51. CEMENTED AND CEMENTLESS TOTAL HIP ARTHROPLASTY: RESULTS OF A RANDOMISED CONTROLLED TRIAL AT 17 TO 21 YEARS FOLLOW-UP

Abstract

Purpose: A randomised controlled trial comparing fixation of a Mallory-Head prosthesis for total hip arthroplasty (THA) with and without cement was performed with average 19 years (range 17–21 years) of continuous follow-up.

Method: Two hundred and fifty patients were randomised to undergo THA using either a Mallory-Head THA prosthesis designed to be inserted with cement or one designed for cementless insertion. Both patients and those involved in outcome assessment were blinded to the type of implantation. Patients were followed yearly after the first post-operative year for outcomes including mortality, revision arthroplasty, and health-related quality of life assessment scores.

Results: Primary THA was performed with cement in 124 patients and without cement in 126 patients. Mean age at the time of surgery was 64 years, and 48% were female. During the period of review, there were 78 (31%) deaths in the cohort, and 75 (30%) patients underwent revision surgery. Kaplan-Meier survivorship analysis revealed significantly increased revision rates in cemented compared with cementless THA using failure of either component (p=0.01) or femoral component (p< 0.001) as endpoints. Although acetabular failure accounted for most revisions overall, no significant difference between groups was noted (p=0.075). With the exception of cost to quality adjusted life years, all quality of life outcome measures improved post-operatively and, although reducing modestly through the period of review, demonstrated no difference between groups at final follow-up.

Conclusion: This study has demonstrated a concerning high revision rate with both cemented and cementless THA in patients with a mean age of 64 years at the time of surgery, which significantly affected cost effectiveness. With the implants studied, cementless femoral fixation was superior to cemented, with no cementless femoral component failures through the duration of this study. This study demonstrates the importance of post-market surveillance and evidence-based improvements in THA design (i.e., bearing couples and fixation).