Analysis of donor deficit after extensor indicis proprius tendon transfer

From November 1984 to February 1989, 13 extensor indicis proprius tendon transfers were performed for various reasons. Nine patients with a total of ten transfers were available for follow-up, at an average of 29 months. Active range of motion was measured (both dependently and independently) at the metacarpophalangeal joints of both the involved and the uninvolved index finger. There was no extensor lag of the metacarpophalangeal joint during dependent extension, and only an average of 2.1 degrees of extensor lag during independent extension. Measurement of total active motion showed that the dependent and independent range of motion of the involved index finger was 95% of that of the uninvolved index finger. The obvious concerns with using the extensor indicis proprius tendon for transfer is the possible theoretical loss of complete extension and independent extension of the index finger. We found these concerns not to be a problem.