An adjustable and customised finger splint to improve mallet finger treatment compliance and outcomes

Objective

Tendinous mallet finger injuries are normally treated conservatively by finger splinting, whereby the injured finger is immobilised in extension to allow the ruptured extensor tendon to heal. However, current splints including the Stack and Zimmer reported high failure rates of almost 50 %. Reasons are attributed to poor splint fit, skin complications and discomfort which cause non-compliance to splint regimens. To address the above mentioned issues, we designed and developed a 3D printed adjustable and customised finger splint.

Participants and interventions

The 3D printed finger splint, Zimmer and Stack splint were worn by 24 healthy volunteers on their middle fingers for 24 h.

Main outcome measures

The finger extension angle, splint fit, splint comfort and skin maceration were assessed via angle measurement and subjects’ feedback using a questionnaire.

Results

The 3D printed finger splint was capable to maintain the distal interphalangeal joint at an extended angle of 8.1° However, 70.8 % of the subjects reported that the 3D printed finger splint shifted or came off wholly during 24 h of wear. This proportion is higher compared to the Zimmer (45.8 %) and the Stack (37.5 %). While 91.7 % of the subjects were satisfied with the ease of wearing and removing the 3D printed finger splint, subjects experienced difficulty performing work and washing activities owing to the design and material.

Conclusion

Our proposed design fulfils its function of holding the fingertip in extension and improves ease of application. The design of 3D printed finger splint could be further refined to provide better splint fit and comfort, so as to achieve better treatment compliance.