62. MORTALITY FOLLOWING CEMENTED AND UNCEMENTED HEMIARTHROPLASTY

Abstract

Purpose: The appropriate means of fixation for hemiarthroplasty of the hip is a matter of ongoing debate. Proponents of uncemented components cite the risk of perioperative mortality with cement implantation as justification for avoiding cement in certain patients. Because cement-related mortality is rare, we wished to compare the incidence of perioperative mortality in patients receiving cemented versus uncemented hemiarthroplasty using a large national database. Further, we wished to compare overall revision rate between fixation methods to assess their role in implant survivorship.

Method: All recorded hemiarthroplasty cases from the AOA National Joint Replacement Registry were cross-referenced to the Australian mortality data, and deaths at 1d, 7d, 28d, and one year were compared between groups. Further, subgroup analysis of monoblock, modular, and bipolar hemiarthroplasty were compared as a surrogate measure of different patient populations.

Results: Comparing all hemiarthroplasty procedures as a group, there was a a significantly increased mortality rate at day one post-operatively (p = 0.0005) when cement was used. By day 7, this trend reversed, revealing a reduced mortality risk with cement (p = 0.02). This trend reversal persisted at day 28 and one year post-operatively (p = 0.028 & p < 0.0001, respectively). With subgroup analysis, monoblock hemiarthroplasty revealed a similar trend reversal in early versus late mortality. Modular and bipolar hemiarthroplasty procedures failed to reveal a significant difference in mortality when cemented and uncemented components were compared at all time points. When fixation method was compared in different age groups, a favourable mortality rate was seen at one year when cemented monoblock components were used in patients aged 71–80, and in patients ≥81 years old (p = 0.005 & < 0.001, respectively). The opposite was true with cemented modular implants at one year in patients < 70 years old (p = 0.009). There was no significant difference in mortality between cemented and uncemented implants in any other age investigated. Revision rates were significantly higher in patients treated with uncemented hemiarthroplasty regardless of prosthesis type.

Conclusion: This study demonstrates a higher overall success rate, and comparable or reduced long-term mortality risk when cement is used in hip hemiarthroplasty.