Introducing the “SOAC Wrist”: Scaphotrapeziotrapezoid Osteoarthritis Advanced Collapse

Abstract

AbstractDespite being the second most common osteoarthritis of the wrist, little is known about scaphotrapeziotrapezoid osteoarthritis. Not all patients with this type of osteoarthritis have symptoms, and, even in those symptomatic patients, the intensity of the complaint is not proportional to the severity of the degeneration. In symptomatic patients, when the conservative treatment fails, grading classifications to help define the surgical treatment are solely based on the joint characteristics, and fail to assess the rest of the carpus.In general, most carpal degenerative processes show the same evolution pattern, which varies according to the initial injury, along with the type of deformity and the inherent instabilities. Thus, we hypothesize that the degenerative evolution due to primary osteoarthritis of the scaphotrapeziotrapezoid joint also follows a logical evolutionary sequence, similar to the one that occurs in cases of scapholunate advanced collapse (SLAC), scaphoid nonunion advanced collapse (SNAC), scaphoid malunion advanced collapse (SMAC), and scaphoid chondrocalcinosis advanced collapse (SCAC), thus resulting in scaphotrapeziotrapezoid osteoarthritis advanced collapse (SOAC). We have divided the SOAC into three groups, and considered that their treatment shall be guided by the evolutionary stage of the disease, and not by the surgeon's preferred technique.