Stress shielding resulting in diminished bone density following total knee replacement (TKR) may increase the risk of migration and loosening of the prosthesis. This retrospective study was designed to quantify the effects of the method of fixation on peri-prosthetic tibial bone density beneath cemented and uncemented tibial components of similar design and with similar long-term survival rates. Standard radiographs taken between two months and 15 years post-operatively were digitised from a matched group of TKRs using cemented (n = 67) and uncemented (n = 67) AGC tibial prostheses. Digital radiograph densitometry was used to quantify changes in bone density over time. Age, length of follow-up, gender, body mass index and alignment each significantly influenced the long-term pattern of peri-prosthetic bone density. Similar long-term changes in density irrespective of the method of fixation correlated well with the high rate of survival of this TKR at 20 years, and suggest that cemented and uncemented fixation are both equally viable.
Cite this article: Bone Joint J 2013;95-B:911–16.
The authors would like to thank T. L. Apple for her contributions to the data analysis in this study. Institutional support unrelated to this article is received from Biomet, Inc., DePuy, Inc., ERMI, Inc., Stryker, Inc., and Franciscan St. Francis Hospital – Mooresville.
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
This article was primary edited by D. Rowley and first-proof edited by J. Scott.
- Received July 30, 2012.
- Accepted February 19, 2013.
- ©2013 The British Editorial Society of Bone & Joint Surgery