Arthrograms were performed on twenty-five metacarpo-scaphoid joints following excision of the trapezium. The joint space was initially irregular and of small capacity within six months of surgery, but became larger and smoother in time. Sometimes the joint space communicated directly with the midcarpal joint or the extensor pollicis longus strength. The arthrographic appearance did not provide an indication as to the clinical outcome, but marked subluxation of the first metacarpal on the scaphoid during abduction correlated with a less successful outcome.