Less wear with aluminium-oxide heads than cobalt-chrome heads with ultra high molecular weight cemented polyethylene cups: a ten-year follow-up with radiostereometry

Int Orthop. 2012 Mar;36(3):485-90. doi: 10.1007/s00264-011-1334-3. Epub 2011 Aug 26.

Abstract

Purpose: Wear is a major contributor to osteolysis and aseptic loosening of total hip replacements (THR). Both alumina (Al(2)O(3)) and cobalt-chrome (CoCr) femoral heads are commonly used. We investigated wear comparing alumina heads to cobalt-chrome heads against conventional cemented polyethylene (PE) cups for up to ten years.

Methods: Linear wear was measured with radiostereometry (RSA). Our material was derived from two prospective randomised trials that investigated fixation of femoral stems, not wear, and was evaluated retrospectively (Level III).

Results: The mean (95% CI) proximal head penetration was 0.96 mm (0.68-1.23) in the cobalt-chrome group and 0.42 mm (0.30-0.53) in the alumina group at ten years (P = 0.001). The mean (95% CI) 3D penetration was 1.07 mm (0.79-1.35) and 0.53 mm (0.38-0.63), respectively, at ten years (P = 0.001).

Conclusion: Alumina heads performed better than cobalt-chrome heads in this study after ten-year follow-up.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aluminum Oxide*
  • Cementation
  • Chromium Alloys*
  • Coated Materials, Biocompatible
  • Cobalt*
  • Equipment Failure Analysis
  • Female
  • Follow-Up Studies
  • Hip Prosthesis / adverse effects*
  • Humans
  • Male
  • Middle Aged
  • Osteolysis / etiology
  • Polyethylene*
  • Prospective Studies
  • Prosthesis Design
  • Prosthesis Failure / etiology*

Substances

  • Chromium Alloys
  • Coated Materials, Biocompatible
  • Cobalt
  • Polyethylene
  • Aluminum Oxide