Abstract
The survivorship of sockets after 267 Charnley low-friction arthroplasties was studied with follow-up periods of 5 to 18 years. The end point of survivorship was defined in two ways : as incipient failure and as definite failure. When a socket migrated more than 2 millimeters or rotated more than 2 degrees from its original position just after surgery but there was no need for revision, the socket was judged to have developed incipient failure. Definite failure was indicated by the necessity for revision due to aseptic loosening of a socket. Twelve variables (age, sex, diagnosis, Charnley's categories, obesity index, socket-fixation method, socket design, socket angle, bony acetabular angle, socket height, socket wear at five years and stem subsidence) were investigated to assess socket survivorship by the Kaplan -Meier method.
In the present series, 24 sockets developed incipient failure and 14 of them developed into definite failure. Socket-fixation method, socket design, socket angle, and socket wear at five years was correlated with the development of incipient failure. Only socket wear at five years was correlated with the development of definite failure.
