1 Barwon Health and Deakin University, Geelong, Australia; Australian Orthopaedic Association National Joint Replacement Registry, Adelaide, Australia. Electronic address: richardpage@geelongortho.com.au.
2 Southern California Permanente Medical Group, Kaiser Permanente Shoulder Arthroplasty Registry, Harbor City, CA, USA.
3 Department of Orthopedics, Karolinska Institutet Danderyds Sjukhus AB, Stockholm, Sweden.