Cemented and hybrid fixation seem to be most cost-effective in total hip arthroplasty

Abstract

Cemented and hybrid fixation appear to be the most cost-effective modes of fixation in total hip arthroplasty (THA), according to findings of a systematic review published in Expert Review of Pharmacoeconomics and Outcomes Research. Medline, EMBASE, EconLit, the Web of Science, and the Cochrance Central Register of Controlled Trials databases were searched for studies reporting the cost effectiveness, cost-benefit or other economic evaluations of cemented, cementless, hybrid (cemented stem and cementless cup) and reverse hybrid (cementelss stem and cemented cup) fixation modes in THA, which were published between 1994 and February 2020. Overall, 12 identified studies met the inclusion criteria for systematic review; five of these met the two selection criteria for evaluating the cost effectiveness of implant fixation modes in gender and age groups based on high quality studies: (i) Quality of Health Economic Studies (QHES) score ≥75 (high quality); and (ii) time horizon of 10 years or longer. Cost-effectiveness analyses (CEAs) were based on willingness-to-pay thresholds of €20 000, £20 000 [British pounds] or $25 000 [US dollars] per QALY gained. Of the five high-quality studies included in the analysis, an analysis in adults 30–90 years of age found that cementless fixation was dominant (more effective and less costly) compared with hybrid fixation in patients up to 40 years of age, while estimated incremental cost-effectiveness ratios (ICERs) for cementless fixation increased from €22 to €87 839 per revision-free life-year in patients aged 45–80 years. Hybrid fixation was dominant in patients 85 years of age or older. A second study comparing cemented, cementless and hybrid fixation, with stratification by age and sex, found that hybrid fixation was cost effective versus cemented fixation in men in all age groups, with ICERs of £2083–£4138 per QALY gained, and in women aged 60 and 70 years, with ICERs of £2966 and £2496 per QALY gained, respectively, but cemented fixation was dominant in women aged 80 years. In another study comparing the same three fixation modes in patients stratified by age and sex, cemented fixation was dominant compared with cementless and hybrid fixation in all age groups in men and women. A study comparing these three fixation modes in patients 70 years of age found that the most frequent implant combination (reference implant combination) was the Corail stem and Pinnacle acetabular component. The top three implants based on incremental net monetary benefit (INMB) were: CPT Trilogy (hybrid; INMB £954 and £876 in men and women, respectively); Exeter V40 Trident (hybrid; INMB £344 and £71, respectively); and Corail Pinnacle (cementless; reference implant [INMB £0]). Finally, a study comparing cemented, cementless, hybrid and reverse hybrid fixation modes assessed 24 implant combinations subdivided based on bearing surface and head size (<36mm [small] vs ≥36mm [large]). The reference implant combination was a cemented metal-on-polyethylene implant with small head combination, which was ranked first in men and women over 65 years of age (INMB £0). Cemented implants with ceramic-on-polyethylene bearing and a small head had the highest INMB values in men and women aged under 55 years (INMB £1163 and £823, respectively) and those 55–64 years of age (£514 and £104, respectively.) Currently available high-quality cost-effectiveness studies on the optimal implant fixation mode in THA suggest hybrid or cemented fixation to be the most cost-effective for most age groups and both genders. Cementless fixation as the main mode of fixation is therefore not supported by currently available CEAs, concluded the authors. However, the number of available studies on this topic is limited and particularly based on a single national arthroplasty registry, which complicates the transferability of results to other healthcare systems. Future work is therefore much needed. Currently, cost-effectiveness studies should not be the only evidence to consider when choosing a certain implant fixation mode in clinical practice, they added.