gms | German Medical Science

Clinical issue/s: Historically, the initial post-operative splint for Metacarpophalangeal Joint (MCPJ) Arthroplasty is a dynamic extension splint. Despite advances in technology and surgical techniques, there has been no innovation in splint design. Difficulties with this splint include: high outrigger necessitating inclusion of the wrist for splint stability, passive extension restricting active extensor tendon glide, pressure dorsally over the surgical site, finger rotation and need for night static splint.

Clinical reasoning: The only alternative identified in a literature review was static splinting which inhibits functional hand use for 6 weeks.

Our team aimed to develop an innovative splint that would meet the following goals:

1.

Allow early motion to maximize MCPJ flexion/extension and prevent ulnar deviation.

2.

Protect the joint capsule from ulnar forces during the encapsulation process.

3.

Protect the radial sagittal band by limiting flexion of MCPJ

4.

Economical, durable and easily fabricated

5.

Adjustable design to allow for day and nighttime use.

Innovative, analytical or new approach: We felt these goals could be accomplished by developing a splint with a small adjustable hinge that could restrict motion in the desired limits while protecting against ulnar deviation. Traditional hinges are metal, too large for finger use and expensive. We partnered with a manufacturing company to design a plastic, 3D printed hinge in a size suitable for MCPJ. This eliminates the need for outriggers, allows for a hand-based design, and eliminates dorsal pressure and rotation forces. The hinges can limit flexion and maintain full extension of MCPJ's at night. The materials to make the hinge are inexpensive and plastic, which easily attaches to thermoplastics.

Contribution to advancing HT practice: Use of a new technology, 3D printing, to fabricate splint designs previously not possible. Potential to change hinges currently used in hand therapy.

Potential for improved outcomes. A research study comparing the dynamic extension splint to our new design is underway.