation of the distal phalanx require surgical treatment. In this study we retrospectively compared three different techniques for mallet fractures: Kirschner wire fixation with extension block pinning (EBP) of the distal interphalangeal joint, Kirschner wires used as joysticks (KWJ) and interfragmentary mini-screws for open reduction and internal fixation (ORIF).
Fifty-eight mallet fractures with palmar subluxation in 58 patients were treated with the aforementioned surgical techniques. Twenty mallet fractures in 20 patients 18 to 70 years old (average 42 years) were operated upon by EBP, 16 patients 22 to 56 years old (average 56 years) were operated upon using KWJ and 22 patients 22 to 54 years old (average 36 years) received ORIF. Follow-up time was 6 to 58 months (average 21 months). The following intraoperative parameters were considered: intraoperative time, number of Kirschner wires/screws and technical problems. Postoperative parameters included work absence and complications. The radiological evaluation was based on A-P and lateral views preoperatively and interviews at follow-up time. Bone union was defined by radiological evidence of bone trabeculae crossing the fracture site on at least one view. Clinical evaluation involved range of motion (ROM) test with a goniometer. Based on these measurements, a functional Crawford score was established.
All fractures healed. In the KWJ group, intraoperative time was shorter and total ROM was wider (72 degree vs 58 degree and 54 degree; in the ORIF group, return to work was faster (2.7 weeks vs 7.2 weeks and 6 weeks) but a little higher complication rate due to screw positioning has been found. Functional results as to total ROM, distal interphalangeal lag extension and Crawford classification were similar.
We demonstrate the advantages of the use of the three techniques and bone consolidation in all cases with no signs of osteoarthritis. Screw fixation is more technically demanding (longer intraoperative time and more complications) but allows earlier mobilization and faster returning to work. EBP and KWJ techniques are faster to perform with no complications but require a careful management of the pin tracts. There is no statistically significant difference as to functional results.