Pathologic conditions of the pisiform and pisotriquetral joint.

In eight of sixteen patients with symptomatic pisotriquetral joints the pisiform was excised. A detailed study allowed correlation of the etiologic factors with the pathologic diagnosis. In a similar fashion pathologic-etiologic data were retrieved from 216 cases identified from the world literature and organized into the following four pathologic groups: primary OA (2.3%), secondary OA (48.4%), other arthritides (4.7%), and flexor carpi ulnaris enthesopathy (44.6%). The most common causes were acute and chronic trauma and instability. On the basis of these data, we hypothesized that loss of integrity to the surrounding retinacular structures of the pisiform may lead to instability and thus dysfunction of the joint.