Inter-relationship between radiocarpal and metacarpophalangeal joint deformities in rheumatoid arthritis.

The roentgen evaluation of 96 rheumatoid hands and wrists, supplemented with anatomic and pathologic material from cadavers and patients with rheumatoid arthritis, allowed evaluation of deformities at the radiocarpal and metacarpophalangeal articulations. Measurements of specific coordinates in these patients were compared to those in "controls" and, despite significant error introduced by variability in patient positioning during radiography, definite inter-relationships between radiocarpal and metacarpophalangeal malalignments became evident. Radial deviation at the wrist was associated with ulnar deviation of the digits producing the "zig-zig" deformity of the rheumatoid hand. The pathogenetic and therapeutic aspects of the roentgen findings are discussed.