Study on long life of artificial joints by investigating optimal sliding surface geometry for improvement in wear resistance

• Published in: Precision engineering Vol. 33; no. 4; pp. 492 - 498
• Main Authors: Sawano, Hiroshi, Warisawa, Shin’ichi, Ishihara, Sunao
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2009; Elsevier
• Subjects: Abrasive waterjet; Applied sciences; Dimple structure; Effective life of artificial joint; Exact sciences and technology; Mechanical engineering. Machine design; Precision engineering, watch making; Scratch marks; Sliding surface; Wear resistance; Sliding surface; Scratch marks; Dimple structure; Wear resistance; Abrasive waterjet; Effective life of artificial joint; Ultra high molecular weight ethylene polymer; Human; Polyethylene; Implant; Prosthesis; Precision engineering; Metal; Joint; Experimental study; Osteoarticular system; Smooth surface
• ISSN: 0141-6359; 1873-2372
• DOI: 10.1016/j.precisioneng.2009.01.005

The effective life of artificial joints is approximately 15 years. A smooth metal sliding surface is presumably the most suitable when manufacturing artificial joints; however, the relationship between the characteristics of metal sliding surface and ultra high molecular polyethylene (UHMWPE) wear has not been confirmed. Further, there is no apparent proof that a smooth surface is the optimal option for the improvement in the wear resistance of artificial joints. In this study, we investigated the mechanism of UHMWPE wear and proved that scratch marks caused by a sliding motion against the metal surface are the prime cause of UHMWPE wear. Furthermore, we used a micro-dimpled surface as an effective sliding surface to reduce the UHMWPE wear. A 2-axes pin-on-plate sliding test proved that the life of artificial joints can be extended to approximately 35 years by using a micro-dimpled surface with 1-μm deep dimples.