Trabecular Metal Acetabular Components Reduce the Risk of Revision Following Primary Total Hip Arthroplasty: A Propensity Score Matched Study From the National Joint Registry for England and Wales

Abstract

Background Trabecular metal (TM) coated acetabular components are increasingly used in both primary and revision total hip arthroplasty (THA). However, previous studies assessing TM acetabular components have been small single-centre cohorts with most lacking a control group. We compared revision rates following primary THA between TM and non-TM coated acetabular components. Methods A retrospective observational study was performed using National Joint Registry data, which included primary THAs with the same cementless acetabular component (either TM or non-TM coated). TM and non-TM implants were matched for multiple potential confounding factors using propensity scores. Outcomes following primary THA (revision for all-cause acetabular indications, aseptic acetabular loosening, and infection) were compared between matched groups using competing risk regression analysis. Results In 18,200 primary THAs (9,100 TM and 9,100 non-TM), the overall prevalence of acetabular revision, revision for aseptic acetabular loosening, and septic revision was 1.2%, 0.13%, and 0.59% respectively. Five-year revision rates for all-causes (1.0% vs. 1.8%; sub-hazard ratio *Abstract (Structured; 250 Words Maximum) (SHR)=0.57, 95% CI=0.43-0.76; p<0.001), aseptic acetabular loosening (0.1% vs. 0.2%; SHR=0.35, CI=0.14-0.90; p=0.029), and infection (0.5% vs. 0.9%; SHR=0.51, CI=0.34-0.76; p=0.001) were all lower in TM compared with non-TM implants. Conclusion Following primary THA, TM coated implants had a reduced risk of both aseptic and septic revision compared with non-TM implants. Although absolute differences in revision risk were small, they may be clinically significant if TM designs were implanted in more complex cases.

Do Trabecular Metal Acetabular Components Reduce the Risk of Rerevision After Revision THA Performed for Periprosthetic Joint Infection? A Study Using the NJR Data Set

“…Three registry studies have subsequently assessed the effect of TM on future infection [8,9,11]. In the NJR for England and Wales we earlier reported lower revision rates for infection when TM (versus non-TM) was used in primary THA [9], but no difference in re-revision rates for infection when TM was used for all-cause revision THAs [11]. The latter findings in allcause revisions were also confirmed in a study from the Swedish and Australian registries [8].…”

“…It was suggested that TM was protective against infection after revision, and that TM may be useful when revising THAs for PJI. Three registry studies have subsequently assessed the effect of TM on future infection [8,9,11]. In the NJR for England and Wales we earlier reported lower revision rates for infection when TM (versus non-TM) was used in primary THA [9], but no difference in re-revision rates for infection when TM was used for all-cause revision THAs [11].…”

“…After revision THA performed for PJI, TM acetabular components had a risk of all-cause rerevision, which was comparable to non-TM components in the present study. The perceived advantages of TM acetabular components have led to an increase in their use worldwide for both primary and revision THA [8,9,11]. A small study of 46 revision THAs for all causes in which TM components were used reported a 96% survival rate for the acetabular component at 11 years with excellent pain relief and good functional outcomes observed in patients with surviving implants [6].…”

“…for England and Wales we earlier reported lower revision rates for infection when TM (versus non-TM) was used in 18,200 primary THAs though this was of questionable clinical importance [9]. Using the same registry we also earlier reported no difference in re-revision rates for infection when TM (versus non-TM) was used for 3,862 all-cause revision THAs [11].…”

“…It was suggested that TM was protective against infection after revision, and that TM may be useful when revising THAs for PJI. Three registry studies have since assessed the effect of TM on the risk of subsequent revision for infection [8,9,11]. In the National Joint Registry (NJR)…”