Wrist arthroscopy performed on 78 patients showed 35 lunates of Type I
(44.9%) i.e., having only one facet on their distal (midcarpal) aspec
t, and 45 lunates of Type II (55.1%), i.e., having two facets on this
aspect. Chondral defects and/or arthritic lesions of the ulnar portion
of the midcarpal joints were observed in 22.8% of Type I lunates and
in 30.2% of Type II lunates. Chondral lesions of the midcarpal joints
in Type I lunates were always associated with other ligamentous and/or
osteochondral lesions, whereas the same lesions could be found isolat
ed in Type II lunates. The observed association of lesions seemed to p
oint to a trauma as the cause of some chondral lesions. The results of
our clinical study were compared with anatomical studies by Viegas, a
ll which showed no hamate pathologic conditions in Type I lunates.