Long-term results of nail fusion plasty of the duplicated thumb.

We report the long-term results of nail fusion plasty in eight duplicated thumbs. These eight cases were hypoplastic, with nails less than 80% the size of that on the normal side. We operated on these duplicated thumbs using a technique that we developed. We evaluated postoperative nail shape in our series using both our and Tada's scoring systems. The average follow-up period was 12 years. Excellent results were obtained in six cases, with natural-looking nails and even curvature. One case showed acceptable results. Only one case had uneven curvature and a gap in the nail. To reconstruct a natural-looking nail, it is important to correctly design and suture together two nails under no tension. To obtain one nail with even curvature, bones are left floating so that the nail can grow with a natural transverse curve without interference. This technique yielded promising results on long-term follow-up.