Abstract
Introduction
Cobalt chrome femoral head has been used widely in total hip arthroplasty and has shown favorable outcome. However, there is still of concern of potential metal toxicity from the wear debris. In the other hand, titanium is well known for its biocompatibility but it is not used in bearing surface of arthroplasty due to its brittleness. Recently, coating of the prosthesis using plasma electrolytic oxidation (PEO) has shown favorable surface protection. Thus, in this study, we tried to find out whether the PEO coating on the titanium surface would provide surface protection.
Materials and methods
Five Titanium alloy (Ti-6Al-4V) ball mimicking femoral head was manufactured and was coted using plasma electrolytic oxidation. Wear rate was tested using validated wear tester with 10N compression force at 80rpm. The amount of wear was detected by measuring change of weight after wear test was completed. This was compared with femoral head manufactured with titanium alloy without PEO coating. Toxicity of the debris was also tested using MTT assay with human osteoblast cell line.
Results
Compare to the base titanium metal, PEO coated metal head has shown to provide surface protection. The wear rate has significantly decreased with PEO coating (median value : 0.00015g/mm2 vs 0.00006 g/mm2). MTT assay revealed no cytotoxicity with the amount of debris generated from the wear test.
Conclusion
The result of the current study indicate that the PEO coating on the titanium femoral head can significantly decrease the wear rate and is non cytotoxic. This indicates that the femoral head manufactured with titanium alloy and PEO coating maybe a potential alternative to be used in total hip arthroplasty.
