The technique and advantages of synovectomy of the interphalangeal joints of the fingers and thumb and of the metacarpophalangeal joint of the latter digit, whereby the joints are dislocated at operation, have been described. The same surgical approach may be used for arthroplasty, which is occasionally indicated for these joints. It also may be used for arthrodesis of the joints. The technique, as observed in 136 instances, appears to be far superior to the two-incision technique whereby the joints are not dislocated.