Early detection of prosthetic-hip loosening. Comparison of low- and high-viscosity bone cement

In 1987, we reported the 1-year migration of the prosthetic components in 16 hips followed by roentgen stereophotogrammetry after fixation with either low- or high-viscosity cement. We now report the migration of these prosthetic components during another 2 postoperative years. Eight acetabular components, four in each group, migrated cranially; and four femoral components, three in the low-viscosity and one in the high-viscosity group, migrated distally. All but two migrations were obvious 4 months postoperatively, which indicates that what is called late loosening is the result of late detection rather than of late occurrence of loosening. Low-viscosity cement did not provide improved prosthetic fixation.