[The traumatic boutonnière deformity].

The traumatic boutonnière (or buttonhole) deformity develops after unsuccessful primary treatment of a lesion of the extensor tendon at the level of the proximal interphalangeal joint. Knowledge of the mechanisms leading to this deformity is fundamental for choosing and executing reconstructive procedures. The most frequently used methods are illustrated in this article. Because none of these procedures has been shown to be successful in all situations, we recommend a staged reconstructive approach. Even then, this deformity often results in incomplete reconstruction. Therefore, for these lesions especially, correct primary diagnostics and repair are required.