Retrospective study of Ishiguro’s technique for mallet bone finger in children: long-term follow-up and analysis of predictors in outcomes

There is no consensus on the optimal treatment of bony mallet finger in the paediatric population due to a lack of studies in children. The Ishiguro technique is simple and less invasive, and treatment with K-wire fixation seems to provide better results for extension lag in bony mallet finger according to the literature. A retrospective cross-sectional study with long-term follow-up was performed to evaluate the functional and clinical outcomes of this method in children. Preoperative and intraoperative predictors of outcome were investigated.

From June to December 2022, we evaluated 95 children who underwent extension K-wire block from 2002 to 2012. Eighty-four children were included (mean age 14.8 ± 1.68 years) for a mean long-term follow-up of 11.6 ± 2.3 (8–16) years. Clinical and radiographic features were assessed. Pain and functional outcomes were assessed using Crawford criteria, range of motion (ROM) at the distal interphalangeal joint (DIPJ), loss of extension, and VAS scale. Univariate and multivariate regressions were used to assess which variables might predict the worst outcomes at long-term follow-up.

Bone union and pain relief were always achieved. There were no complaints of potential growth impairment or nail deformity. 82.1% of patients showed excellent and good results. Fifteen patients had fair results.

Although there are currently no significant differences between surgery and orthosis in adults, the Ishiguro technique is more effective in children when it comes to outcomes in the treatment of mallet fingers. A high percentage of excellent and good results were achieved, and no epiphyseal damage or nail deformity was reported. A strong and significant correlation was found between the worst outcomes and either delayed treatment time or excessive flexion angle.