Extensor indicis proprius transfer for rupture of the extensor pollicis longus tendon.

We reviewed 21 patients with 22 ruptures of the extensor pollicis longus at a mean of 5.3 years after transfer of the extensor indicis proprius tendon. Of these, 19 with 21 transfers described the result as good, and two as fair. The mean deficit of extension between the operated and unoperated thumbs was 1.4 cm, and the mean flexion deficit 0.6 cm. Pressure gauge measurements showed that the strength of the transfer was 51% of that of the uninjured extensor. The two fair results had an extensor lag of over 1.5 cm. Independent extension of the index was maintained in all patients, none having a discernible lag, but the strength of index extension was reduced to 49% of that of the normal finger. There was no evidence of functional loss. Extensor indicis proprius transfer for rupture of the extensor pollicis longus tendon is a simple and reliable procedure with few complications. It gives satisfactory long-term extension of the thumb.