Comparison of the risk of revision in cementless total hip arthroplasty with ceramic-on-ceramic and metal-on-polyethylene bearings

Abstract

Background and purpose Ceramic-on-ceramic (CoC) bearings were introduced in total hip arthroplasty (THA) to reduce problems related to polyethylene wear. We compared the 9-year revision risk for cementless CoC THA and for cementless metal-on-polyethylene (MoP) THA.Patients and methods In this prospective, population-based study from the Danish Hip Arthroplasty Registry, we identified all the primary cementless THAs that had been performed from 2002 through 2009 (n = 25,656). Of these, 1,773 THAs with CoC bearings and 9,323 THAs with MoP bearings were included in the study. To estimate the relative risk (RR) of revision, we used regression with the pseudo-value approach and treated death as a competing risk.Results 444 revisions were identified: 4.0% for CoC THA (71 of 1,773) and 4.0% for MoP THA (373 of 9,323). No statistically significant difference in the risk of revision for any reason was found for CoC and MoP bearings after 9 years of follow-up (adjusted RR = 1.3, 95% CI: 0.72–2.4). Revision rates due to component failure were 0.5% (n = 8) for CoC bearings and 0.1% (n = 6) for MoP bearings (p < 0.001). 6 patients with CoC bearings (0.34%) underwent revision due to ceramic fracture.Interpretation When compared to the “standard” MoP bearings, CoC THA had a 33% higher (though not statistically significantly higher) risk of revision for any reason at 9 years.

Do the Reasons for Ceramic-on-ceramic Revisions Differ From Other Bearings in Total Hip Arthroplasty?

“…This is an important finding because the time to revision of CoC THA was not mentioned in previous studies [27] or easy to extract from registries (the Australian register mentioned 2109 of 65,114 CoC THA revisions [3.2%] but not the revision rate before 5 years) [32]. Our results are in accordance with the Danish register indicating that 63 of 71 (88%) CoC THAs were revised before 5 years of followup [35]. This issue suggests that CoC THAs are technically demanding to use [26].…”

“…We cannot explain the higher rate of CoC THA revision because of infection (OR, 1.63 [1.12-2.37] versus MoP) despite this complication being mostly observed after large-diameter head MoM revisions [36]. Our study reported 39 of 238 revisions because of infection (16%), whereas the Danish hip register reports only 8% (six of 71) [35] and the Australian register less than 1% cumulative incidence revision because of infection at 10 years [32]. These infections were observed in our study despite the CoC population being younger and more active than the MoP group.…”

“…Historical data also suggest that the main reason for failure of CoC THA is cup loosening [12,29]. Little is known about CoC revisions from national registries: only 84 CoC hips are included in the Swedish hip registry [33] and only 71 CoC THA revisions are mentioned in the Danish register [35]. Although a large number of CoC bearings are included in the Australian registry, osteolysis and loosening are combined, confounding these two major issues [32].…”

The Danish Hip Arthroplasty Register

“…In 2015, four ongoing PhD students are using data from the DHR. They have identified the “true” incidence of prosthetic joint infection,11 described the epidemiology and outcome of fast track setting in Denmark,12 found that ceramic-on-ceramic does not have a greater risk of revision compared to metal-on-polyethylene bearings,13 and identified cirrhosis as a risk factor for postoperative complications 14…”

Do different types of bearings and noise from total hip arthroplasty influence hip-related pain, function, and quality of life postoperatively?

“…The main cause of revision for CoC THA was dislocation (1.2%), and for MoM THA it was aseptic loosening (1.9%) (Varnum et al. 2015a, b). As survival and causes of revision differed for different types of bearings, one could also ask whether patient-reported outcomes (PROs) would be different for different bearings in THA.…”