Lunate morphology: can it be predicted with routine x-ray films?

To assess our ability to predict lunate morphology, x-ray films of 81 cadaver wrists were obtained. The wrists were then dissected to determine true anatomy, specifically the presence or absence of a medial lunate facet. Thirty-five wrists were found to be type 1 lunates, while 46 were type 2. Cartilage erosion at the proximal pole of the hamate was found in association with 28 of the type 2 lunates. The accuracy of determining lunate morphology ranged from 64% to 72%. Therefore, lunate morphology cannot always be reliably predicted by a standard x-ray film. Arthrosis at the lunate-hamate articulation is frequent in association with type 2 lunates.