Assessing Rotational Deformity of the Little Finger

Abstract

Excessive scissoring or overlap of fingers can cause discomfort, weaken grip strength, and affect cosmesis. The treatment of little finger fractures is guided by the degree of scissoring or rotational deformity perceived in the digit. The purpose of this study is to assess the variation of little finger scissoring or overlap in the normal population using standard clinical examination. We evaluated 80 uninjured little fingers in 40 normal patients. The digital images of photographed hands, taken in both extension and flexion, were used to evaluate the overlap percentage of the adjacent fingernail as a proxy for rotation of the digits. Paired t tests were used for statistical analysis. The average fingernail overlap was 25% ± 20%, ranging from 0% to 71%. The average overlap on the left hand was significantly less at 21% ± 18% as compared to 30% ± 21% on the right (P < .01). The average variation between hands in individuals was 16% ± 13%.This study confirms that overlap or scissoring of the little finger varies between the hands of a given individual. Our results question the usefulness of assessing rotational deformity of the little finger by checking for overlap and comparing with the contralateral side. This has implications not only in assessing patients for possible surgery, but also in planning and performing surgical reductions of acute fractures and for correction of malunions.