Risk factors for recurrent aseptic loosening of the femoral component after cemented revision.

A series of 160 consecutive cemented first revisions, performed from 1977 through 1988 for aseptic loosening of a primary cemented femoral component, were studied using survivorship methods with the purpose of identifying risk factors for recurrent loosening of the femoral component. Risk of recurrent loosening depended on the length of the revision stem, with a significantly increased risk of loosening if the tip of the primary stem was overbridged by the revision stem with less than one width of the femoral shaft. Risk of recurrent loosening was also related to the extension of a cement mantle, exceeding more than 2 mm, around the revision stem measured on postrevision anteroposterior radiographs. Furthermore, low age and neutral position of the revision stem were identified as risk factors for recurrent loosening of the cemented revision femoral component. An improved fixation of the cemented revision femoral component for revisions performed after 1982 could be related to the use of longer revision stems and improved cementation.