Kienböck disease is a disorder of impaired lunate vascularity which ultimately has the potential to lead to marked degeneration of the wrist and impaired wrist function. The aetiology of the avascular necrosis is uncertain, but theories relate to ulnar variance, variability in lunate vascularity and intraosseous pressures. Clinical symptoms can be subtle and variable, requiring a high index of suspicion for the diagnosis. The Lichtmann classification has historically been used to guide management. We present a review of Kienböck disease, with a focus on the recent advances in assessment and treatment. Based on our understanding thus far of the pathoanatomy of Kienböck's disease, we are proposing a pathological staging system founded on the vascularity, osseous and chondral health of the lunate. We also propose an articular-based approach to treatment, with an arthroscopic grading system to guide management.