The STT joint was examined in 73 fresh cadaveric specimens (25 male and 48 female with an average age of 84 years) with a view to study the incidence and characteristics of degenerative changes in this joint. The articular degeneration was graded from 0 to 3 according to increasing loss of cartilage and the location of the changes was noted. At the same time, the presence and extent of concomitant trapezio-metacarpal arthritis was noted. 61 of the 73 hands (83.3%) were found to present STT arthritis. Degeneration of the trapezoid articular surface was:- more frequent: 53 hands (72.6%) as compared to 48 (65.7%),-of greater severity: 40 cases (55%) of grades 2/3 as compared to 25 (34%), than that of the trapezium. Concomitant or isolated arthritis in the trapezometacarpal joint (90.4%) was present in 66 of the 73 hands (79%) examined with grade 3 changes in 13 cases. The apparent predominance of degeneration in the scapho trapezoidal articulation could, perhaps, lead us to assume that this might be the site of origin of STT arthritis. It could also explain the persistence of symptoms following prosthetic replacement of the trapezium.