[Piso-triquetral arthrosis and the so-called pisiform secundarium]

After scapho-trapezial osteoarthritis, piso-triquetral is the next most common. Some of the various changes of the piso-triquetral osteoarthritis are also to be seen in the dorso-volar view. The so-called secondary pisiform is not a congenital variant but develops with increasing frequency in older age as one of the features of the osteoarthritic reactions.