Percutaneous Kirschner-wire fixation followed by an opencast to permit protected daily and sports activities in patients with tendinous mallet finger: a case series at a tertiary hospital in Korea

Background: Dong-A University Hospital’s protocol for tendinous mallet finger requires 12 weeks of continuous full-time distal interphalangeal (DIP) joint splinting, which may restrict activities and complicate hygiene. This study evaluated the feasibility, short-term safety, and 6-month clinical outcomes of buried Kirschner-wire fixation followed by opencast application.Methods: This retrospective case series screened 36 patients with mallet finger between January 2024 and October 2025. Twelve met the exclusion criteria, leaving 24 eligible patients; eight elected nonoperative treatment, and 16 chose surgery for acute closed tendinous mallet finger and constituted the study cohort. The DIP joint was fixed in approximately 15° of hyperextension using one or two buried 1.1-mm Kirschner wires. An opencast was applied at 1 week. The wires were routinely removed and active motion was initiated at 8 weeks, followed by a removable brace during outdoor or sports activities for 4 weeks. Outcomes were evaluated at 6 months.Results: The mean preoperative extension lag was 30.0°. At 6 months, the mean residual extension lag was 1.9°, no flexion loss was observed, and Crawford outcomes were excellent in 62.5% and good in 37.5%. Two superficial pin-site infections resolved with oral antibiotics and local wound care. A separate case of wire loosening with painful subcutaneous prominence was managed with an aluminum splint. All patients resumed daily activities and showering at 1 week, when protected sports were also permitted; exact return dates and activity intensity were not recorded.Conclusions: Buried Kirschner-wire fixation followed by opencast application may be an option for selected patients who wish to avoid prolonged full-time splinting. The protocol permitted protected activities from week 1 and active DIP motion from week 8; these findings support its feasibility but do not establish earlier return to unrestricted activity.Level of evidence: IV.