Radiography and visual pathology of the osteoarthritic scaphotrapezio-trapezoidal joint, and its relationship to trapeziometacarpal osteoarthritis

PURPOSE: To determine and quantify the relationship of osteoarthritis (OA) in the trapeziometacarpal, scaphotrapezial, and scaphotrapezoidal joints; to ascertain the dependability of radiographic assessment of trapeziometacarpal, scaphotrapezial, and scaphotrapezoidal OA; to determine the articular topography of the scaphotrapezio-trapezoidal (STT) joint (composed of the scaphotrapezial and scaphotrapezoidal articulations) using stereophotogrammetry; and to characterize the articular wear patterns of STT OA. METHODS: Sixty-nine fresh-frozen human cadaveric hands were staged radiographically and by gross visual examination for the presence of OA in the trapeziometacarpal and STT joints. Twenty randomly selected joints also were evaluated to determine the topography of the STT joint using stereophotogrammetry. RESULTS: Concomitant severe osteoarthritic degeneration was found in the trapeziometacarpal and STT joint in 60% of our specimens. A correlation was found in the severity of OA in the trapeziometacarpal and STT joints. Radiographic and gross visual evaluation of STT OA concurred in 39% of our specimens. CONCLUSIONS: The prevalence of concomitant trapeziometacarpal and STT OA, and the uncertainty of radiographic evaluation of STT OA, indicate the need to visualize the STT joint intraoperatively to determine the true degree of degenerative changes present.