POROUS-COATED ACETABULAR COMPONENTS: STUDY OF TWO CUP DESIGNS

Background/Introduction Total hip arthroplasty (THA) using cementless acetubular components is commonly performed with, porous-coated cups. This study contrasts two cup designs implanted from January 1990 through December 2024. Materials and Methods We report primary THAs using two acetabular components (Duraloc or Pinnacle cups, DePuy Synthes, Warsaw, IN). The Duraloc cups were used from 1990 – 2007 and the Pinnacle cups were used from 2000 – 2024. 15,981 THAs have a mean follow-up of 7.2±6.4 years. Cox regression was used to evaluate how cup design, age at surgery, sex, body mass index, surgical approach, liner material, and femoral head diameter were associated with revision for aseptic cup loosening and revision for any reason. Results Aseptic septic loosening was 0.2% (6/3302) of the Duraloc cups versus 0.1% (11/12,679) of the Pinnacle cups but a Cox regression found no difference in risk of revision (p=0.48). Component revision for any reason was 8.9% (295/3302) of the Duraloc cups and 2.2% (282/12,679) of the Pinnacle cups. A Cox regression found that a crosslinked liner decreased the risk of revision (HR=0.419, 95%, CI, 0.341 to 0.514, p<0.001), each year increase in age at surgery decreased risk (HR=0.978, 95% CI 0.971 to 0.985, p<0.001), the posterior approach increased the risk (HR=1.512, 95% CI 1.249 to 1.831, p<0.001) but there was no difference in revision risk based on cup design (p=0.97). Discussion and Conclusion Over 35-years, the use of porous-coated hemispheric acetabular components has been associated with low rates of aseptic cup loosening. The transition to crosslinked polyethylene liners has reduced component revisions.