The Exeter femoral stem is a double-tapered highly polished collarless cemented implant with good long-term clinical results. In order to determine why the stem functions well we have undertaken a long-term radiostereometric analysis (RSA) study.
A total of 20 patients undergoing primary Exeter total hip replacement for osteoarthritis using the Hardinge approach were recruited and followed with RSA for ten years. The stems progressively subsided and internally rotated with posterior head migration. The mean subsidence was 0.7 mm (95% confidence interval (CI) 0.5 to 0.9) at two years and 1.3 mm (95% CI 1.0 to 1.6) at ten years. The mean posterior migration of the head was 0.7 mm (95% CI 0.5 to 0.9) at two years and 1.2 mm (95% CI 1.0 to 1.4) at ten years. There was no significant cement restrictor migration.
The Exeter stem continues to subside slowly into the cement mantle in the long term. This appears to compress the cement and the cement bone interface, contributing to secure fixation in the long term.
Cite this article: Bone Joint J 2013;95-B:605–8.
The authors wish to thank Mrs B. Marks, Mr P. McLardy-Smith, Dr D. Simpson, Mr S. Glyn-Jones and the Research Radiographers at the Nuffield Orthopaedic Centre for their contributions to this study. Funding was received from Stryker (Newbury, United Kingdom).
Although none of the authors has received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article, benefits have been or will be received but will be directed solely to a research fund, foundation, educational institution, or other non-profit organisation with which one or more of the authors are associated.
This article was primary edited by G. Scott and first-proof edited by D. Rowley.
- Received November 20, 2012.
- Accepted January 16, 2013.
- ©2013 The British Editorial Society of Bone & Joint Surgery