For the improvement of surface roughness,
titanium joint
arthroplasty (TJA) components are grit-blasted with Al2O3 (
corundum) particles during manufacturing. There is an acute concern, particularly with uncemented implants, about polymeric, metallic, and
corundum debris generation and accumulation in TJA, and its association with
osteolysis and implant loosening. The surface morphology, chemistry, phase analysis, and surface chemistry of retrieved and new Al2O3 grit-blasted
titanium alloy were determined with scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and confocal
laser fluorescence microscopy, respectively. Peri-prosthetic soft tissue was studied with histopathology. Blasted retrieved and new stems were exposed to human mesenchymal stromal stem cells (BMSCs) for 7 days to test biocompatibility and cytotoxicity. We found metallic particles in the peri-prosthetic soft tissue.
Ti6Al7Nb with the residual Al2O3 particles exhibited a low cytotoxic effect while polished
titanium and ceramic disks exhibited no cytotoxic effect. None of the tested materials caused cell death or even a zone of inhibition. Our results indicate a possible
biological effect of the blasting debris; however, we found no significant toxicity with these materials. Further studies on the optimal size and properties of the blasting particles are indicated for minimizing their adverse
biological effects.