Comparison of Diamond‐Like‐Carbon and Alumina‐Oxide articulating with Polyethylene in Total Hip Arthroplasty

Abstract

To reduce wear in joint bearings of total hip arthroplasty (THA) is the most important issue for improving long term results and implant survival. Due to low wear rates and excellent tribological features in simulator tests Diamond-Like-Carbon coating (DLC) of femoral balls is still discussed as an alternative articulation in THA. This clinical prospective study compares survivorship of DLCcoated femoral heads and of Aluminia-Oxide-(Al 2 O 3 ) heads articulating with Polyethylene (PE).Over a period of two years 101 THA with DLC-coated heads and PE cups (DLC-group) and another 101 THA consisting of Al 2 O 3 heads (Al 2 O 3 -group) and PE cups as well were implanted. Both articulations were based on the same type of cementless hip joint prosthesis. All hips were implanted by one surgeon in consecutive series consisting of 51 Al 2 O 3 and 101 DLC-articulations and further 50 Al 2 O 3 . All perioperative and follow-up data was processed with SPSS J . Survival of THA in both groups was evaluated according to Kaplan-Meier survivorship analysis with an intervall of 90 months (range:78-101). Qualitative surface analysis was performed in nineteen retrieved DLC-heads which were revised for aseptic loosening using field scanning electron microscopy (FE-SEM, XL 30 SFEG Philips, Eindoven NL).178 patients (88.2 %) were evaluated for follow-up. Fourteen patients died meantimes (nine DLC, five Al 2 O 3 ) with the implant components not revised. Ten patients (five DLC, five Al 2 O 3 ) were lost to follow-up. Both groups were comparable regarding patient age, weight and indications for THA with a normal distribution. Survivorship analysis for aseptic loosening 8.5 years following implantation resulted in a significant difference between both groups with a 54 % survival for DLC/PE compared to 88 % for Al 2 O 3 /PE bearings (p <0.001). No correlation to variables as age, gender or bodyweight could be detected. Surfaces of nineteen retrieved DLC-heads showed numerous smallest pits of the diamond-carbon layers in different quantity. SEM showed delamination of the carbon layer which caused excessive debris of polyethylene and in some cases even of the metallic substrate of the heads.Despite modern manufacturing technology and excellent experimental results for its tribochemical characteristics and wear, even "new" DLC-coating of femoral heads is to be considered critically due to very high rates of clinical failure. Obwohl moderne Fertigungstechniken mit sehr guten experimentellen Ergebnissen hinsichtlich Tribochemie und Verschleiß verbunden sind, müssen DLC-Beschichtungen zukünftig für diese Anwendung angesichts der immens hohen klinischen Versagensquote mit größter Zurückhaltung betrachtet werden.Schlagworte: Diamond-Like-Carbon,

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

“…Indeed this has been identified as the main cause for implant failure in the explant study by Taeger et al, as observed in Fig. 5 [38]. Fracture and cracking was noted along the wear scars by Fisher et al [42], shown in Fig.…”

“…As the explant study (Taeger et al [38]) also suggests that the wear debris is the likely cause of premature biological failure, the main aim for improvement in the coatings is to make them more resistant to wear (resulting in less debris) or to make the debris less harmful to the body.…”

“…However, Taeger et al [38] compared the performance of a DLC coated Titanium alloy (Ti-6Al-4V) head with Al 2 O 3 ceramic heads, both wearing against a UHMWPE cup. 202 patients were submitted to the trial, with 101 having an implant with a coating and 101 having ceramic head.…”

“…With new advances in deposition methods and interlayer usage it would be expected that coating performance should improve significantly. Taeger et al [38] paper concluded that although the DLC has excellent properties and shows excellent promise, the differences between the in vitro testing methods and conditions, from those experienced in vivo, were major contributing factors to the resultant implant performance. Therefore although in vitro tests are not as accurate they are still important, but the reasons for the difference between in vivo and in vitro need to be explored…”

Reduced Wear of Cross-linked UHMWPE Using Magnesia-stabilized Zirconia Femoral Heads in a Hip Simulator

“…The DLC deposition process can be tailored to produce a strong amorphous film with no grain boundaries and hardness values ranging from 10 to 80 GPa [33]. However, DLCcoated titanium alloy femoral heads failed in clinical use [47], and DLC-coated CoCr femoral heads reportedly do not reduce wear compared with uncoated CoCr heads in hip simulator tests [18], but the durability and wear performance of DLC-coated ceramic materials is unknown. DLC-coated Mg-PSZ reportedly forms a stronger construct than DLC-coated CoCr [35], suggesting an improved resistance to abrasive wear.…”