Abstract
Shoulder arthroplasty is a reliable procedure used to treat glenohumeral arthritis thanks to the efforts of many orthopaedic surgeons and design engineers over the past thirty years. Surgeons such Drs. Charles Neer and Robert Cofield were instrumental to making clinical observations that were effectively translated into improving implant design and clinical outcomes. Yet, there remains much room for further growth and development. With the increase numbers of shoulder arthroplasties performed, new observations and problems have been recognized that remain unanswered. ©2009 ASME.