Cemented and Cementless Femoral Stem Fixation in Thr for Patients Aged 75 Years and Older: A Comparison of the Best Performing Stems in this Age Group

Introduction There is ongoing debate concerning the best method of femoral fixation in older patients receiving primary total hip replacement (THR). Arthroplasty registry studies universally report that cementless stems are associated with a higher rate of revision in this patient population. A criticism of registry studies is that they do not take into account individual prosthesis variation. The aim of this study was to address this issue by using the Australian Joint Registry to compare the best 3 stems in each fixation group in patients aged 75 years or older.

Methods The best 3 cemented and cementless femoral stems were selected using the criteria of being used in more than 1000 procedures in this age group and having the lowest cumulative percent revision at 10 years. The combination of the best 3 prostheses were used to compare cemented and cementless stems. The principal outcome measure was time to first revision using Kaplan-Meier estimates of survivorship. Comparisons were made for THR’s undertaken for any diagnosis then osteoarthritis and fractured neck of femur separately. Reasons for revision and type of revision were also determined.

Results When analysis for all primary diagnosis was undertaken cemented femoral stem fixation had a lower rate of revision. This however was only evident for the first 6 months with the difference being greatest in the first month (0-1 Month HR=2.73 (2.04, 3.65) p

Conclusion Cementless femoral stem fixation in patients older that 75 years old is associated with a higher earlier rate of revision even when only the best performed prostheses in this age group are compared. The difference is much greater when THR is used for fractured neck of femur.