Wrist-Activated Functional Hand Prosthesis

FRANCIS J. TROST, MD* AND ANN MARIE FARLEY, CPGolden Valley, Minnesota


Because of problems with patient acceptance of the partial hand and the prosthetic devices available for the below-wrist amputee, a wrist-activated functional hand prosthesis was developed. The prosthesis, which was adapted from a prototype incorporates a socket, a functional hand and a cosmetic glove. The hand operates by flexion and extension of the residual carpal (and metacarpal, if present) elements of the amputation limb. Such action opposes the index and middle fingers of the prosthetic hand to the thumb. The prosthesis is lightweight, aesthetically pleasing, easily donned and eliminates harnessing.

Eleven children at the Twin Cities Unit of Shriners Hospital have been fitted with the prosthesis. Seven amputees are using it, while four have rejected it. Problems with suspension and terminal-device extension are being reduced with further development.

The initial design employing rigid hinges incorporated into plastic laminate at the wrist has evolved successfully to a flexible silicon socket. The improvement allows full range of motion in all directions while providing the security of suction suspension. Rigid individual finger pieces, housed in an inlet passive prosthetic hand, are riveted to the socket. A cosmetic glove is pulled over the prosthesis for attractive appearance.

Every component of the prosthesis is modular in design, thus allowing disassembly for replacement of integral parts and accommodation of changes due to growth.

Experience with function and patient acceptance to date stimulates hope for promising long-term results with the new prosthesis.

*2545 Chicago Avenue, Suite 301, Minneapolis, MN 55404