This registry study of 420,339 primary THAs with uncemented cups analyzed how bearing surface choice affects implant survival. It is the first NJR study to stratify conventional and cross-linked polyethylene when comparing bearing combinations. The primary question: which bearing surface gives the lowest revision risk, including in patients under 55?
When counseling a 48-year-old active patient requesting THA, the bearing surface decision carries measurable survivorship consequences at 10 years.
This study's key contribution is separating conventional from cross-linked PE in the NJR dataset — prior registry analyses lumped them together, obscuring the real benefit of XLPE. The takeaway is simple: XLPE dramatically reduces aseptic loosening-driven revision, and this benefit is preserved in younger patients.
Ceramic-on-ceramic is commonly recommended for young patients because of low volumetric wear, but registry data tell a more nuanced story. CoC has a 5.6-fold higher implant fracture hazard, and its overall revision rate at 10 years (3.47%) is no better than the aggregate PE group — largely because fracture and pain-related revisions offset the wear advantage.
For boards and clinical practice, two additional findings are worth internalizing. Cementless stems carry a 35% higher revision hazard than cemented stems in this model, independent of bearing surface. Femoral head size ≤28 mm more than doubles dislocation revision risk, independent of bearing material. Bearing surface is one lever — fixation and head size are others that compound the risk.
This registry study of 420,339 primary THAs with uncemented cups analyzed how bearing surface choice affects implant survival. It is the first NJR study to stratify conventional and cross-linked polyethylene when comparing bearing combinations. The primary question: which bearing surface gives the lowest revision risk, including in patients under 55?
When counseling a 48-year-old active patient requesting THA, the bearing surface decision carries measurable survivorship consequences at 10 years.
This study's key contribution is separating conventional from cross-linked PE in the NJR dataset — prior registry analyses lumped them together, obscuring the real benefit of XLPE. The takeaway is simple: XLPE dramatically reduces aseptic loosening-driven revision, and this benefit is preserved in younger patients.
Ceramic-on-ceramic is commonly recommended for young patients because of low volumetric wear, but registry data tell a more nuanced story. CoC has a 5.6-fold higher implant fracture hazard, and its overall revision rate at 10 years (3.47%) is no better than the aggregate PE group — largely because fracture and pain-related revisions offset the wear advantage.
For boards and clinical practice, two additional findings are worth internalizing. Cementless stems carry a 35% higher revision hazard than cemented stems in this model, independent of bearing surface. Femoral head size ≤28 mm more than doubles dislocation revision risk, independent of bearing material. Bearing surface is one lever — fixation and head size are others that compound the risk.