Functional Outcomes with Externally Powered Partial Hand Prostheses

Abstract

ABSTRACT Introduction Despite the large number of individuals experiencing partial hand limb loss or deficiency, and the impact of this level of loss on hand function, there is minimal research available regarding the benefit of partial hand externally powered prostheses. The purpose of this research was to explore how using an externally powered partial hand prosthesis contributes to the completion of functional tasks. Materials and Methods Fifteen individuals being fit with i-digits partial hand prostheses were evaluated using the Southampton Hand Assessment Procedure (SHAP) and Patient-Specific Functional Scale (PSFS). The individuals were each fit during a 1-week condensed fitting and training process and received 10 to 15 hours of therapy between the prefitting and postfitting testing. Results Twelve male and three female clients with four- (with thumb remaining) or five-digit partial hand limb loss or deficiency participated. Average age was 42 years, and 87% had acquired amputations an average of 2.44 years before the fitting. All subjects demonstrated clinically significant change scores on both the PSFS and the SHAP. The individuals with five-digit absence demonstrated marked improvement in comparison with those with four-digit absence; however, both were far superior to the minimal detectable change score for the SHAP, with 42.33 and 19.16 average improvement scores, respectively. Conclusions Subjects fit with four- or five-digit externally powered partial hand prostheses demonstrated significant functional improvements in objective hand function and individualized goals. The remnant thumbs of users fit with four-digit systems sometimes exhibited limitations on range of motion or strength. Despite this, their evaluation scores still showed significant improvement; in fact, almost 10 times the minimal detectable change score. For those with five-digit absence, the change was 20 times the minimal threshold. These results suggest the benefit of the i-digits partial hand prosthesis as contributing to the function of individuals with partial hand limb loss or deficiency, particularly with the individuals' priority functional goals.