Does Acetabular Inclination Angle Affect Survivorship of Alumina-ceramic Articulations?

Abstract

Background Reports in the literature have linked high acetabular inclination angles to increased wear of ceramicon-ceramic bearings. However, many of these studies were only conducted in vitro and did not address the clinical relevance of such findings. Questions/purposes We therefore determined: (1) whether the cup inclination angle influences survival or function in patients with ceramic-on-ceramic implants; (2) the incidence of radiolucencies, osteolysis, and subsidence of ceramic-on-ceramic implants; and (3) whether the survival rate higher for ceramic-on-ceramic THAs than for conventional metal-on-polyethylene THAs.Methods We retrospectively reviewed 537 THAs performed in 512 prospectively followed patients having THA between October 1996 and October 2000. Eleven patients (12 hips) were lost to followup before 2 years, leaving 501 patients (525 THAs); of these, 421 were alumina ceramic-on-ceramic articulations and 104 cobaltchromium-on-polyethylene. The mean age was 54 years. We determined acetabular cup inclination angles, Harris hip scores, Health-Status-Questionnaire-12 scores, and presence and location of any radiolucencies, osteolysis, or radiographic subsidence. We compared survival using the Kaplan-Meier method. The minimum followup was 24 months (mean, 59 months; range, 24-120 months). Results Twenty-two of the 424 THAs (4.2%) were revised. We observed no difference in clinical or radiographic outcomes with respect to cup inclination angles. Radiographically, two loose acetabular components and two femoral components had subsided. The 5-year survival rate was slightly higher for ceramic-on-ceramic bearings (98%) than for metal-on-polyethylene (92%).

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

“…In the Australian Orthopaedic Association National Joint Replacement Registry (AOA NJRR), the cumulative incidence of revision of CoC THA, with OA as diagnosis, at 10 years was 5.3%, which is similar to our findings after 8.7 years of follow-up. In studies with smaller series, a 5-year survival of 98% ( Johansson et al 2011 ) and a 6.7-year survival of 94–98% ( Garcia-Rey et al 2009 ) were found, corresponding to our findings. The main cause of revision in both studies was aseptic loosening.…”

“…Thus, simulator studies have shown less wear with CoC bearings, which—together with more bio-inert debris than polyethylene wear debris ( Christel 1992 )—may reduce the risk of aseptic loosening in CoC THAs, although this has not yet been shown in any study and should only become apparent with longer follow-up time. In the present study and in the above-mentioned studies with short- to medium-term follow-up ( Garcia-Rey et al 2009 , Johansson et al 2011 , Khatod et al 2014 ), revision due to aseptic loosening could certainly be related to fixation of the components rather than to wear.…”

“…Survivorship of CoC THAs after a mean follow-up time of 5–12 years has been described in some previous studies ( Garcia-Rey et al 2009 , Johansson et al 2011 , D’Antonio et al 2012 ), but these studies had small sample sizes and involved very few hospitals and clinics, thus reducing the generalizability of the findings. Based on data from the Danish Hip Arthroplasty Registry (DHR), we therefore conducted a population-based cohort study to determine the revision risk and to investigate the causes of revision of cementless CoC THAs, comparing them to those of “standard” MoP THAs.…”

Edge‐loading severity as a function of cup lip radius in metal‐on‐metal total hips—A finite element analysis

“…The effect of cup orientation on bearing surface wear of hard bearings has been extensively investigated. Although most clinical retrieval and simulator studies identified increased bearing surface wear for high inclination,5, 12–14 some did not 16, 31. Similarly, controversy exists regarding acetabular anteversion effects; both increased15, 16 and decreased11 wear have been measured.…”

Biomechanics of failure modalities in total hip arthroplasty

“…Therefore, mesh zoning resolution, which was determined from mesh sensitivity convergence studies, was approximately equal for the entire contact region (shown here as the outlined elements near the edge of the cup). The edge loading challenge investigated was a trunk leaning maneuver, such as when tying shoes 67 .The motion and loading inputs were determined from kinematic and inverse dynamic data from human-subject optoelectronic motion capture 56 , some have not 224,232 . Similarly, controversy exists regarding acetabular anteversion effects, with both increased 212,224 and decreased 222 wear having been measured.…”