Anin vitro investigation of diamond-like carbon as a femoral head coating

Abstract

Wear of polyethylene acetabular components of hip implants is a significant clinical problem. In prosthetic hip surgery, polyethylene wear is identified as a factor that limits the life of the implant; it is known that the production of debris can cause adverse tissue reactions that may lead to extensive bone loss around the implant, and consequently loosening of the fixation. A new class of so-called Diamond-Like Carbon coatings, applied to titanium femoral heads was compared to ceramic and metallic heads in terms of wear behavior against UHMWPE using a hip joint simulator with a bovine calf serum lubricant. A thin film of Diamond-Like Carbon was deposited directly onto titanium (Ti6Al4V) head using chemical vapor deposition. The wear of polyethylene coupled with Diamond-Like Carbon coated femoral heads was comparable to that obtained with the polyethylene coupled with commercial alumina femoral heads.

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

“…A number of papers do not state the type of DLC used [4,[40][41][42][43][46][47][48], while those that do state they are using ta-C or a-C:H, they fail to mention the composition ratio. While the manufacturing method and the source material enable an estimation of the composition, without knowing the exact conditions during the deposition, it remains little more than a guess.…”

“…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.…”

“…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.…”

“…Affatoto et al [41] suggested that the poor performance of the DLC films in general is due to their adhesion on the substrate as no interlayer was used. Ti and Co alloys are both poor at forming strong interactions with the DLC, as the atoms might leach across to the film and weaken the interface between the coating and surface.…”

Mechanical and tribological behavior of silicon nitride and silicon carbon nitride coatings for total joint replacements

“…Different surface treatments and coatings have been investigated for the bearing surfaces between the femoral head and the acetabular cup in hip implants, such as TiN (Harman et al, 1997;Pappas et al, 1995;Teresa Raimondi and Pietrabissa, 2000), diamond-like carbon (Affatato et al, 2000;Fisher et al, 2002;Lappalainen et al, 1998), CrN (Fisher et al, (2002), CrCN (Fisher et al, 2002), ZrO 2 , and Al 2 O 3 (Yen and Hsu, 2001). However, insufficient adhesion and coating artifacts, such as droplets, have been reported as major concerns for these coatings.…”