[Effectiveness comparison of open reduction and hook plate fixation versus closed indirect reduction and dorsal extension blocking Kirschner wire fixation for bony mallet finger].

Objective: To compare the effectiveness of open reduction and hook plate fixation versus closed indirect reduction and dorsal extension blocking Kirschner wire fixation for bony mallet fingers.

Methods: The clinical data of 68 patients with bony mallet finger who admitted between May 2019 and June 2022 were retrospectively analyzed. Among them, 33 cases were in the open group (treated with open reduction and hook plate fixation) and 35 cases were in the closed group (treated with closed indirect reduction and dorsal extension blocking Kirschner wire fixation). There was no significant difference between the two groups in terms of gender, age, the affected side, the affected finger, cause of injury, time from injury to operation, and Wehbé-Schneider classification ( P>0.05). The operation time, intraoperative fluoroscopy frequency, fracture healing time, time of returning to work, and postoperative complications were recorded and compared between the two groups. At 12 months after operation, visual analogue scale (VAS) score was used to assess the pain of the injured finger, active flexion range of motion and extension deficit of the distal interphalangeal joint (DIP) were measured by goniometer, and the effectiveness was assessed by Crawford criteria.

Results: All patients in the two groups were followed up 12-26 months, with an average of 15 months. There was no significant difference in the follow-up time between the closed group and the open group ( P>0.05). The operation time in the closed group was shorter than that in the open group, and the intraoperative fluoroscopy times, the fracture healing time, and the time of returning to work in the closed group were more than those in the open group, and the differences were significant ( P<0.05). In the closed group, there were 5 cases of pinning tract infection and 3 cases of small area pressure ulcer skin necrosis on the dorsal side of the finger, which were cured after intensive nursing and dressing change. Local nail depression deformity occurred in 7 cases in the open group, and the deformity disappeared after removal of plate. The incisions of the other patients healed uneventfully without complications such as infection, skin necrosis, exposure of the internal fixation, or nail deformity. There was no significant difference in the incidence of skin necrosis between the two groups ( P>0.05), but the differences in the incidence of infection and nail deformity between the two groups were significant ( P<0.05). There was no significant difference in VAS score, DIP active flexion range of motion, DIP extension deficiency, or Crawford criteria evaluation between the two groups at 12 months after operation ( P>0.05). At last follow-up, there was no DIP osteoarthritis and joint degeneration in both groups.

Conclusion: Open reduction and hook plate fixation versus closed indirect reduction and dorsal extension blocking Kirschner wire fixation have their own advantages and disadvantages, but both of them have good results in the treatment of bony mallet fingers. Open reduction and hook plate fixation is recommended for young patients with bony mallet fingers who are eager to return to work.