A new custom-made plate preparation method for bony mallet finger treatment and a comparison with extension block technique

Objectives In this study, we aimed to describe a new hook plate technique (HPT) and to compare our results with the conventional extension block technique (EBT) with a Kirschner wire (K-wire) for bony mallet finger treatment. Patients and methods Between April 2015 and January 2018, a total of 19 patients including 10 who were treated with EBT (7 males, 3 females; mean age: 30.1±7.3 years; range, 17 to 48 years) and nine who were treated with HPT (6 males, 3 females; mean age: 31.7±11.3 years; range, 19 to 42 years) for bony mallet finger with distal interphalangeal (DIP) joint subluxation and/or fracture fragment larger than one-third of distal phalanx (Wehbe-Schneider type 1/b, 2/a, 2/b, 3/a) joint were retrospectively analyzed. The DIP range of motion (ROM), Warren and Crawford scores, time to return to work/daily activity, operation time, the number of fluoroscopy shots, cost and complications were compared. Results No significant difference was found in the DIP ROM (p=0.708) and the Warren/Norris and Crawford scores (p=0.217 and p=0.175, respectively) between the two groups. Operation time and material cost were higher with HPT (p=0.006, p=0.001). There was no significant difference in the number of fluoroscopy shots (p=0.344). Although DIP joint motion was started at two weeks in the HPT group and at eight weeks in the EBT group, no significant difference was observed in the time of return to work and normal daily life in both groups (p=0.859). Complications were observed in two patients in the EBT group and in three patients in the HPT group. No significant difference in total complications was observed between the two groups (p=0.666). Conclusion Bony mallet finger treatment with a custom-made hook plate prepared from 1.3-mm AO plates appeared to be clinically and radiologically similar to EBT. Additionally, HPT had the advantages of allowing early ROM to DIP joint and eliminating the need for a secondary surgery such as K-wire removal. On the other hand, hardware cost with HPT was higher than EBT.