Conservative treatment versus percutaneous intramedullary pinning for acute tendinous mallet finger: Does pin configuration matter?

BACKGROUND

Acute tendinous mallet finger (Doyle type I) is commonly treated with continuous immobilization of the distal interphalangeal (DIP) joint; however, treatment success largely depends on patient compliance. Percutaneous intramedullary (IM) Kirschner wire DIP joint transfixation represents a minimally invasive surgical alternative, although the clinical relevance of different pin configurations remains unclear. This study compared conservative and surgical treatment methods and evaluated the impact of different pin configurations on clinical outcomes.

METHODS

This retrospective cohort study included 93 adult patients with acute tendinous mallet finger who presented within 7 days of injury and were followed for at least 12 months. Patients were allocated into three groups: conservative treatment with a tape-reinforced Stack splint (n=33), percutaneous IM Kirschner wire DIP joint transfixation with the pin left exposed (n=30), and IM transfixation with the pin buried within the fingertip pulp (n=30). The primary outcome was residual DIP joint extension lag at final follow-up. Secondary outcomes included functional results according to the Crawford criteria and treatment-related complications.

RESULTS

Baseline DIP extension lag did not differ significantly among the groups (p=0.801). At final follow-up, residual extension lag was significantly greater in the conservative group (median 4°) compared with the surgical groups (0.5° and 1°, respectively; p<0.001). Multicategorical analysis of Crawford grades showed no significant intergroup difference (p=0.095); however, dichotomous analysis (excellent + good outcomes) demonstrated significantly higher success rates in the surgically treated groups compared with the con-servative group (p=0.014). Skin maceration was more frequent in the conservative group (p<0.001), whereas pin-site irritation was significantly more common in the exposed pin group (p=0.006). No significant differences were observed among the groups regarding superficial infection.

CONCLUSION

In patients with acute tendinous mallet finger, percutaneous IM Kirschner wire DIP joint transfixation provides superior extension control and higher functional success rates compared with conservative treatment. Although pin configuration does not significantly influence functional outcomes, it affects patient comfort and the complication profile. Treatment decisions should therefore be individualized based on patient compliance and functional expectations.