The classification and treatment of Kienbock's disease: the state of the art and a look at the future.

The proper treatment of Kienböck's disease, a disorder that displays slow progression with eventual collapse of the lunate and alteration of the surrounding carpal architecture, requires an understanding of its aetiology and natural history. A reproducible classification system assists the surgeon in making appropriate treatment choices. In this discussion, we review the history and rationale for the four-stage step-wise classification system, along with our current treatment algorithm. We also discuss emerging classification systems and speculate on future directions in treatment and research.