Reduction of wear in total hip replacement prostheses by amorphous diamond coatings

Abstract

Wear-debris-induced periprosthetic bone loss and aseptic loosening is regarded as the main long-term problem of total hip replacements (THRs). In this study the amount of wear debris from articulating surfaces of THRs was reduced so as to be close to negligible by the use of high-quality amorphous diamond (AD) coatings deposited by pulsed plasma arc techniques. The wear rates determined in a commercial hip simulator for 15 million walking cycles (corresponding to about 15 years of clinical use) in serum lubrication were even 1,000,000 times lower than the clinical values for conventional THRs (polyethylene-metal or metal-metal pairs). Elimination of wear debris and good biomechanical performance should provide a substantial improvement of the clinical longevity of the THRs.

Diamond like carbon coatings for potential application in biological implants—a review

“…Previous research has suggested early delamination based failures, and this indeed occurred in large numbers of implanted DLC coated hip joints in the past [7]. Testing by Lappalainen et al [39], and to a lesser extent Dowling et al [40] and Oñ ate et al [50] tested over 15 million, 6 million and 5 million cycles on joint simulators respectively(Lappalainen estimated 1 million cycles to be equivalent to 1 year in use). These long term tests showed good results in wear reduction and life of the coating.…”

“…However, the results to date are conflicting, both Lappalainen [39,44] and Oñ ate [50] mention the use of an interlayer, but provide no information about what type. Dowling [40] specifically mentions no interlayer being used, but gets a better wear reduction, over a longer testing period than those of Oñ ate.…”

“…The results showed similarities, with all 3 tests showing a reduction in wear compared to uncoated tests, however to different levels. Tiainen [27] showed a reduction in wear by a factor of 10 5 -10 6 , Lappalainen et al [39] only showing a reduction of 10 2 -10 4 and Fisher et al [42] only showing a wear rate reduction of 26.The only notable differences between these tests is that Fisher et al tested the DLC coating against a different hard coating (CrN) not a 2nd DLC surface and a slightly different testing rig Papers that use DLC on UHMWPE(Saikko et al [43], Affatato et al [41] and Dowling et al [40]) use similar testing periods and testing solutions. However, Affatato et al [41] used double the test load that Saikko et al [43] employed.…”

“…Out of 14 reports [4,27,[39][40][41][42][43][44][45][46][47][48][49][50] there appeared to be no standardisation between choice of testing conditions and counter surface.…”

Aseptic Loosening of Total Hip Arthroplasty as a Result of Local Failure of Tissue Homeostasis

“…the long-term tolerance to implants (Korhonen et al 2005). Another method suitable for implant testing is computer-controlled simulation of real implants (Lappalainen et al 2003). Randomized controlled clinical trials are the best way to evaluate specific implants in clinical practice.…”